Carboranedithiols: Building Blocks for Self-Assembled Monolayers on Copper Surfaces

0382471 - ÚACH 2013 RIV US eng J - Journal Article
Baše, Tomáš - Bastl, Zdeněk - Havránek, Vladimír - Macháček, Jan - Langecker, Jens - Malina, Václav
Carboranedithiols: Building Blocks for Self-Assembled Monolayers on Copper Surfaces.
Langmuir. Roč. 28, č. 34 (2012), s. 12518-12526. ISSN 0743-7463
R&D Projects: GA ČR GAP205/10/0348; GA AV ČR KAN100400702
Institutional support: RVO:61388980 ; RVO:61388955 ; RVO:61389005 ; RVO:67985882
Keywords : copper surfaces * carboranethiols * cluster * chemisorption * self-assembled monolayer
Subject RIV: CA - Inorganic Chemistry; CF - Physical ; Theoretical Chemistry (UFCH-W)
Impact factor: 4.187, year: 2012

Two different positional isomers of 1,2-dicarba-closo-dodecaboranedithiols, 1,2-(HS)(2)-1,2-C2B10H10 (1) and 9,12-(HS)2-1,2-C2B10H10 (2), have been investigated as cluster building blocks for self-assembled monolayers (SAMs) on copper surfaces. These two isomers represent a convenient system in which the attachment of SH groups at different positions on the skeleton affects their acidic character and thus also determines their reactivity with a copper surface. Isomer 1 exhibited etching of polycrystalline Cu films, and a detailed investigation of the experimental conditions showed that both the acidic character of SH groups and the presence of oxygen at the copper surface play crucial roles in how the surface reaction proceeds: whether toward a self-assembled monolayer or toward copper film etching. We found that each positional isomer requires completely different conditions for the preparation of a SAM on copper surfaces Both isomers exhibited high capacity to remove oxygen atoms from the surface copper(I) oxide that forms immediately after the exposure of freshly prepared copper films to ambient atmosphere. Isomer 2 showed suppression of Cu film oxidation. A number of methods including X-ray photoelectron spectroscopy (XPS), X-ray Rutherford back scattering (RBS), proton-induced X-ray emission (PIXE) analysis, atomic force microscopy (AFM), cyclic voltammetry, and contact angle measurements were used to investigate the experimental conditions for the preparation of SAMs of both positional isomers on copper surfaces and to shed light on the interaction between these molecules and a polycrystalline copper surface.
Permanent Link: http://hdl.handle.net/11104/0007196