COOH-terminated SAMs on gold fabricated from an azobenzene derivative with a 1,2-dithiolane headgroup

Abstract

Well-defined and homogeneous, contamination-free self-assembled monolayers (SAMs) were fabricated by the chemisorption of lip-NH- p-C 6H 4-N N- p-C 6H 4-COOH (lip = α-lipoyl) onto gold. This adsorbate species is composed of a 1,2-dithiolane-based headgroup, an azobenzene-based (and hence photochromic) spacer unit and a carboxylic acid functional group. The SAM constituents are covalently attached to the substrate by the bidentate thiolate anchor groups and exhibit a strongly tilted binding configuration.