Synthesis and characterization of new 19-vertex macropolyhedral boron hydrides

The new boron hydride anions 10-R-B19H19- (R = H, Thx) were synthesized by the reaction of M-2[B18H20] (M = Na, K) with HBRCl.SMe2 (R = H, Thx) or HBCl2.SMe2 in diethyl ether. The anions are comprised of edge-sharing, nide 10- and 11-vertex cluster fragments, and are characterized by their B-11, B-11{H-1}, and B-11-B-11 COSY NMR spectra. The salt [(Ph3P)(2)N][B19H20].0.5THF crystallized in the triclinic space group P (1) over bar (a = 12.6344(2) Angstrom,b = 13.5978(2) Angstrom,c = 14.1401(2) Angstrom; alpha = 77.402(2)degrees, beta = 81.351(2)degrees, gamma = 73.253(2)degrees). Possible synthetic pathways are discussed. The dianion B19H192- is formed by deprotonation of B19H20- with Proton Sponge (1,8-bis(dimethylamino)naphthalene) in THF, and is identified on the basis of its B-11, B-11{H-1}, and B-11-B-11 COSY NMR spectra.