STRUCTURE OF [NA2(CH3OH)9][TA6CL12(OCH3)6].3CH3OH

Tri-mu-methanol-bis(trimethanolsodium) dodeca-mu-chloro-hexamethoxy-1KO,2KO,3KO,4KO,5KO,6KO-octahedro-hexatantalate methanol solvate (1/3), [Na2(CH3OH)9][Ta6Cl12(OCH3)6].3CH3OH, M(r) = 2127.82, hexagonal, P6(3)/m, a = 11.696 (1), c = 23.110 (3) angstrom, V = 2738 (1) angstrom 3, Z = 2, D(x) = 2.581 g cm-3, lambda-(Mo K-alpha) = 0.71073 angstrom, mu = 124.65 cm-1, F(000) = 1964, T = 143 K, final R = 0.045, wR = 0.053 for 735 observed reflections with I > 3-sigma-(I). The crystal structure reveals a dimeric cation, [Na2(mu-CH3OH)3(CH3OH)6]2+ with octahedral environment about sodium (Na-O bridging, 2.45 angstrom; Na-O terminal, 2.37 angstrom). The octahedral cluster unit, [Ta6Cl12(OCH3)6]2- exhibits Ta-Ta distances of 2.994 (2) and 2.975 (2) angstrom with Ta-Cl from 2.434 (6) to 2.456 (5) angstrom (all bridging). Six methoxo groups are in terminal positions with a Ta-O distance of 2.04 (2) angstrom. The structure is held together by a network of hydrogen bonds between the cations, cluster anions and solvent (methanol) molecules.