Conductance of Au/1,4-benzenedicarbothioamide/Au molecular junctions: A proposal for a potential linker

We studied the conductance of Au/1,4-benzenedicarbothioamide (BDTA)/Au junctions at room temperature and measured a single-molecule conductance of BDTA. A carbothioamide (thioamide, – CSNH 2 ) group of this molecule consists of two potential linkers, thioketone and amine groups, and would thus be expected to show high conductance. The experimental single-molecule conductance of BDTA is ( 0.8 – 1.0 ) × 10 - 3 G 0 which roughly compares with that of π -conjugated molecules. We consider that this relatively high conductance of Au/BDTA/Au is due to the homoconjugation of π -orbitals of benzene and sulfur while the amine group is likely to remain as a side group. We also observed that Au/BDTA/Au junctions can exist in multiple configurations of different conductances.