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A Molecular Approach to Self‐Assembly of Trimethylsilylacetylene Derivatives on Gold
Author(s) -
Katsonis Nathalie,
Marchenko Alexandr,
Taillemite Sébastien,
Fichou Denis,
Chouraqui Gaëlle,
Aubert Corinne,
Malacria Max
Publication year - 2003
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200204682
Subject(s) - monolayer , scanning tunneling microscope , molecule , self assembly , triple bond , chemistry , crystallography , methyl group , nanotechnology , silanes , atom (system on chip) , molecular self assembly , stereochemistry , materials science , double bond , group (periodic table) , polymer chemistry , organic chemistry , silane , computer science , embedded system
We recently discovered that a linear multifunctional trimethylsilylacetylene (TMSA) compound forms long‐range and highly stable self‐assembled monolayers (SAMs) on reconstructed Au(111). To better understand the interactions governing self‐assembly in this new system, we synthesized a series of homologue organosilanes and performed scanning tunneling microscopy (STM) measurements at the Au(111)/ n ‐tetradecane interface. The four TMSA‐terminated linear silanes that we synthesized self‐assemble in similar ways on gold, with the molecules standing upright on the surface. In contrast, compounds with a slightly modified terminal group but the same polyunsaturated linear chain above the TMSA head do not self‐assemble. In particular, substituting a methyl group of TMSA with a more bulky one prevents self‐assembly. Removing the CC triple bond of TMSA or substituting the Si atom by a C atom also hinders self‐assembly. Finally, substituting one methyl group of TMSA by a hydrogen atom induces self‐assembly but in a different geometry, with the molecules lying flat on the gold surface in a quasi‐epitaxy mode. Our molecular approach demonstrates the key role played by the TMSA head in self‐assembly, its origin being twofold: 1) the TMSA layers are commensurate to the Au(111) adlattice along the 〈112〉 direction, and 2) the CC triple bond of TMSA activates the Si atom and induces the creation of a surface SiAu chemical bond. The highly stable TMSA‐based SAMs appear then as promising materials for applications in surface modification.