Fluctuations in biological and bioinspired electron-transfer reactions.

Journal Article (Review;Journal Article)

Central to theories of electron transfer (ET) is the idea that nuclear motion generates a transition state that enables electron flow to proceed, but nuclear motion also induces fluctuations in the donor-acceptor (DA) electronic coupling that is the rate-limiting parameter for nonadiabatic ET. The interplay between the DA energy gap and DA coupling fluctuations is particularly noteworthy in biological ET, where flexible protein and mobile water bridges take center stage. Here, we discuss the critical timescales at play for ET reactions in fluctuating media, highlighting issues of the Condon approximation, average medium versus fluctuation-controlled electron tunneling, gated and solvent relaxation controlled electron transfer, and the influence of inelastic tunneling on electronic coupling pathway interferences. Taken together, one may use this framework to establish principles to describe how macromolecular structure and structural fluctuations influence ET reactions. This framework deepens our understanding of ET chemistry in fluctuating media. Moreover, it provides a unifying perspective for biophysical charge-transfer processes and helps to frame new questions associated with energy harvesting and transduction in fluctuating media.

Full Text

Duke Authors

Cited Authors

  • Skourtis, SS; Waldeck, DH; Beratan, DN

Published Date

  • January 2010

Published In

Volume / Issue

  • 61 /

Start / End Page

  • 461 - 485

PubMed ID

  • 20192814

Pubmed Central ID

  • PMC2883780

Electronic International Standard Serial Number (EISSN)

  • 1545-1593

International Standard Serial Number (ISSN)

  • 0066-426X

Digital Object Identifier (DOI)

  • 10.1146/annurev.physchem.012809.103436


  • eng