REDUCTION OF BISCARBORANE - MOLECULAR-STRUCTURES OF [(15-CROWN-5)3NA2](C2B10H11)2 AND [P(C6H5)3CH3]2[MU-9,10-CH-(MU-9',10'-CH-NIDO-7'-CB10H11)-NIDO-7-CB10H11]

The synthesis, characterization, and elucidation of the structures of [(15-crown-5)3Na2](C2B10H11)2 ([(15-crown-5)3Na2](1)) and [P(C6H5)3CH3]2[mu-9,10-CH-(mu-9',10'-CH-nido-7'-CB10H11)-nido-7-CB10H11] ([P(C6H5)3CH3]2(2)) are described. A comparison is made between the solid-state structures of the anion, 1, in [(15-crown-5)3Na2](1) and [P(C6H5)3CH3]2(1). The structure of the cation [(15-crown-5)3Na2]2+, described in detail, represents the first structural characterization of a 3:2 15-crown-5:Na "club sandwich" complex. [(15-crown-5)3Na2](C2B10H11)2 crystallized in the triclinic space group P1BAR with a = 12.411 (1), b = 14.676 (2), and c = 14.988 (2) angstrom, alpha = 101.371 (3), beta = 96.222 (3), and gamma = 91.549 (4)-degrees, V = 2657 angstrom 3, and Z = 2. Data were collected at 128 K on a modified Picker FACS-1 diffractometer using Mo K-alpha radiation, to a maximum 2-theta = 56-degrees, giving 12 832 unique reflections. The structure was solved by direct methods. The final discrepancy indices were R = 0.057 and R(w) = 0.062 for 5012 independent reflections with I > 3-sigma(I). The protonation of the species formed by the reduction of biscarborane by 4 equiv or an excess of sodium naphthalide resulted in the formation of Na2(2). [P(C6H5)3CH3]2(2) crystallized in the monoclinic space group P2(1)/n with a = 11.429 (3), b = 15.075 (4), and c = 16.520 (4) angstrom, beta = 119.648 (8)-degrees, V = 2474 angstrom 3, and Z = 2. Data were collected on a Huber diffractometer (constructed at UCLA) using Mo K-alpha radiation, to a maximum 2-theta = 50-degrees, giving 4368 unique reflections. The structure was solved by direct methods (MULTAN80). The final discrepancy indices were R = 0.070 and R(w) = 0.101 for 3264 independent reflections with I > 3-sigma(I).