Orientation and bonding of biphenyldimethyldithiol

The molecular orbitals of -biphenyl- -dimethyldithiol (HS–CH 2 –C 6 H 4 –C 6 H 4 –CH 2 –SH) are identified from combined photoemission and inverse photoemission studies and compared with theory for several different surfaces, molecular conformations and molecular orientations. The preferential molecular orientations of biphenyldimethyldithiol, on both Au(111) and polycrystalline Co, are identified from polarization resolved photoemission studies. Two different molecular orientations are adopted by biphenyldimethyldithiol on gold depending on adsorption conditions. Biphenyldimethyldithiol is observed to bond more strongly to cobalt than gold surfaces.