open access

https://hdl.handle.net/2115/90168

Identifying Substrate-Dependent Chemical Bonding Nature at Molecule/Metal Interfaces Using Vibrational Sum Frequency Generation Spectroscopy and Theoretical Calculations

英語

2022-07-14

American Chemical Society

Journal of physical chemistry c

126(27)

11298-11309

The effect of metal substrates on the chemical bonding nature at molecule-metal interfaces was investigated for aryl isocyanide molecules with different para-substituents X- C6H4-NC (X = H; NO2 (electron-withdrawing group); OCH3 (electron-donating group)) adsorbed on Au(111) and Ag(111) surfaces by surface-specific vibrational sum frequency generation (VSFG) spectroscopy and periodic density functional theory calculations. Both the experimental VSFG spectra and the anharmonic vibrational spectra from theoretical calculations confirm that the substrate effect acts to increase the NC stretching frequency (blue shift) and that the Au(111) surface shows a larger blue shift than the Ag(111) surface. To analyze the mechanism of this substrate dependence, we performed a natural bond orbital (NBO) analysis extended to periodic systems and found that at the molecule-metal interface, the sigma donation from the molecule to the substrate (strengthening the NC bond) is more pronounced than the pi back-donation (weakening NC bond) and that the effect of sigma donation is stronger for the Au substrate than for the Ag substrate.

学術雑誌論文

Accepted Manuscript

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Physical Chemistry C, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/articlesonrequest/AOR-RQ3WXGRB7HI3JZD2NZUI.

1932-7447