TY - JOUR T1 - Decaborane Thiols as Building Blocks for Self-Assembled Monolayers on Metal Surfaces JF - Inorganic Chemistry Y1 - 2012 A1 - Jonathan Bould A1 - Jan Machacek A1 - Michael G S Londesborough A1 - Ramon Macias A1 - John D Kennedy A1 - Zdenek Bastl A1 - Patrik Rupper A1 - Tomas Base AB -

Three nido-decaborane thiol cluster compounds, [1-(HS)-nido-B10H13] 1, [2-(HS)-nido-B10H13] 2, and [1,2-(HS)2-nido-B10H12] 3 have been characterized using NMR spectroscopy, single-crystal X-ray diffraction analysis, and quantum-chemical calculations. In the solid state, 1, 2, and 3 feature weak intermolecular hydrogen bonding between the sulfur atom and the relatively positive bridging hydrogen atoms on the open face of an adjacent cluster. Density functional theory (DFT) calculations show that the value of the interaction energy is approximately proportional to the number of hydrogen atoms involved in the interaction and that these values are consistent with a related bridging-hydrogen atom interaction calculated for a B18H22 C6H6 solvate. Self-assembled monolayers (SAMs) of 1, 2, and 3 on gold and silver surfaces have been prepared and characterized using X-ray photoelectron spectroscopy. The variations in the measured sulfur binding energies, as thiolates on the surface, correlate with the (CC2) calculated atomic charge for the relevant boron vertices and for the associated sulfur substituents for the parent B10H13(SH) compounds. The calculated charges also correlate with the measured and DFT-calculated thiol 1H chemical shifts. Wetting-angle measurements indicate that the hydrophilic open face of the cluster is directed upward from the substrate surface, allowing the bridging hydrogen atoms to exhibit a similar reactivity to that of the bulk compound. Thus, [PtMe2(PMe2Ph)2] reacts with the exposed and acidic B VL - 51 ER -