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Title: Structural Changes in Self-Catalyzed Adsorption of Carbon Monoxide on 1,4-Phenylene Diisocyanide Modified Au(111)

The self-accelerated adsorption of CO on 1,4-phenylene diisocyanide (PDI)-derived oligomers on Au(111) is explored by reflection–absorption infrared spectroscopy and scanning tunneling microscopy. PDI incorporates gold adatoms from the Au(111) surface to form one-dimensional —(Au–PDI)n— chains that can also connect between gold nanoparticles on mica to form a conductive pathway between them. CO adsorption occurs in two stages; it first adsorbs adjacent to the oligomers that move to optimize CO adsorption. Further CO exposure induces PDI decoordination to form Au–PDI adatom complexes thereby causing the conductivity of a PDI-linked gold nanoparticle array on mica to decrease to act as a chemically drive molecular switch. This simple system enables the adsorption process to be explored in detail. DFT calculations reveal that both the —(Au–PDI)n— oligomer chain and the Au–PDI adatom complex are stabilized by coadsorbed CO. A kinetic “foot-in-the-door” model is proposed in which fluctuations in PDI coordination allow CO to diffuse into the gap between gold adatoms to prevent the PDI from reattaching, thereby allowing additional CO to adsorb, to provide kinetic model for allosteric CO adsorption on PDI-covered gold.
Authors:
 [1] ;  [2] ;  [1] ;  [1] ;  [1] ;  [1]
  1. Univ. of Wisconsin, Milwaukee, WI (United States). Dept. of Chemistry and Lab. for Surface Studies
  2. Brookhaven National Lab. (BNL), Upton, NY (United States). Center for Functional Nanomaterials
Publication Date:
OSTI Identifier:
1213390
Report Number(s):
BNL--108285-2015-JA
Journal ID: ISSN 1932-7447; R&D Project: 16083; KC0403020
Grant/Contract Number:
SC00112704
Type:
Accepted Manuscript
Journal Name:
Journal of Physical Chemistry. C
Additional Journal Information:
Journal Volume: 119; Journal Issue: 32; Journal ID: ISSN 1932-7447
Publisher:
American Chemical Society
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE 1,4-phenylene diisocyanide (PDI); Au(111); carbon monoxide; molecular switch; allosteric effects