Zwitterionic dithiocarboxylates derived from N-heterocyclic carbenes: coordination to gold surfaces

Citation

Siemeling, Ulrich; Memczak, Henry; Bruhn, Clemens; Vogel, Florian; Träger, Frank; Baio, Joe E.; & Weidner, Tobias (2012). Zwitterionic dithiocarboxylates derived from N-heterocyclic carbenes: coordination to gold surfaces. Dalton transactions (Cambridge, England: 2003), 41(10), 2986-2994.

Abstract

The zwitterionic dithiocarboxylates 1(+)-CS(2)(-)-4(+)-CS(2)(-) were prepared by reacting the corresponding N-heterocyclic carbenes 1,3-bis(2,6-diisoproylphenyl)imidazol-2-ylidene (1), 1,3-diisopropylimidazol-2-ylidene (2), 1,3-dibenzylimidazol-2-ylidene (3) and 1,3-diethylbenzimidazol-2-ylidene (4) with CS(2). In the latter two cases, the corresponding N-heterocylic carbene was generated in situ. Compounds 2(+)-CS(2)(-)-4(+)-CS(2)(-) were structurally characterised by single-crystal X-ray diffraction studies. The chemisorption of these zwitterionic dithiocarboxylates on solid gold substrates was investigated in situ and in real time by optical second harmonic generation (SHG). The resulting thin films were exemplarily characterised by near-edge X-ray absorption fine structure (NEXAFS) spectroscopy and X-ray photoelectron spectroscopy (XPS) in the case of 1(+)-CS(2)(-) and 2(+)-CS(2)(-), revealing the formation of almost contamination-free self-assembled monolayers, which exhibit a remarkable degree of orientational order.

Keyword(s)

Carboxylic Acids
Crystallography, X-Ray
gold
Heterocyclic Compounds
Ligands
Methane
Optical Processes
Oxidation-Reduction
Surface Properties

Reference Type

Journal Article

Secondary Title

Dalton transactions (Cambridge, England: 2003)

Author(s)

Siemeling, Ulrich
Memczak, Henry
Bruhn, Clemens
Vogel, Florian
Träger, Frank
Baio, Joe E.
Weidner, Tobias

Year Published

2012

Date Published

1331683200

Volume Number

41

Issue Number

10

Pages

2986-2994

ISSN/ISBN

1477-9234

DOI

Zwitterionic dithiocarboxylates derived from N-heterocyclic carbenes10.1039/c2dt11976e