Experimental Evaluation of (L)Au Electron-Donor Ability in Cationic Gold Carbene Complexes.

Published

Journal Article

29 Si NMR spectroscopy was employed to evaluate the electron donor properties of the (L)Au fragments in the cationic gold (β,β-disilyl)vinylidene complexes [(L)Au=C=CSi(Me)2 CH2 CH2 Si(Me)2 ]+ B(C6 F5 )4- [L=P(tBu)2 o-biphenyl or NHC] relative to the p-substituted aryl group in the α-aryl-(β,β-disilyl)vinyl cations [(p-C6 H4 X)-C= CSi(Me)2 CH2 CH2 Si(Me)2 ]+ B(C6 F5 )4- . Similarly, 19 F NMR was employed to evaluate the σ- and π-electron donor properties of the (L)Au fragments in the neutral gold fluorophenyl complexes (L)Au(C6 H4 F) and in the cationic (fluorophenyl)methoxycarbene complexes [(L)AuC(OMe)(C6 H4 F)]+ SbF6- [L=P(tBu)2 o-biphenyl or IPr] relative to the p-substituted aryl group of the protonated monofluorobenzophenones [(p-C6 H4 X)(C6 H4 F)COH]+ OTf- . The results of these studies indicate that relative to p-substituted aryl groups, the gold (L)Au fragments [L=P(tBu)2 o-biphenyl or NHC] are significantly more inductively electron donating and are comparable π-donors and for this reason, the extent of (L)Au→C1 electron donation in gold carbene complexes appears to exceed that provided by a p-(dimethyamino)phenyl group. Furthermore, the [L=P(tBu)2 o-biphenyl]Au fragment is a nominally stronger electron donor than the (IPr)Au fragment, and both are significantly more inductively electron donating than the (PPh3 )Au and [P(OMe)3 ]Au fragments.

Full Text

Duke Authors

Cited Authors

  • Carden, RG; Lam, N; Widenhoefer, RA

Published Date

  • December 2017

Published In

Volume / Issue

  • 23 / 71

Start / End Page

  • 17992 - 18001

PubMed ID

  • 29031001

Pubmed Central ID

  • 29031001

Electronic International Standard Serial Number (EISSN)

  • 1521-3765

International Standard Serial Number (ISSN)

  • 0947-6539

Digital Object Identifier (DOI)

  • 10.1002/chem.201703820

Language

  • eng