Scholars@Duke
Stephen L Craig

Stephen L Craig

William T. Miller Distinguished Professor of Chemistry
Chemistry
stephen.craig@duke.edu
Box 90346, Durham, NC 27708-0346
3221 French Family Science Cen, 124 Science Drive, Durham, NC 27708

Selected Publications

Optimizing the Stability of Viral Nanoparticles: Engineering Strategies, Applications, and the Emerging Concept of the Virophore.

Journal Article Journal of the American Chemical Society · January 2026 Nanoparticles derived from plant viruses and bacteriophages are self-assembling structures that can be functionalized for broad applications in drug delivery, vaccine formulation, and imaging, as well as the engineering of nanomaterials, and nanoscale temp ... Full text Cite

Reimagining Polymer Networks from Molecule to Material

Journal Article Macromolecules · December 23, 2025 Polymer networks are complex materials with a broad distribution of molecular states, making it challenging to establish direct connections between the structure of individual network components and macroscopic material behavior. Recent advancements in mec ... Full text Cite

Switching and Quantifying the Single-Molecule Mechanochemical Reactivity of Four-Membered Carbocycle Mechanophores within a Single, Photoswitchable Polymer Strand.

Journal Article Journal of the American Chemical Society · December 2025 The reactivity of four-membered carbocycle mechanophores, such as cyclobutane (CB), cyclobutene (CBE), and benzocyclobutene (BCB), has been explored in the context of fundamental reaction mechanisms and the manipulation of polymer network properties. Despi ... Full text Cite

Toughening 3D printed elastomers using mechanophore crosslinkers.

Journal Article Soft matter · November 2025 Elastomeric materials are widely used in industrial application sectors including construction, automotives, soft robotics, and biomedicine. Light-based three-dimensional (3D) printing enables the manufacturing of elastomeric polymer networks with geometri ... Full text Cite

Tetrafunctional cyclobutanes tune toughness via network strand continuity.

Journal Article Nature chemistry · November 2025 Customizing the toughness of polymer networks independently of their chemical composition and topology remains an unsolved challenge. Traditionally, polymer network toughening is achieved by using specialized monomers or solvents or adding secondary networ ... Full text Cite

Strain-dependent enantioselectivity in mechanochemically coupled catalytic hydrogenation

Journal Article Nature Synthesis · October 1, 2025 The ultimate realization of top-down atomic manipulation is to push or pull molecules in a way that changes their function, such as catalysis. The forces in a stretched polymer distort molecular conformation in ways that couple to reactivity, but the use o ... Full text Cite

High-Throughput Discovery of Ferrocene Mechanophores with Enhanced Reactivity and Network Toughening.

Journal Article ACS central science · October 2025 Mechanophores are molecules that undergo chemical changes in response to mechanical force, offering unique opportunities in chemistry, materials science, and drug delivery. However, many potential mechanophores remain unexplored. For example, ferrocenes ar ... Full text Cite

Tuning the Ultimate Strain of Single and Double Network Gels Through Reactive Strand Extension.

Journal Article ACS central science · October 2025 The stretchability (ability to be elongated) and toughness (capacity to absorb energy before breaking) of polymer network materials, such as elastomers and hydrogels, often determine their utility and lifetime. Direct correlations between the molecular beh ... Full text Cite

Improving Catalytic Enantioselectivity of Hydrogenation through Swelling-Induced Molecular Tension in Polymer Networks.

Journal Article Journal of the American Chemical Society · August 2025 Herein, we report that molecular tension generated by the swelling of a polyacrylate network containing a chiral [Biphep]Rh(I) catalyst as a tension-bearing, bis-tethered cross-linker enhances the enantioselectivity of hydrogenation of methyl 2-acetamidoac ... Full text Cite

Single-Molecule Force Spectroscopy Studies of Oxy Substituent Effects on the Reactivity of gem-Dihalocyclopropane Mechanophores

Journal Article Macromolecules · June 10, 2025 Oxy-substituted gem-dihalocyclopropanes (gDHCs) have recently found utility as mechanoacids for the generation of HCl or HF following force-assisted ring opening along polymer backbones. Here, we employ single-molecule force spectroscopy (SMFS) to quantify ... Full text Cite

Rubber that lasts longer

Journal Article Nature Sustainability · June 1, 2025 Natural rubber has many uses in a variety of industries, enabled by ‘crosslinking’ between its tangled polymers, which creates elasticity. But rubber can crack and suffer fatigue. It is now shown that reducing the crosslink density in highly entangled natu ... Full text Cite

Structure-property relationships for the force-triggered disrotatory ring-opening of cyclobutene.

Journal Article Chemical science · April 2025 Symmetry forbidden reactions are notoriously difficult to study experimentally, for the simple reason that their competing symmetry allowed pathways typically dominate. Covalent polymer mechanochemistry offers an opportunity to broaden access to symmetry f ... Full text Cite

John Brauman (1937–2024): Physical organic chemist, sage, and servant of science

Journal Article Proceedings of the National Academy of Sciences · March 25, 2025 Full text Cite

Fracture of polymer-like networks with hybrid bond strengths

Journal Article Journal of the Mechanics and Physics of Solids · February 1, 2025 The design and functionality of polymeric materials hinge on failure resistance. While molecular-level details drive crack evolution in polymer networks, the connection between individual chain scission and bulk failure remains unclear and difficult to pro ... Full text Cite

Enabling Selective Mechanochemical Scission of Network Crosslinks by Exchanging Single Carbon Atoms for Silicon.

Journal Article Journal of the American Chemical Society · February 2025 The tearing of a polymer network arises from mechanochemically coupled bond-breaking events in the backbone of a polymer chain. An emerging research area is the identification of molecular strategies for network toughening, such as the strategic placement ... Full text Cite

Force-Activated Spin-Crossover in Fe2+ and Co2+ Transition Metal Mechanophores.

Journal Article Inorganic chemistry · January 2025 Transition metal mechanophores exhibiting force-activated spin-crossover are attractive design targets, yet large-scale discovery of them has not been pursued due in large part to the time-consuming nature of trial-and-error experiments. Instead, we levera ... Full text Cite

Advancing the Mechanosensitivity of Atropisomeric Diarylethene Mechanophores through a Lever-Arm Effect.

Journal Article Journal of the American Chemical Society · January 2025 Understanding structure-mechanical activity relationships (SMARs) in polymer mechanochemistry is essential for the rational design of mechanophores with desired properties, yet SMARs in noncovalent mechanical transformations remain relatively underexplored ... Full text Cite

Isomer-driven polymerization, depolymerization, and reconstruction

Journal Article Polymer Chemistry · November 20, 2024 We report that differences in ring strain enthalpy between cis and trans isomers of sila-cycloheptene provide a driving force for both polymerization and depolymerization via olefin metathesis. A need for new methods to reintroduce the low-strain isomer in ... Full text Cite

Controlling the Microstructure and Mechanical Response of Polybutadiene Elastomers Through Phosphite Inhibited Ring-Opening Metathesis Polymerization

Journal Article Macromolecules · November 12, 2024 With microstructures that typically favor crystallization at low temperatures, commercial polybutadiene elastomers often suffer from poor toughness and limited elongation when utilized in applications near room temperature. By controlling competition betwe ... Full text Cite

Toughening and Imparting Deconstructability to 3D-Printed Glassy Thermosets with "Transferinker" Additives.

Journal Article Advanced materials (Deerfield Beach, Fla.) · November 2024 Thermoset toughness and deconstructability are often opposing features; simultaneously improving both without sacrificing other mechanical properties (e.g., stiffness and tensile strength) is difficult, but, if achieved, could enhance the usage lifetime an ... Full text Cite

Fluorination Affects the Force Sensitivity and Nonequilibrium Dynamics of the Mechanochemical Unzipping of Ladderanes.

Journal Article Journal of the American Chemical Society · November 2024 When multiple reaction steps occur before thermal equilibration, kinetic energy from one reaction step can influence overall product distributions in ways that are not well predicted by transition state theory. An understanding of how the structural featur ... Full text Cite

The tension-activated carbon–carbon bond

Journal Article Chem · October 10, 2024 Mechanical force drives distinct chemical reactions; yet, its vectoral nature results in complicated coupling with reaction trajectories. Here, we utilize a physical organic model inspired by the classical Morse potential and its differential forms to iden ... Full text Cite

A simple swell-and-click method for the covalent attachment of virus-like particles to polymer hydrogels

Journal Article Materials Today Chemistry · June 1, 2024 Plant virus-like particles (VLPs) are biocompatible, non-infectious nanomaterials with promising applications as immunotherapeutics and vaccines. However, slow-release VLP formulations are needed to achieve long-term efficacy without repeated administratio ... Full text Cite

Effect of the Activation Force of Mechanophore on Its Activation Selectivity and Efficiency in Polymer Networks.

Journal Article Journal of the American Chemical Society · May 2024 In recent decades, more than 100 different mechanophores with a broad range of activation forces have been developed. For various applications of mechanophores in polymer materials, it is crucial to selectively activate the mechanophores with high efficien ... Full text Cite

A polyelectrolyte handle for single-molecule force spectroscopy

Journal Article Journal of Polymer Science · April 1, 2024 Single-molecule force spectroscopy is a powerful tool for the quantitative investigation of the biophysics, polymer physics and mechanochemistry of individual polymer strands. One limitation of this technique is that the attachment between the tip of the a ... Full text Cite

A Thermally Stable SO2-Releasing Mechanophore: Facile Activation, Single-Event Spectroscopy, and Molecular Dynamic Simulations.

Journal Article Journal of the American Chemical Society · April 2024 Polymers that release small molecules in response to mechanical force are promising candidates as next-generation on-demand delivery systems. Despite advancements in the development of mechanophores for releasing diverse payloads through careful molecular ... Full text Cite

Self-Amplified HF Release and Polymer Deconstruction Cascades Triggered by Mechanical Force.

Journal Article Journal of the American Chemical Society · April 2024 Hydrogen fluoride (HF) is a versatile reagent for material transformation, with applications in self-immolative polymers, remodeled siloxanes, and degradable polymers. The responsive in situ generation of HF in materials therefore holds promise for ... Full text Cite

Angle-strained sila-cycloalkynes.

Journal Article Chemical communications (Cambridge, England) · April 2024 Second row elements in small- and medium-rings modulate strain. Herein we report the synthesis of two novel oligosilyl-containing cycloalkynes that exhibit angle-strain, as observed by X-ray crystallography. However, the angle-strained sila-cyclooctynes ar ... Full text Cite

Modulating Transition Metal Reactivity with Force

Journal Article Chemcatchem · March 8, 2024 The reactivity and selectivity of a transition metal catalyst is intimately related to its ligand-sphere geometry, and, in many cases, the ideal ligand geometry for one step of a catalytic cycle is poorly matched to the ideal ligand geometry for another. F ... Full text Cite

Virus-like Particles Armored by an Endoskeleton.

Journal Article Nano letters · March 2024 Many virus-like particles (VLPs) have good chemical, thermal, and mechanical stabilities compared to those of other biologics. However, their stability needs to be improved for the commercialization and use in translation of VLP-based materials. We develop ... Full text Cite

3D printed modular piezoionic sensors using dynamic covalent bonds

Journal Article Rsc Applied Polymers · February 20, 2024 Flexible and lightweight sensors can assess their environment for a broad range of applications that include wearables for health monitoring and soft robotics. While 2D and 3D printing enables control over sensor design in multiple dimensions, customizabil ... Full text Cite

Mechanically Triggered Polymer Deconstruction through Mechanoacid Generation and Catalytic Enol Ether Hydrolysis.

Journal Article Journal of the American Chemical Society · February 2024 Polymers that amplify a transient external stimulus into changes in their morphology, physical state, or properties continue to be desirable targets for a range of applications. Here, we report a polymer comprising an acid-sensitive, hydrolytically unstabl ... Full text Cite

Solvent Polarity Effects on the Mechanochemistry of Spiropyran Ring Opening.

Journal Article Journal of the American Chemical Society · February 2024 The spiropyran mechanophore (SP) is employed as a reporter of molecular tension in a wide range of polymer matrices, but the influence of surrounding environment on the force-coupled kinetics of its ring opening has not been quantified. Here, we report sin ... Full text Cite

Mechanochemistry of Pterodactylane.

Journal Article Journal of the American Chemical Society · January 2024 Pterodactylane is a [4]-ladderane with substituents on the central rung. Comparing the mechanochemistry of the [4]-ladderane structure when pulled from the central rung versus the end rung revealed a striking difference in the threshold force of mechanoact ... Full text Cite

Soft matter roadmap

Journal Article Jphys Materials · January 1, 2024 Soft materials are usually defined as materials made of mesoscopic entities, often self-organised, sensitive to thermal fluctuations and to weak perturbations. Archetypal examples are colloids, polymers, amphiphiles, liquid crystals, foams. The importance ... Full text Cite

Reactivity-Guided Depercolation Processes Determine Fracture Behavior in End-Linked Polymer Networks.

Journal Article ACS macro letters · December 2023 The fracture of polymer networks is tied to the molecular behavior of strands within the network, yet the specific molecular-level processes that determine the mechanical limits of a network remain elusive. Here, the question of reactivity-guided fracture ... Full text Cite

Metal identity effects in the fracture behavior of coordinatively crosslinked elastomers

Journal Article Polymer · October 20, 2023 Polymers comprising polybutadiene backbones with 2,6-bis(1′-methyl-benzimidazolyl)pyridine (MeBip) sidechains were crosslinked by complexation with two different metal salts, either with copper(II) trifluoromethanosulfonate or with iron(II) trifluoromethan ... Full text Cite

Mechanochromism and Strain-Induced Crystallization in Thiol-yne-Derived Stereoelastomers.

Journal Article Advanced materials (Deerfield Beach, Fla.) · October 2023 Most elastomers undergo strain-induced crystallization (SIC) under tension; as individual chains are held rigidly in a fixed position by an applied strain, their alignment along the strain field results in a shift from strain-hardening (SH) to SIC. A simil ... Full text Open Access Cite

Polymer Networks with Cubic, Mixed Pd(II) and Pt(II) M6L12 Metal-Organic Cage Junctions: Synthesis and Stress Relaxation Behavior.

Journal Article Journal of the American Chemical Society · October 2023 Metal-organic cages/polyhedra (MOCs) are versatile building blocks for advanced polymer networks with properties that synergistically blend those of traditional polymers and crystalline frameworks. Nevertheless, constructing polyMOCs from very stable Pt(II ... Full text Cite

Systematic Investigation of Silicon Substitution on Single Macromolecule Mechanics

Journal Article Macromolecules · September 12, 2023 Four unsaturated poly(carbooligosilane)s (P1-P4) were prepared via acyclic diene metathesis polycondensation of new oligosilane diene monomers (1-4). These novel polymers with varying main-chain Si incorporation have high trans internal olefin stereochemis ... Full text Cite

Force-Modulated C-C Reductive Elimination from Nickel Bis(polyfluorophenyl) Complexes

Journal Article Organometallics · August 14, 2023 We have analyzed the rate of C(sp2)-C(sp2) reductive elimination from nickel(II) bis(2,4,6-trifluorophenyl) complexes (P-P)Ni(2,4,6-C6H2F3)2 containing either MeOBiPhep (3a) or a macrocyclic ... Full text Cite

Allosteric control of olefin isomerization kinetics via remote metal binding and its mechanochemical analysis.

Journal Article Nature communications · August 2023 Allosteric control of reaction thermodynamics is well understood, but the mechanisms by which changes in local geometries of receptor sites lower activation reaction barriers in electronically uncoupled, remote reaction moieties remain relatively unexplore ... Full text Cite

Facile mechanochemical cycloreversion of polymer cross-linkers enhances tear resistance.

Journal Article Science (New York, N.Y.) · June 2023 The mechanical properties of covalent polymer networks often arise from the permanent end-linking or cross-linking of polymer strands, and molecular linkers that break more easily would likely produce materials that require less energy to tear. We report t ... Full text Cite

Synthesis and Ring-Opening Metathesis Polymerization of a Strained trans-Silacycloheptene and Single-Molecule Mechanics of Its Polymer.

Journal Article Journal of the American Chemical Society · May 2023 The cis- and trans-isomers of a silacycloheptene were selectively synthesized by the alkylation of a silyl dianion, a novel approach to strained cycloalkenes. The trans-silacycloheptene (trans-SiCH) was significantly more strain ... Full text Cite

Contribution of Unbroken Strands to the Fracture of Polymer Networks

Journal Article Macromolecules · March 28, 2023 We present a modified Lake-Thomas theory that accounts for the molecular details of network connectivity upon crack propagation in polymer networks. This theory includes not only the energy stored in the breaking network strands (bridging strands) but also ... Full text Cite

An injectable PEG-like conjugate forms a subcutaneous depot and enables sustained delivery of a peptide drug.

Journal Article Biomaterials · March 2023 Many biologics have a short plasma half-life, and their conjugation to polyethylene glycol (PEG) is commonly used to solve this problem. However, the improvement in the plasma half-life of PEGylated drugs' is at an asymptote because the development of bran ... Full text Link to item Cite

Strain-triggered acidification in a double-network hydrogel enabled by multi-functional transduction of molecular mechanochemistry.

Journal Article Materials horizons · February 2023 Recent work has demonstrated that force-triggered mechanochemical reactions within a polymeric material are capable of inducing measurable changes in macroscopic material properties, but examples of bulk property changes without irreversible changes in sha ... Full text Cite

Concluding remarks: Fundamentals, applications and future of mechanochemistry.

Journal Article Faraday discussions · January 2023 This paper provides a summary of the Faraday Discussions meeting on "Mechanochemistry: fundamentals, applications, and future" in the context of broad themes whose exploration might contribute to a unified framework of mechanochemical phenomena. ... Full text Cite

Covalent Mechanochemistry and Contemporary Polymer Network Chemistry: A Marriage in the Making.

Journal Article Journal of the American Chemical Society · January 2023 Over the past 20 years, the field of polymer mechanochemistry has amassed a toolbox of mechanophores that translate mechanical energy into a variety of functional responses ranging from color change to small-molecule release. These productive chemical chan ... Full text Cite

Effect of strand molecular length on mechanochemical transduction in elastomers probed with uniform force sensors

Journal Article Aiche Annual Meeting Conference Proceedings · January 1, 2023 The mechanical properties of a polymer network reflect the collective behavior of all of the constituent strands within the network. These strands comprise a distribution of states, and a central question is how the deformation and tension experienced by a ... Full text Cite

Linear and multivalent PEGylation of the tobacco mosaic virus and the effects on its biological properties

Journal Article Frontiers in Virology · January 1, 2023 Plant virus-based nanoparticles (VNPs) offer a bioinspired approach to the delivery of drugs and imaging agents. The chemical addressability, biocompatibility, and scalable manufacturability of VNPs make them a promising alternative to synthetic delivery p ... Full text Cite

Scale up and industrial implementation: general discussion.

Journal Article Faraday discussions · January 2023 Full text Cite

Shear processes and polymer mechanochemistry: general discussion.

Journal Article Faraday discussions · January 2023 Full text Cite

Advances in synthesis: general discussion.

Journal Article Faraday discussions · January 2023 Full text Cite

Kinetics and basic understanding: general discussion.

Journal Article Faraday discussions · January 2023 Full text Cite

Mechanochemistry of Cubane.

Journal Article Journal of the American Chemical Society · December 2022 We report the mechanochemical reactivity of the highly strained pentacyclic hydrocarbon cubane. The mechanical reactivity of cubane is explored for three regioisomers with 1,2-, 1,3-, and 1,4-substituted pulling attachments. Whereas all compounds can be ac ... Full text Cite

Force-Modulated Selectivity of the Rhodium-Catalyzed Hydroformylation of 1-Alkenes

Journal Article ACS Catalysis · November 18, 2022 Here we quantify the regio- chemo-, and enantioselectivity of the hydroformylation of 1-alkenes catalyzed by Rh(I) complexes containing chiral macrocyclic biaryl bis(phosphine) ligands as a function of mechanical force applied to the biaryl backbone of the ... Full text Cite

Relaxation dynamics of supramolecular polymer networks with mixed cross-linkers

Journal Article Journal of Rheology · November 1, 2022 The linear rheological properties of supramolecular polymer networks formed by mixtures of two different bis-Pd(II) cross-linkers with poly(4-vinylpyridine) in dimethyl sulfoxide are examined. The changes in storage and loss moduli of the networks with mix ... Full text Cite

Extending BigSMILES to non-covalent bonds in supramolecular polymer assemblies.

Journal Article Chemical science · October 2022 As a machine-recognizable representation of polymer connectivity, BigSMILES line notation extends SMILES from deterministic to stochastic structures. The same framework that allows BigSMILES to accommodate stochastic covalent connectivity can be extended t ... Full text Cite

Pulling Outward but Reacting Inward: Mechanically Induced Symmetry-Allowed Reactions of cis - And trans -Diester-Substituted Dichlorocyclopropanes

Journal Article Synlett · June 1, 2022 The mechanically induced symmetry-allowed disrotatory ring openings of cis- and trans-gem-dichlorocyclopropane (gDCC) diesters are demonstrated through sonication and single-molecule force spectroscopy (SMFS) studies. In contrast to the previously reported ... Full text Cite

Discovery of the Xenon-Protein Interactome Using Large-Scale Measurements of Protein Folding and Stability.

Journal Article Journal of the American Chemical Society · March 2022 The intermolecular interactions of noble gases in biological systems are associated with numerous biochemical responses, including apoptosis, inflammation, anesthesia, analgesia, and neuroprotection. The molecular modes of action underlying these responses ... Full text Cite

Toughening hydrogels through force-triggered chemical reactions that lengthen polymer strands.

Journal Article Science (New York, N.Y.) · October 2021 The utility and lifetime of materials made from polymer networks, including hydrogels, depend on their capacity to stretch and resist tearing. In gels and elastomers, those mechanical properties are often limited by the covalent chemical structure of the p ... Full text Cite

Mechanochemistry of Cationic Cobaltocenium Mechanophore.

Journal Article Journal of the American Chemical Society · August 2021 Recent research on the mechanochemistry of metallocene mechanophores has shed light on the force-responsiveness of these thermally and chemically stable organometallic compounds. In this work, we report a combination of experimental and computational studi ... Full text Cite

Understanding the Mechanochemistry of Ladder-Type Cyclobutane Mechanophores by Single Molecule Force Spectroscopy.

Journal Article Journal of the American Chemical Society · August 2021 We have recently reported a series of ladder-type cyclobutane mechanophores, polymers of which can transform from nonconjugated structures to conjugated structures and change many properties at once. These multicyclic mechanophores, namely, exo-ladd ... Full text Cite

Force-modulated reductive elimination from platinum(ii) diaryl complexes.

Journal Article Chemical science · August 2021 Coupled mechanical forces are known to drive a range of covalent chemical reactions, but the effect of mechanical force applied to a spectator ligand on transition metal reactivity is relatively unexplored. Here we quantify the rate of C(sp2)-C( ... Full text Cite

Single-Event Spectroscopy and Unravelling Kinetics of Covalent Domains Based on Cyclobutane Mechanophores.

Journal Article Journal of the American Chemical Society · April 2021 Mechanochemical reactions that lead to an increase in polymer contour length have the potential to serve as covalent synthetic mimics of the mechanical unfolding of noncovalent "stored length" domains in structural proteins. Here we report the force-depend ... Full text Cite

Molecular Characterization of Polymer Networks.

Journal Article Chemical reviews · April 2021 Polymer networks are complex systems consisting of molecular components. Whereas the properties of the individual components are typically well understood by most chemists, translating that chemical insight into polymer networks themselves is limited by th ... Full text Cite

PolyDAT: A Generic Data Schema for Polymer Characterization.

Journal Article Journal of chemical information and modeling · March 2021 Polymers are stochastic materials that represent distributions of different molecules. In general, to quantify the distribution, polymer researchers rely on a series of chemical characterizations that each reveal partial information on the distribution. Ho ... Full text Cite

Substituent Effects in Mechanochemical Allowed and Forbidden Cyclobutene Ring-Opening Reactions.

Journal Article Journal of the American Chemical Society · March 2021 Woodward and Hoffman once jested that a very powerful Maxwell demon could seize a molecule of cyclobutene at its methylene groups and tear it open in a disrotatory fashion to obtain butadiene (Woodward, R. B.; Hoffmann, R. The Conservation of Orbital Symme ... Full text Cite

Mechanism Dictates Mechanics: A Molecular Substituent Effect in the Macroscopic Fracture of a Covalent Polymer Network.

Journal Article Journal of the American Chemical Society · March 2021 The fracture of rubbery polymer networks involves a series of molecular events, beginning with conformational changes along the polymer backbone and culminating with a chain scission reaction. Here, we report covalent polymer gels in which the macroscopic ... Full text Cite

Single-Molecule Activation and Quantification of Mechanically Triggered Palladium-Carbene Bond Dissociation.

Journal Article Journal of the American Chemical Society · February 2021 Metal-complexed N-heterocyclic carbene (NHC) mechanophores are latent reactants and catalysts for a range of mechanically driven chemical responses, but mechanochemical scission of the metal-NHC bond has not been experimentally characterized. Here we repor ... Full text Cite

Molecular Damage Detection in an Elastomer Nanocomposite with a Coumarin Dimer Mechanophore.

Journal Article Macromolecular rapid communications · January 2021 Molecular force probes that generate optical responses to critical levels of mechanical stress (mechanochromophores) are increasingly attractive tools for identifying molecular sites that are most prone to failure. Here, a coumarin dimer mechanophore whose ... Full text Cite

Onset of Mechanochromic Response in the High Strain Rate Uniaxial Compression of Spiropyran Embedded Silicone Elastomers.

Journal Article Macromolecular rapid communications · January 2021 Featured Publication The molecular processes that accompany dynamic mechanical response to large deformations at high strain rate (≈1000 s-1 or higher) underlie the early stages of damage in materials, but understanding of material response in this regime is typical ... Full text Cite

The role of polymer mechanochemistry in responsive materials and additive manufacturing

Journal Article Nature Reviews Materials · January 1, 2021 The use of mechanical forces to chemically transform polymers dates back decades. In recent years, the use of mechanochemistry to direct constructive transformations in polymers has resulted in a range of engineered molecular responses that span optical, m ... Full text Cite

Distal conformational locks on ferrocene mechanophores guide reaction pathways for increased mechanochemical reactivity.

Journal Article Nature chemistry · January 2021 Mechanophores can be used to produce strain-dependent covalent chemical responses in polymeric materials, including stress strengthening, stress sensing and network remodelling. In general, it is desirable for mechanophores to be inert in the absence of fo ... Full text Cite

Mechanochemical Regulation of Oxidative Addition to a Palladium(0) Bisphosphine Complex.

Journal Article Journal of the American Chemical Society · October 2020 Here, we report the effect of force applied to the biaryl backbone of a bisphosphine ligand on the rate of oxidative addition of bromobenzene to a ligand-coordinated palladium center. Local compressive and tensile forces on the order of 100 pN were generat ... Full text Cite

Enhanced polymer mechanical degradation through mechanochemically unveiled lactonization.

Journal Article Nature communications · October 2020 Featured Publication The mechanical degradation of polymers is typically limited to a single chain scission per triggering chain stretching event, and the loss of stress transfer that results from the scission limits the extent of degradation that can be achieved. Here, we rep ... Full text Cite

Oxidative regulation of the mechanical strength of a C-S bond.

Journal Article Chemical science · September 2020 Featured Publication The mechanical strength of individual polymer chains is believed to underlie a number of performance metrics in bulk materials, including adhesion and fracture toughness. Methods by which the intrinsic molecular strength of the constituents of a given poly ... Full text Cite

Data from: Enhanced polymer mechanical degradation through mechanochemically unveiled lactonization

Dataset · April 22, 2020 The mechanical degradation of polymers is typically limited to a single chain scission per triggering chain stretching event, and the loss of stress transfer that results from the scission limits the extent of degradation that can be achieved. Here, we rep ... Full text Cite

Photoswitchable Sol-Gel Transitions and Catalysis Mediated by Polymer Networks with Coumarin-Decorated Cu24 L24 Metal-Organic Cages as Junctions.

Journal Article Angewandte Chemie (International ed. in English) · February 2020 Photoresponsive materials that change in response to light have been studied for a range of applications. These materials are often metastable during irradiation, returning to their pre-irradiated state after removal of the light source. Herein, we report ... Full text Cite

Mechanically Gated Degradable Polymers.

Journal Article Journal of the American Chemical Society · February 2020 Degradable polymers are desirable for the replacement of conventional organic polymers that persist in the environment, but they often suffer from the unintentional scission of the degradable functionalities on the polymer backbone, which diminishes polyme ... Full text Cite

A Latent Mechanoacid for Time-Stamped Mechanochromism and Chemical Signaling in Polymeric Materials.

Journal Article Journal of the American Chemical Society · January 2020 Mechanically coupled proton transduction offers potential for stress-responsive polymeric materials whose properties can be switched via acid-triggered coloration, polymerization/cross-linking, or degradation. The utility of currently available mechanoacid ... Full text Cite

Correction: Empowering mechanochemistry with multi-mechanophore polymer architectures (Polymer Chemistry (2018) 9 (3583-3593) DOI: 10.1039/C8PY00720A)

Journal Article Polymer Chemistry · December 21, 2019 The authors apologise for an incorrect structure that was presented in Fig. 10. During the preparation of Fig. 10, the authors included unlabeled bonds that indicated vinylic methyl groups instead of hydrogen atoms on the ladderene compounds. The corrected ... Full text Cite

Mechanochromic composite elastomers for additive manufacturing and low strain mechanophore activation

Journal Article Polymer Chemistry · November 28, 2019 Herein, we report a strategy for additive manufacturing of a mechanochemically active silicone ink primarily composed of PDMS microbeads. Extruded, stable structures of cured microbeads were held together with a "bridging material" comprising uncured PDMS ... Full text Cite

High Mechanophore Content, Stress-Relieving Copolymers Synthesized via RAFT Polymerization

Journal Article Macromolecules · November 26, 2019 We report the mechanochemical activity of copolymers formed through the radical addition polymerization of cyclobutene carboxylates that are fused to larger rings. The fused ring repeats act as stored-length mechanophores along the polymer backbone, and so ... Full text Cite

Stereochemical effects on the mechanochemical scission of furan-maleimide Diels-Alder adducts.

Journal Article Chemical communications (Cambridge, England) · October 2019 Clarifying the correlation between the chemical structure of mechanophores and their mechanical reactivity informs the design of mechanochemical systems. One specific correlation that has received much recent attention is that between stereoisomerism and m ... Full text Cite

Strain-Dependent Kinetics in the Cis-to-Trans Isomerization of Azobenzene in Bulk Elastomers.

Journal Article The journal of physical chemistry. B · October 2019 The cis-to-trans isomerization of azobenzene is accelerated in a bulk PDMS elastomer under uniaxial tension. The kinetics are cleanly described by a single-exponential first-order process (k = 2.7 × 10-5 s-1) in the absence of ... Full text Cite

BigSMILES: A Structurally-Based Line Notation for Describing Macromolecules.

Journal Article ACS central science · September 2019 Having a compact yet robust structurally based identifier or representation system is a key enabling factor for efficient sharing and dissemination of research results within the chemistry community, and such systems lay down the essential foundations for ... Full text Open Access Cite

Mechanochemical Ring-Opening of Allylic Epoxides

Journal Article Macromolecules · August 27, 2019 Recent successes in covalent polymer mechanochemistry might more easily be translated to stress-responsive bulk materials if easily scalable and minimalist mechanophores were identified. Epoxides represent attractive modifications of unsaturated polymer ba ... Full text Cite

Dynamic Memory Effects in the Mechanochemistry of Cyclic Polymers.

Journal Article Journal of the American Chemical Society · July 2019 Cyclic polymers containing multiple gem-dichlorocyclopropane (gDCC) mechanophores along their backbone were prepared using ring expansion metathesis polymerization. The mechanochemistry of the cyclic polymers was investigated using pulsed ult ... Full text Cite

A Hierarchical Nanoparticle-in-Micropore Architecture for Enhanced Mechanosensitivity and Stretchability in Mechanochromic Electronic Skins.

Journal Article Advanced materials (Deerfield Beach, Fla.) · June 2019 Biological tissues are multiresponsive and functional, and similar properties might be possible in synthetic systems by merging responsive polymers with hierarchical soft architectures. For example, mechanochromic polymers have applications in force-respon ... Full text Cite

Generalizing metallocene mechanochemistry to ruthenocene mechanophores.

Journal Article Chemical science · May 2019 Recent reports have shown that ferrocene displays an unexpected combination of force-free stability and mechanochemical activity, as it acts as the preferred site of chain scission along the backbone of highly extended polymer chains. This observation rais ... Full text Cite

Quantitative Adjustment to the Molecular Energy Parameter in the Lake-Thomas Theory of Polymer Fracture Energy

Journal Article Macromolecules · April 9, 2019 We present a conceptual framework for adding molecular details of chain extension and force-coupled bond dissociation to the Lake-Thomas model of tear energy in rubbery crack propagation. Incorporating data reported from single-molecule force spectroscopy ... Full text Cite

Mechanical generation of isocyanate by mechanically induced retro [2 + 2] cycloaddition of a 1,2-diazetidinone mechanophore

Journal Article Organic Chemistry Frontiers · April 7, 2019 The encapsulation of guests in supramolecular capsules has long been used to trap reactive intermediates and enhance or reduce the kinetic stability of reactants, and alter the products of chemical reactions that occur within the capsule interior. In recen ... Full text Cite

'Seeing' Strain in Soft Materials.

Journal Article Molecules (Basel, Switzerland) · February 2019 Several technologies can be used for measuring strains of soft materials under high rate impact conditions. These technologies include high speed tensile test, split Hopkinson pressure bar test, digital image correlation and high speed X-ray imaging. Howev ... Full text Cite

Hydrogels muscle their way into new territory.

Journal Article Science (New York, N.Y.) · February 2019 Full text Cite

Ring-Closing Metathesis and Ring-Opening Metathesis Polymerization toward Main-Chain Ferrocene-Containing Polymers

Journal Article Macromolecules · November 27, 2018 We report the preparation of cyclic ferrocenyl olefins with various substituents and different ring sizes by ring-closing metathesis (RCM). These ferrocene-containing monomers were subject to ring-opening metathesis polymerization (ROMP), leading to main-c ... Full text Cite

Regiochemical Effects on Mechanophore Activation in Bulk Materials.

Journal Article Journal of the American Chemical Society · November 2018 Mechanochromic force probes, including spiropyran derivatives, have proven to be useful in visualizing the stress/strain distribution and fracture behavior in polymeric materials. Here, we report the macroscopic response of silicone elastomers including cr ... Full text Cite

Substituent Effects and Mechanism in a Mechanochemical Reaction.

Journal Article Journal of the American Chemical Society · October 2018 We report the effect of substituents on the force-induced reactivity of a spiropyran mechanophore. Using single molecule force spectroscopy, force-rate behavior was determined for a series of spiropyran derivatives substituted with H, Br, or NO2 ... Full text Cite

Quantitative and Mechanistic Mechanochemistry in Ferrocene Dissociation.

Journal Article ACS macro letters · October 2018 Ferrocene is classically regarded as being highly inert owing to the large dissociation energy of metal-cyclopentadienyl (Cp) bonds. We show that the Fe-Cp bond in ferrocene is the preferential site of mechanochemical scission in the pulsed ultrasonication ... Full text Cite

Mechanochromic Stretchable Electronics.

Journal Article ACS applied materials & interfaces · September 2018 Soft and stretchable electronics are promising for a variety of applications such as wearable electronics, human-machine interfaces, and soft robotics. These devices, which are often encased in elastomeric materials, maintain or adjust their functionality ... Full text Cite

Empowering mechanochemistry with multi-mechanophore polymer architectures

Journal Article Polymer Chemistry · July 14, 2018 The development of multi-mechanophore polymers (MMPs) has empowered new methodologies for observing, quantifying, and exploiting mechanochemical transformations. For example, techniques such as single molecule force spectroscopy and pulsed ultrasound can b ... Full text Cite

Disulfide-centered poly(methyl acrylates): Four different stimuli to cleave a polymer

Journal Article Journal of Polymer Science Part A Polymer Chemistry · July 1, 2018 A series of poly(methyl acrylates) incorporating a disulfide center was subjected to four different stimuli to cleave the SS bond, as the weakest member of the chain. Four polymers with molecular weights in the range of 25–93 kDa were synthesized via Cu-b ... Full text Cite

Solvent-Dependent Light-Induced Structures in Gem-Dichlorocyclopropanated Polybutadiene Solutions.

Journal Article The journal of physical chemistry. B · July 2018 The formation of permanent structures upon mild red laser illumination in transparent polydiene solutions is examined in the case of gem-dichlorocyclopropanated polybutadiene ( gDCC-PB) polymers bearing 15% functional units of the dichlorocyclopropane grou ... Full text Cite

Writing Without Ink: A Mechanically and Photochemically Responsive PDMS Polymer for Science Outreach

Journal Article Journal of Chemical Education · November 14, 2017 An easy-To-implement science outreach demonstration featuring a mechanically and photochemically color-changing polymer is described. The active polymeric material is a filled poly(dimethylsiloxane) (PDMS) elastomer that is covalently functionalized with s ... Full text Cite

Polymer mechanochemistry: Up another rung.

Journal Article Nature chemistry · November 2017 Full text Cite

Combined Constant-Force and Constant-Velocity Single-Molecule Force Spectroscopy of the Conrotatory Ring Opening Reaction of Benzocyclobutene.

Journal Article Chemphyschem : a European journal of chemical physics and physical chemistry · June 2017 Single-molecule force spectroscopy (SMFS) of multi-mechanophore polymers has been used to provide kinetic and mechanistic insights into mechanochemical reactions. Whereas biological systems have benefitted from force clamp spectroscopy, synthetic polymers ... Full text Cite

Large-Area Cross-Aligned Silver Nanowire Electrodes for Flexible, Transparent, and Force-Sensitive Mechanochromic Touch Screens.

Journal Article ACS nano · April 2017 Silver nanowire (AgNW) networks are considered to be promising structures for use as flexible transparent electrodes for various optoelectronic devices. One important application of AgNW transparent electrodes is the flexible touch screens. However, the pe ... Full text Cite

Covalent Bond Scission in the Mullins Effect of a Filled Elastomer: Real-Time Visualization with Mechanoluminescence

Journal Article Advanced Functional Materials · December 27, 2016 Strain-induced light emission from mechanoluminescent cross-linkers in silica-filled poly(dimethylsiloxane) demonstrates that covalent bond scission contributes significantly to irreversible stress-softening upon the initial extension, known as the Mullins ... Full text Cite

Mechanical gating of a mechanochemical reaction cascade.

Journal Article Nature communications · November 2016 Covalent polymer mechanochemistry offers promising opportunities for the control and engineering of reactivity. To date, covalent mechanochemistry has largely been limited to individual reactions, but it also presents potential for intricate reaction syste ... Full text Cite

The Mechanical Strength of a Mechanical Bond: Sonochemical Polymer Mechanochemistry of Poly(catenane) Copolymers.

Journal Article Angewandte Chemie (International ed. in English) · October 2016 Topological molecular connections and structures, including physical entanglements in polymer networks, knots along polymer chains, and rotaxanes in sliding ring gels, have important consequences for the physical properties of polymeric materials. Often th ... Full text Cite

Single-Molecule Observation of a Mechanically Activated Cis-to-Trans Cyclopropane Isomerization.

Journal Article Journal of the American Chemical Society · August 2016 The mechanochemical activation of cis-gem-difluorocyclopropane (cis-gDFC) mechanophore in toluene was characterized with single-molecule force spectroscopy. Unlike previously reported behavior in methyl benzoate (MB), two transitions are observed in the fo ... Full text Cite

Sonication-induced scission of molecular bottlebrushes: Implications of the "hairy" architecture

Journal Article Polymer · February 10, 2016 Polymer bottlebrushes may be viewed as hairy flexible cylinders with a long backbone and a thick corona of densely grafted polymer chains. The corona not only controls the bottlebrush diameter, but also provides an additional drag force. We report the stud ... Full text Cite

Accelerating a Mechanically Driven anti-Woodward-Hoffmann Ring Opening with a Polymer Lever Arm Effect.

Journal Article The Journal of organic chemistry · December 2015 Mechanical forces have previously been used to drive reactions along pathways that violate the orbital symmetry effects captured in the Woodward-Hoffmann rules. Here, we show that a polymer "lever arm effect" can provide a mechanical advantage in accelerat ... Full text Cite

Catch and Release: Orbital Symmetry Guided Reaction Dynamics from a Freed "Tension Trapped Transition State".

Journal Article The Journal of organic chemistry · December 2015 The dynamics of reactions at or in the immediate vicinity of transition states are critical to reaction rates and product distributions, but direct experimental probes of those dynamics are rare. Here, s-trans, s-trans 1,3-diradicaloid transition states ar ... Full text Cite

Mechanochemically Active Soft Robots.

Journal Article ACS applied materials & interfaces · October 2015 The functions of soft robotics are intimately tied to their form-channels and voids defined by an elastomeric superstructure that reversibly stores and releases mechanical energy to change shape, grip objects, and achieve complex motions. Here, we demonstr ... Full text Cite

Mechanistic Insights into the Sonochemical Activation of Multimechanophore Cyclopropanated Polybutadiene Polymers

Journal Article Macromolecules · September 22, 2015 Structure-activity relationships in the mechanochemistry of gem-dichlorocyclopropane (gDCC)-based polymer solutions triggered by pulsed ultrasound are reported. Insights into the flow-induced mechanochemical transformations of gDCC mechanophores into the c ... Full text Cite

Reactivity and Mechanism of a Mechanically Activated anti-Woodward-Hoffmann-DePuy Reaction.

Journal Article Journal of the American Chemical Society · September 2015 Mechanical forces, applied via covalent polymer mechanochemistry, have been used to bias reaction pathways and activate otherwise inaccessible reactions. Here, single-molecule polymer mechanochemistry is used to induce the disrotatory outward ring opening ... Full text Cite

Additive manufacturing of mechanochromic polycaprolactone on entry-level systems

Journal Article Rapid Prototyping Journal · August 17, 2015 Purpose - This paper aims to explore and demonstrate the ability to integrate entry-level additive manufacturing (AM) techniques with responsive polymers capable of mechanical to chemical energy transduction. This integration signifies the merger of AM and ... Full text Cite

Relative Mechanical Strengths of Weak Bonds in Sonochemical Polymer Mechanochemistry.

Journal Article Journal of the American Chemical Society · August 2015 The mechanical strength of scissile chemical bonds plays a role in material failure and in the mechanical activation of latent reactivity, but quantitative measures of mechanical strength are rare. Here, we report the relative mechanical strength of polyme ... Full text Cite

Mechanochemical Strengthening of a Multi-mechanophore Benzocyclobutene Polymer.

Journal Article ACS macro letters · August 2015 The mechanical stresses that materials experience during use can lead to aging and failure. Recent developments in covalent mechanochemistry have provided a mechanism by which those stresses can be channeled into constructive, rather than destructive, resp ... Full text Cite

Mechanics of mechanochemically responsive elastomers

Journal Article Journal of the Mechanics and Physics of Solids · July 25, 2015 Abstract Mechanochemically responsive (MCR) polymers have been synthesized by incorporating mechanophores - molecules whose chemical reactions are triggered by mechanical force - into conventional polymer networks. Deformation of the MCR polymers applies f ... Full text Cite

A coumarin dimer probe of mechanochemical scission efficiency in the sonochemical activation of chain-centered mechanophore polymers.

Journal Article Chemical communications (Cambridge, England) · June 2015 Here we present a coumarin dimer (CD) mechanophore that, when embedded near the mid-chain of poly(methyl acrylate) polymers, activates under pulsed ultrasound conditions to yield coumarin chain-end functional polymers. Quantitative photochemical scission o ... Full text Cite

Force-rate characterization of two spiropyran-based molecular force probes.

Journal Article Journal of the American Chemical Society · May 2015 The mechanically accelerated ring-opening reaction of spiropyran to a colored merocyanine provides a useful method by which to image the molecular scale stress/strain distribution within a polymer, but the magnitude of the forces necessary for activation h ... Full text Cite

Molecular engineering of mechanophore activity for stress-responsive polymeric materials.

Journal Article Chemical science · April 2015 Force reactive functional groups, or mechanophores, have emerged as the basis of a potential strategy for sensing and countering stress-induced material failure. The general utility of this strategy is limited, however, because the levels of mechanophore a ... Full text Open Access Cite

Inducing and quantifying forbidden reactivity with single-molecule polymer mechanochemistry.

Journal Article Nature chemistry · April 2015 Forbidden reactions, such as those that violate orbital symmetry effects as captured in the Woodward-Hoffmann rules, remain an ongoing challenge for experimental characterization, because when the competing allowed pathway is available the reactions are in ... Full text Cite

Extended fatigue life of a catalyst free self-healing acrylic bone cement using microencapsulated 2-octyl cyanoacrylate.

Journal Article Journal of biomedical materials research. Part B, Applied biomaterials · February 2015 The tissue adhesive 2-octyl cyanoacrylate (OCA) was encapsulated in polyurethane microshells and incorporated into bone cement to form a catalyst free, self-healing bone cement comprised of all clinically approved components. The bending strength, modulus, ... Full text Cite

Photomechanical actuation of ligand geometry in enantioselective catalysis.

Journal Article Angewandte Chemie (International ed. in English) · December 2014 A catalyst that couples a photoswitch to the biaryl backbone of a chiral bis(phosphine) ligand, thus allowing photochemical manipulation of ligand geometry without perturbing the electronic structure is reported. The changes in catalyst activity and select ... Full text Cite

A remote stereochemical lever arm effect in polymer mechanochemistry.

Journal Article Journal of the American Chemical Society · October 2014 Molecular mechanisms by which to increase the activity of a mechanophore might provide access to new chemical reactions and enhanced stress-responsive behavior in mechanochemically active polymeric materials. Here, single-molecule force spectroscopy reveal ... Full text Cite

Increasing the maximum achievable strain of a covalent polymer gel through the addition of mechanically invisible cross-links.

Journal Article Advanced materials (Deerfield Beach, Fla.) · September 2014 Hydrogels and organogels made from polymer networks are widely used in biomedical applications and soft, active devices for which the ability to sustain large deformations is required. The strain at which polymer networks fracture is typically improved thr ... Full text Cite

Cephalopod-inspired design of electro-mechano-chemically responsive elastomers for on-demand fluorescent patterning.

Journal Article Nature communications · September 2014 Cephalopods can display dazzling patterns of colours by selectively contracting muscles to reversibly activate chromatophores--pigment-containing cells under their skins. Inspired by this novel colouring strategy found in nature, we design an electro-mecha ... Full text Cite

Screening of hyaluronic acid-poly(ethylene glycol) composite hydrogels to support intervertebral disc cell biosynthesis using artificial neural network analysis.

Journal Article Acta biomaterialia · August 2014 Hyaluronic acid (HA)-poly(ethylene glycol) (PEG) composite hydrogels have been widely studied for both cell delivery and soft tissue regeneration applications. A very broad range of physical and biological properties have been engineered into HA-PEG hydrog ... Full text Cite

Mechanochemical Activation of Covalent Bonds in Polymers with Full and Repeatable Macroscopic Shape Recovery.

Journal Article ACS macro letters · March 2014 Covalent mechanochemistry within bulk polymers typically occurs with irreversible deformation of the parent material. Here we show that embedding mechanophores into an elastomeric poly(dimethylsiloxane) (PDMS) network allows for covalent bond activation un ... Full text Cite

Enhancing covalent mechanochemistry in bulk polymers using electrospun ABA triblock copolymers.

Journal Article Faraday discussions · January 2014 The mechanochemical activation of covalent bonds in bulk polymers is often characterized by low conversions. Here we report that the activation of gem-dibromocyclopropane (gDBC) mechanophores embedded in a poly(1,4-butadiene) (PB) is enhanced when a centra ... Full text Cite

Mechanochemical strengthening of a synthetic polymer in response to typically destructive shear forces.

Journal Article Nature chemistry · September 2013 Featured Publication High shear stresses are known to trigger destructive bond-scission reactions in polymers. Recent work has shown that the same shear forces can be used to accelerate non-destructive reactions in mechanophores along polymer backbones, and it is demonstrated ... Full text Cite

Stress-responsive polymers containing cyclobutane core mechanophores: reactivity and mechanistic insights.

Journal Article Journal of the American Chemical Society · September 2013 A primary goal of covalent mechanochemistry is to develop polymer bound mechanophores that undergo constructive transformations in response to otherwise destructive forces. The [2 + 2] cycloreversion of cyclobutane mechanophores has emerged as a versatile ... Full text Cite

A backbone lever-arm effect enhances polymer mechanochemistry.

Journal Article Nature chemistry · February 2013 Featured Publication Mechanical forces along a polymer backbone can be used to bring about remarkable reactivity in embedded mechanically active functional groups, but little attention has been paid to how a given polymer backbone delivers that force to the reactant. Here, sin ... Full text Cite

Physical and materials applications of pincer complexes

Chapter · January 1, 2013 Pincer complexes have been shown to be widely useful and versatile in organic synthesis and catalysis, but they have also been employed in a wide range of intriguing physical and materials applications. The capacity for selective and directional metal-liga ... Full text Cite

Injectable and photocrosslinkable laminin functionalized biomaterials for intervertebral disc regeneration

Journal Article ASME 2012 Summer Bioengineering Conference Sbc 2012 · December 1, 2012 Full text Cite

High Mechanophore Content Polyester-Acrylate ABA Block Copolymers: Synthesis and Sonochemical Activation.

Journal Article Journal of polymer science. Part B, Polymer physics · September 2012 Full text Cite

Rheological properties of cysteine-containing elastin-like polypeptide solutions and hydrogels.

Journal Article Biomacromolecules · August 2012 The rheological properties of cysteine-containing elastin-like polypeptide (Cys-ELP) solutions and Cys-ELP hydrogels are reported. The Cys-ELP solutions exhibit a surprisingly high apparent viscosity at low shear rate. The high viscosity is attributed to t ... Full text Cite

Bicyclo[3.2.0]heptane mechanophores for the non-scissile and photochemically reversible generation of reactive bis-enones.

Journal Article Journal of the American Chemical Society · August 2012 Force-induced transformations of polymer-bound functionalities have the potential to produce a rich array of stress-responsive behavior. One area of particular interest is the activation of non-scissile mechanophores in which latent reactivity can be unvei ... Full text Cite

Mechanochemistry: A tour of force.

Journal Article Nature · July 2012 Full text Cite

Protein polymer hydrogels by in situ, rapid and reversible self-gelation.

Journal Article Biomaterials · July 2012 Protein-based biomaterials are an important class of materials for applications in biotechnology and medicine. The exquisite control of their composition, stereochemistry, and chain length offers unique opportunities to engineer biofunctionality, biocompat ... Full text Link to item Cite

Tension trapping of carbonyl ylides facilitated by a change in polymer backbone.

Journal Article Journal of the American Chemical Society · June 2012 Epoxidized polybutadiene and epoxidized polynorbornene were subjected to pulsed ultrasound in the presence of small molecules capable of being trapped by carbonyl ylides. When epoxidized polybutadiene was sonicated, there was no observable small molecule a ... Full text Cite

Mechanochemical remodeling of synthetic polymers

Journal Article Polymer · February 28, 2012 In the past five years, the field of covalent polymer mechanochemistry has experienced a renaissance. Once limited to the simple scission of polymer chains, mechanical force can now be used to produce a wide array of productive chemistry. These outcomes ha ... Full text Cite

Microstructure of Copolymers Formed by the Reagentless, Mechanochemical Remodeling of Homopolymers via Pulsed Ultrasound.

Journal Article ACS macro letters · January 2012 The high shear forces generated during the pulsed ultrasound of dilute polymer solutions lead to large tensile forces that are focused near the center of the polymer chain, but quantitative experimental evidence regarding the force distribution is rare. He ... Full text Cite

Mechanically induced scission and subsequent thermal remending of perfluorocyclobutane polymers.

Journal Article Journal of the American Chemical Society · November 2011 Perfluorocyclobutane (PFCB) polymer solutions were subjected to pulsed ultrasound, leading to mechanically induced chain scission and molecular weight degradation. (19)F NMR revealed that the new, mechanically generated end groups are trifluorovinyl ethers ... Full text Cite

B-DNA to zip-DNA: simulating a DNA transition to a novel structure with enhanced charge-transport characteristics.

Journal Article The journal of physical chemistry. A · September 2011 The forced extension of a DNA segment is studied in a series of steered molecular dynamics simulations, employing a broad range of pulling forces. Throughout the entire force range, the formation of a zipper-like (zip-) DNA structure is observed. In that s ... Full text Cite

Strain Hardening and Strain Softening of Reversibly Cross-linked Supramolecular Polymer Networks.

Journal Article Macromolecules · September 2011 The large amplitude oscillatory shear behavior of metallo-supramolecular polymer networks formed by adding bis-Pd(II) cross-linkers to poly(4-vinylpyridine) (PVP) in dimethyl sulfoxide (DMSO) solution is reported. The influence of scanning frequency, disso ... Full text Cite

In situ growth of a thermoresponsive polymer from a genetically engineered elastin-like polypeptide

Journal Article Polymer Chemistry · July 1, 2011 We report the in situ growth of a thermoresponsive dumbbell-like polymer conjugate of a genetically engineered triblock elastin-like polypeptide (tELP). Atom transfer radical polymerization (ATRP) was used to directly grow a PEG-like polymer selectively fr ... Full text Cite

Mechanochemically triggered bond formation in solid-state polymers

Journal Article Journal of Materials Chemistry · June 21, 2011 Polybutadiene was functionalized with dibromo-, dichloro-, and bromochloro-carbene to give gem-dihalocyclopropanated (gDHC) polymers, in which the gDHCs act as mechanically activated functional groups or mechanophores. The polymers were extruded to determi ... Full text Cite

Reactive cross-talk between adjacent tension-trapped transition states.

Journal Article Journal of the American Chemical Society · March 2011 Tension along a polymer chain traps neighboring s-trans/s-trans-1,3-diradicals from the mechanically induced ring opening of gem-difluorocyclopropanes (gDFCs). The diradicals correspond to the transition states of the force-free thermal isomerization react ... Full text Cite

From molecular mechanochemistry to stress-responsive materials

Journal Article Journal of Materials Chemistry · February 14, 2011 Featured Publication Current activity in, and future prospects for, the incorporation of mechanochemically active functional groups ("mechanophores") into polymers is reviewed. This area of research is treated in the context of two categories. The first category is the develop ... Full text Cite

Self-healing biomaterials.

Journal Article Journal of biomedical materials research. Part A · February 2011 The goal of this review is to introduce the biomaterials community to the emerging field of self-healing materials, and also to suggest how one could utilize and modify self-healing approaches to develop new classes of biomaterials. A brief discussion of t ... Full text Cite

Scaling Laws in Supramolecular Polymer Networks.

Journal Article Macromolecules · January 2011 The linear rheological properties of networks formed by adding bis-Pd(II) cross-linkers to poly(4-vinylpyridine) (PVP) solution are examined, and the scaling law relationships between the zero shear viscosity (η(0)) of the networks versus the concentration ... Full text Cite

Molecular stress relief through a force-induced irreversible extension in polymer contour length.

Journal Article Journal of the American Chemical Society · November 2010 Featured Publication Single-molecule force spectroscopy is used to observe the irreversible extension of a gem-dibromocyclopropane (gDBC)-functionalized polybutadiene under tension, a process akin to polymer necking at a single-molecule level. The extension of close to 28% in ... Full text Cite

Trapping a diradical transition state by mechanochemical polymer extension.

Journal Article Science (New York, N.Y.) · August 2010 Featured Publication Transition state structures are central to the rates and outcomes of chemical reactions, but their fleeting existence often leaves their properties to be inferred rather than observed. By treating polybutadiene with a difluorocarbene source, we embedded ge ... Full text Cite

Multiple Dynamic Processes Contribute to the Complex Steady Shear Behavior of Cross-Linked Supramolecular Networks of Semidilute Entangled Polymer Solutions.

Journal Article The journal of physical chemistry letters · June 2010 Molecular theories of shear thickening and shear thinning in associative polymer networks are typically united in that they involve a single kinetic parameter that describes the network -- a relaxation time that is related to the lifetime of the associativ ... Full text Open Access Cite

Breaking down the supramolecular ensemble: Single-molecule studies of the concentration dependence of main-chain supramolecular polymer molecular weight distributions on surfaces

Journal Article Australian Journal of Chemistry · April 19, 2010 Single molecule atomic force microscopy (AFM) studies of oligonucleotide-based supramolecular polymers on surfaces are used to examine the molecular weight distribution of the polymers formed between a functionalized surface and an AFM tip as a function of ... Full text Cite

Mechanism of Shear Thickening in Reversibly Cross-linked Supramolecular Polymer Networks.

Journal Article Macromolecules · April 2010 We report here the nonlinear rheological properties of metallo-supramolecular networks formed by the reversible cross-linking of semi-dilute unentangled solutions of poly(4-vinylpyridine) (PVP) in dimethyl sulfoxide (DMSO). The reversible cross-linkers are ... Full text Open Access Cite

Regenerating titanium ventricular assist device surfaces after gold/palladium coating for scanning electron microscopy.

Journal Article Microsc Res Tech · January 2010 Titanium is one of the most commonly used materials for implantable devices in humans. Scanning electron microscopy (SEM) serves as an important tool for imaging titanium surfaces and analyzing cells and other organic matter adhering to titanium implants. ... Full text Link to item Cite

Anion binding of short, flexible aryl triazole oligomers.

Journal Article The Journal of organic chemistry · December 2009 The flexible, electropositive cavity of linear 1,4-diaryl-1,2,3-triazole oligomers provides a suitable host for complexation of various anions. The binding affinities for various combinations of oligomer and anion were determined by (1)H NMR titrations. Ef ... Full text Cite

Steric and solvation effects in ionic S(N)2 reactions.

Journal Article Journal of the American Chemical Society · November 2009 This paper explores the contribution of solvation to the overall steric effects of S(N)2 reactions observed in solution. The reactions of chloride ion with a series of alkyl chloronitriles, RCH(CN)Cl (R = methyl, ethyl, isopropyl, tert-butyl) were investig ... Full text Cite

gem-Dichlorocyclopropanes as abundant and efficient mechanophores in polybutadiene copolymers under mechanical stress.

Journal Article Journal of the American Chemical Society · August 2009 When gem-dichlorocyclopropane (gDCC) copolymers derived from polybutadiene are subjected to ultrasonication, the gDCCs undergo ring opening to form 2,3-dichloroalkenes. The reactivity is not observed in low-molecular-weight (6.5 kDa) copolymers or side-cha ... Full text Cite

Single-Molecule Force Spectroscopy of DNA-Based Reversible Polymer Bridges: Surface Robustness and Homogeneity.

Journal Article Colloids and surfaces. A, Physicochemical and engineering aspects · August 2009 Single-molecule force spectroscopy, as implemented in an atomic force microscope, provides a rarely-used method by which to monitor dynamic processes that occur near surfaces. Here, a methodology is presented and characterized that facilitates the study of ... Full text Cite

Mechanochemistry: Force probes in a bottle.

Journal Article Nature nanotechnology · May 2009 Full text Cite

From ionic liquids to supramolecular polymers.

Journal Article Angewandte Chemie (International ed. in English) · January 2009 Charging forward: Ionic interactions presented in a multivalent fashion in small-molecule ionic liquids lead to functional polymer-like materials (see picture) that are consistent with the formation of a supramolecular ionic network. For example, the ionic ... Full text Cite

Force Probes in a Bottle

Journal Article Nature Nanotech. · 2009 Link to item Cite

Time and distance dependence of reversible polymer bridging followed by single-molecule force spectroscopy.

Journal Article Langmuir : the ACS journal of surfaces and colloids · May 2008 Polymer bridging between surfaces plays an important role in a range of fundamental processes in the material and life sciences. Bridges formed by main-chain reversible polymers differ from their covalent analogs in that they can dynamically adjust their s ... Full text Cite

Cool as a cucumber.

Journal Article Angewandte Chemie (International ed. in English) · January 2008 Full text Cite

1,2,3-Triazole CH...Cl(-) contacts guide anion binding and concomitant folding in 1,4-diaryl triazole oligomers.

Journal Article Angewandte Chemie (International ed. in English) · January 2008 Featured Publication Full text Cite

A hybrid polymer gel with controlled rates of cross-link rupture and self-repair.

Journal Article Journal of the Royal Society, Interface · April 2007 A family of hybrid polymer gels is described, in which covalent cross-links create a permanent, stiff scaffold onto which reversible metal-ligand coordinative cross-links are added. The reversible metal-ligand interactions are shown to bear mechanical stre ... Full text Cite

Influence of the extent of hybridization on the hydrodynamic radius of DNA-functionalized gold nanoparticles.

Journal Article Langmuir : the ACS journal of surfaces and colloids · February 2007 A combination of fluorescence spectroscopy and dynamic laser light scattering is used to investigate the relationship between the extent of hybridization on the surface of DNA-functionalized gold nanoparticles and the hydrodynamic radius (Rh) of the nanopa ... Full text Cite

Physical organic chemistry of supramolecular polymers.

Journal Article Langmuir : the ACS journal of surfaces and colloids · February 2007 Featured Publication Unlike the case of traditional covalent polymers, the entanglements that determine properties of supramolecular polymers are defined by very specific, intermolecular interactions. Recent work using modular molecular platforms to probe the mechanisms underl ... Full text Cite

Chemoresponsive viscosity switching of a metallo-supramolecular polymer network near the percolation threshold

Journal Article Journal of Materials Chemistry · January 1, 2007 The precise manipulation of network percolation, combined with the previously reported effects of the kinetics of cross-linking interactions, provide a mechanism by which to optimize the stimulus-responsive mechanical properties of supramolecular gels. Spe ... Full text Cite

Thermodynamics of pyridine coordination in 1,4-phenylene bridged bimetallic (Pd, Pt) complexes containing two N,C,N' motifs, 1,4-M2-[C6(CH2NR2)4-2,3,5,6].

Journal Article Inorganic chemistry · December 2006 The thermodynamics of pyridine coordination in 1,4-phenylene-bridged binuclear palladium and platinum organometallic complexes [1,4-(MOTf)2-&{C6(CH2NR2)4-2,3,5,6}] (11, M =Pd, Pt; R =CH3, C2H5, R2 = -(CH2)5-) are measured by 1H NMR in DMSO-d6. The coordina ... Full text Cite

Reversibly cross-linked surface-grafted polymer brushes.

Journal Article Angewandte Chemie (International ed. in English) · November 2006 Full text Cite

Single-molecule force spectroscopy of bimolecular reactions: system homology in the mechanical activation of ligand substitution reactions.

Journal Article Journal of the American Chemical Society · March 2006 Featured Publication The mechanochemistry of the bimolecular nucleophilic substitution of DMSO for substituted pyridines at a square-planar pincer Pd(II) center was investigated using single-molecule force spectroscopy (SMFS). The SMFS data are interpreted in terms of the Bell ... Full text Cite

Rational control of viscoelastic properties in multicomponent associative polymer networks

Journal Article Macromolecules · November 29, 2005 We report here the formation and dynamic mechanical properties of metallo-supramolecular networks formed by mixtures of bis-Pd(II) and Pt(II) cross-linkers with poly(4-vinylpyridine) in DMSO. Precise control over the dynamic mechanical properties of the bu ... Full text Cite

Small-molecule dynamics and mechanisms underlying the macroscopic mechanical properties of coordinatively cross-linked polymer networks.

Journal Article Journal of the American Chemical Society · October 2005 Featured Publication Specific metal-ligand coordination between bis-Pd(II) and Pt(II) organometallic cross-linkers and poly(4-vinylpyridine) in DMSO defines a three-dimensional associative polymer network. Frequency-dependent dynamic mechanical moduli of a series of four diffe ... Full text Cite

Thermodynamics of DNA hybridization on gold nanoparticles.

Journal Article Journal of the American Chemical Society · September 2005 Dynamic light scattering is used as a sensitive probe of hybridization on DNA-functionalized colloidal gold nanoparticles. When a target DNA strand possesses an 8 base "dangling end", duplex formation on the surface of the nanoparticles leads to an increas ... Full text Cite

Strong means slow: dynamic contributions to the bulk mechanical properties of supramolecular networks.

Journal Article Angewandte Chemie (International ed. in English) · April 2005 Full text Cite

Self-assembly and properties of main-chain reversible polymer brushes

Journal Article Advanced Materials · 2005 The compressive and adhesive mechanical properties of self-assembled polymer brushes were investigated using DNA-based modules. The effects of surface anchor density, association strength, and monomer flexibility on the properties were also investigated. R ... Full text Link to item Cite

Enzymatic nanolithography of a self-assembled oligonucleotide monolayer on gold.

Journal Article Journal of the American Chemical Society · April 2004 This paper describes a simple strategy to biochemically manipulate a surface at the nanoscale by enzyme dip-pen nanolithography using an endonuclease (DNase I) that is directly patterned on a self-assembled monolayer presenting a terminal oligonucleotide. ... Full text Cite

Structure and Properties of DNA-Based Reversible Polymers

Journal Article Macromolecules · March 9, 2004 Duplex formation between DNA-based monomers creates linear, polymeric assemblies that resemble larger duplex DNA, but in which the main chain is defined by the reversible base pairing. These monomers provide a reversible polymer platform through which mole ... Full text Cite

Surface-to-surface bridges formed by reversibly assembled polymers.

Journal Article Journal of the American Chemical Society · March 2004 Self-assembled polymers whose main chains are defined by reversible DNA base pairing form bridges between the tip of an atomic force microscope and substrate. The forces associated with the rupture of these assemblies are independent of polymer bridge leng ... Full text Cite

Orthogonal control of dissociation dynamics relative to thermodynamics in a main-chain reversible polymer.

Journal Article Journal of the American Chemical Society · December 2003 Featured Publication A pair of homologous and soluble reversible polymers display nearly identical solution structures but dramatically different dissociation dynamics (1.0 vs ca. 100 s-1) along their main chains. The polymers are formed by organopalladium-pyridine coordinatio ... Full text Cite

Modular, well-behaved reversible polymers from DNA-based monomers

Journal Article Angewandte Chemie International Edition · November 4, 2002 Fundamental studies of reversible polymerizations can be achieved with intrinsically modular oligonucleotide-based monomers (OMs) comprised of oligonucleotide sequences that are covalently linked directly or through a synthetic spacer. The thermodynamics a ... Cite

Modular, well-behaved reversible polymers from DNA-based monomers.

Journal Article Angewandte Chemie (International ed. in English) · November 2002 Full text Cite

An NMR study of the rates of single-molecule exchange in a cylindrical host capsule.

Journal Article Journal of the American Chemical Society · July 2002 Self-assembled cylindrical capsule 1 is reversibly formed from dimerization of two tetraimide resorcinarenes. Studies of guest exchange involving host capsule 1 reveal a mechanistic continuum for exchange that depends on the structure of the guest. Kinetic ... Full text Cite

Molecular encapsulation.

Journal Article Angewandte Chemie (International ed. in English) · May 2002 Louis Kahn, architect of the Salk Institute in LaJolla, said "even a common, ordinary brick wants to be something more than it is". Suppose that were also true of molecules. We know that they can and do aggregate; they give complex structures, and by doing ... Full text Cite

Steric effects and solvent effects in ionic reactions.

Journal Article Science (New York, N.Y.) · March 2002 Rates of SN2 reactions of chloride ion with methyl- and tert-butyl-substituted chloroacetonitrile were measured by using Fourier transform-ion cyclotron resonance spectrometry to follow the isotopic exchange reaction. Barrier heights for these reactions in ... Full text Cite

Chemical amplification with encapsulated reagents.

Journal Article Proceedings of the National Academy of Sciences of the United States of America · March 2002 Autocatalysis and chemical amplification are characteristic properties of living systems, and they give rise to behaviors such as increased sensitivity, responsiveness, and self-replication. Here we report a synthetic system in which a unique form of compa ... Full text Cite

Characterization of reversible polymerization utilizing DNA base pairing

Journal Article American Chemical Society Polymer Preprints Division of Polymer Chemistry · January 1, 2002 Cite

Amplification by compartmentalization.

Journal Article Nature · January 2002 Autocatalysis and chemical amplification are properties of living systems that can lead to increased responsiveness and to self-replication. Here we describe a synthetic system in which a unique form of reagent compartmentalization gives rise to nonlinear ... Full text Cite

Emergent conformational preferences of a self-assembling small molecule: Structure and dynamics in a tetrameric capsule

Journal Article Journal of the American Chemical Society · November 8, 2000 Herein we report the synthesis of a molecule that self-organizes through hydrogen bonds into discrete tetrameric capsular species, encapsulating large polycyclic guest molecules. The unique folded structure of the assembled state is determined by correlati ... Full text Cite

Emergent mechanical properties of self-assembled polymeric capsules.

Journal Article Proceedings of the National Academy of Sciences of the United States of America · November 2000 Synthetic self-assembled systems combine responsiveness and reversibility with the ability to perform chemical tasks such as molecular recognition and catalysis. An unmet challenge is the construction of polymeric materials that, like nature's tubulin, are ... Full text Cite

Detection and mechanistic studies of multicomponent assembly by fluorescence resonance energy transfer

Journal Article Journal of the American Chemical Society · August 23, 2000 The kinetics and thermodynamics of multicomponent assembly in organic solution are investigated using fluorescence resonance energy transfer (FRET). Calix[4]arenes functionalized with ureas on their wider rims dimerize in organic solution, via intermolecul ... Full text Cite

Chiral Guests and Their Ghosts in Reversibly Assembled Hosts

Journal Article Angew. Chem. Int. Ed. Eng. · 2000 Cite

Translational energy dependence and potential energy surfaces of gas phase S(N)2 and addition-elimination reactions

Journal Article Journal of the American Chemical Society · December 22, 1999 The translational energy dependence of several gas-phase S(N)2 and carbonyl addition-elimination reaction rate constants has been measured in an FT-ICR. The relative energy dependences of the reactions are qualitatively consistent with variations in the re ... Full text Cite

Intramolecular microsolvation of S(N)2 transition states

Journal Article Journal of the American Chemical Society · July 21, 1999 Introduction of an ω-substituent (CN, Cl, or OH) onto a primary n- alkyl chloride significantly enhances the rate of S(N)2 chloride exchange in the gas phase. Trends in reactivity suggest that the rate acceleration depends primarily on through-space solvat ... Full text Cite

Guest exchange in an encapsulation complex: a supramolecular substitution reaction.

Journal Article Proceedings of the National Academy of Sciences of the United States of America · July 1999 Encapsulation complexes are reversibly formed assemblies in which small molecule guests are completely surrounded by large molecule hosts. The assemblies are held together by weak intermolecular forces and are dynamic: they form and dissipate on time scale ... Full text Cite

Nonstatistical reactivity in a vibrationally excited S(N)2 intermediate [1]

Journal Article Journal of the American Chemical Society · November 25, 1998 Full text Cite

Gas-phase ionic reactions: dynamics and mechanism of nucleophilic displacements

Journal Article Science (New York, N.Y.) · March 1998 Nucleophilic displacement reactions (the SN2 reaction) of ions in the gas phase are a prototypical reaction system that allows a study of dynamics, mechanisms, and structure-energy relations. This article reviews aspects of the kinetics (especially the app ... Full text Cite

Unimoleciilar dynamics in bimolecular ion-molecule reactions

Journal Article Berichte Der Bunsengesellschaft Physical Chemistry Chemical Physics · December 1, 1997 We have measured the translational energy dependence of a series of chloride exchange reactions in the gas phase. The translational energy dependence varies with the changes in the potential energy surfaces across the series of reactions in a manner that i ... Cite

Phase-shifting acceleration of ions in an ion cyclotron resonance spectrometer: Kinetic energy distribution and reaction dynamics

Journal Article Journal of Physical Chemistry A · June 26, 1997 The kinetic energy distribution of trapped ions in an ion cyclotron resonance spectrometer (ICR) under a periodically phase-reversed rf potential is determined. At the operating pressures typical for the ICR (10-7-10-5 Torr), the ions ... Full text Cite

Perturbed equilibria and statistical energy redistribution in a gas- phase S(N)2 reaction

Journal Article Science · June 6, 1997 The relative translational energy of one set of reactants in the gas- phase equilibrium between chloride ion and chloroacetonitrile 35Cl- + 37ClCH2CN ⇆ 37Cl- + 35ClCH2C ... Full text Cite

Branching ratios in activated systems

Journal Article Journal of Physical Chemistry A · January 2, 1997 Branching between reaction channels in activated systems is often observed to vary with changes in the potential energy surface as Δln(k1/k2) ∝ Δ(ΔE‡1 - ΔE‡2). RRKM calculations demonstrate that in many, but not ... Full text Cite

Intramolecular microsolvation of thermoneutral gas-phase S(N)2 reactions

Journal Article Journal of the American Chemical Society · July 17, 1996 Full text Cite

Surface-Mediated Reactions. 6. Effects of Silica Gel and Alumina on Acid-Catalyzed Reactions

Journal Article Journal of Organic Chemistry · June 1, 1995 Adsorption of a variety of acids to chromatographic silica gel results in substantial enhancement of their catalytic activity–affording easily prepared, environmentally benign heterogeneous acids that are highly effective in mediating a number of processes ... Full text Cite

Stereoselectivity and regioselectivity in Diels-Alder reactions studied by intermolecular perturbation theory

Journal Article Journal of the Chemical Society Faraday Transactions · December 1, 1994 Diels-Alder reactions of ethene, acrolein and acrylonitrile with butadiene and its 1-methyl, 2-methyl and 2-cyano derivatives have been studied by self-consistent field intermolecular perturbation theory. The procedure is successful in reproducing the ster ... Full text Cite

Surface-Mediated Reactions. 3. Hydrohalogenation of Alkenes

Journal Article Journal of the American Chemical Society · April 1, 1993 Appropriately prepared silica gel and alumina have been found to mediate the addition of HCl, HBr, and HI to alkenes. The technique has been rendered even more convenient by the use of various organic and inorganic halides that undergo hydrolysis in the pr ... Full text Cite

Surface-Mediated Reactions. 1. Hydrohalogenation of Alkenes and Alkynes

Journal Article Journal of the American Chemical Society · January 1, 1990 Full text Cite