Chlorinated hypoelectronic dimetallaborane clusters: Synthesis, characterization, and electronic structures of (η-C<inf>5</inf>Me <inf>5</inf>W)<inf>2</inf>B<inf>5</inf>H<inf>n</inf>CI<inf>m</inf>, (n = 7, m = 2 and n = 8, m = 1)

Pyrolysls of (η5-C5Me5WH 3)B4H8,1, In the presence of excess BHCl 2 • SMe2 in toluene at 100 °C led to the Isolation of (η5-C5Me5W)2B 5H9,2, and B-Cl inserted (η5-C 5Me5W)2B5H8Cl, 3, and (η5-C5Me5W)2B5H 7Cl2,4-7 (four isomers). All the chlorinated tungstaboranes were Isolated as red and air and moisture sensitive solids. These new compounds have been characterized in solution by 1H, 11B, 13C NMR, and the structural types were unequivocally established by crystallographlc analysis of compounds 3,4, and 7. Density functional theory (DFT) calculations were carried out on the model molecules of 3-7 to elucidate the actual electronic structures of these chlorinated species. On grounds of DFT calculations we demonstrated the role of transition metals, bridging hydrogens, and the effect of electrophlllc substitution of hydrogens at B-H vertices of metallaborane structures. © 2009 American Chemical Society.