Hydrogen bonding vs. molecule-surface interactions in 2D self-assembly of [C60]fullerenecarboxylic acids.
Nanoscale
; 8(38): 16955-16962, 2016 Sep 29.
Article
em En
| MEDLINE
| ID: mdl-27714083
ABSTRACT
The adsorption of C60-malonic derivatives C61(CO2H)2 and C66(CO2H)12 on Au(111) and a pentafluorobenzenethiol-modified Au substrate (PFBT@Au) has been investigated using scanning tunneling microscopy (STM) at a liquid-solid interface. Monofunctionalized C61(CO2H)2 forms a hexagonal close-packed overlayer on Au(111) and individual aligned dimers on PFBT@Au(111). The difference is attributed to the nature of the substrateC61(CO2H)2 interaction (isotropic π-Au bonding vs. anisotropic PFBTCOOH interactions). Surprisingly, in both cases, the directionality of the COOHCOOH motif is compromised in favor of synergistic van der Waals/H bonding interactions. Such van der Waals contacts are geometrically unfeasible in hexafunctionalized C66(CO2H)12 and its assembly on Au(111) leads to a 2D molecular network controlled exclusively by H bonding. For both molecules, the "free" CO2H groups on the monolayer surface can engage in out-of-plane H bonding interaction resulting in the epitaxial growth of subsequent molecular layers.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Nanoscale
Ano de publicação:
2016
Tipo de documento:
Article