title: Chlorinated hypoelectronic dimetallaborane clusters: synthesis, characterization, and electronic structures of (eta(5)-C5Me5W)2B5H(n)Cl(m) (n = 7, m = 2 and n = 8, m = 1).
abstract: Pyrolysis of (eta(5)-C(5)Me(5)WH(3))B(4)H(8), 1, in the presence of excess BHCl(2) x SMe(2) in toluene at 100 degrees C led to the isolation of (eta(5)-C(5)Me(5)W)(2)B(5)H(9), 2, and B-Cl inserted (eta(5)-C(5)Me(5)W)(2)B(5)H(8)Cl, 3, and (eta(5)-C(5)Me(5)W)(2)B(5)H(7)Cl(2), 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 (1)H, (11)B, (13)C NMR, and the structural types were unequivocally established by crystallographic 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 electrophilic substitution of hydrogens at B-H vertices of metallaborane structures.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Madras, Chennai 600 036, India.
authors.forename: Satyanarayan
authors.initials: S
authors.lastname: Sahoo
authors.forename: K Hari Krishna
authors.initials: KH
authors.lastname: Reddy
authors.forename: Rajendra S
authors.initials: RS
authors.lastname: Dhayal
authors.forename: Shaikh M
authors.initials: SM
authors.lastname: Mobin
authors.forename: V
authors.initials: V
authors.lastname: Ramkumar
authors.forename: E D
authors.initials: ED
authors.lastname: Jemmis
authors.forename: Sundargopal
authors.initials: S
authors.lastname: Ghosh