ONE-STEP PREPARATION OF DIMETHYL SULFIDE SUBSTITUTED ICOSAHEDRAL BORANES - THE CRYSTAL AND MOLECULAR-STRUCTURES OF 1,7-(SME(2))(2)B12H10, 1,12-(SME(2))(2)B12H10, AND [SME(3)][B12H11(SME(2))]CENTER-DOT-MECN

1,7-(SMe(2))(2)B12H10, 1,12-(SMe(2))(2)B12H10, and [SMe(3)][B12H11(SMe (2))] were prepared and isolated from the self-condensation reaction o f BH3 . SMe(2) in the absence of a solvent. At 150 degrees C the react ion yields, primarily, two isomers: 1,7-(SMe(2))(2)B12H10, the major c omponent, and 1,12-(SMe(2))(2)B12H10 the minor component, that are sep arated by thin layer chromatography. Single-crystal X-ray structure de terminations were performed for both isomers, confirming the structure s inferred from H-1, B-11, and B-11{H-1}-B-11{H-1} (COSY) NMR spectra. Crystal data for 1,7-(SMe(2))(2)B12H10: trigonal P3(2)21, a = 12.901( 10) Angstrom, b = 12.901(10) Angstrom, c = 23.73(2) Angstrom, gamma = 120 degrees, Z = 9. Crystal data for 1,12-(SMe(2))(2)B12H10: orthorhom bic Pbca, a = 10.101(2) Angstrom, b = 11.220(2) Angstrom, c = 13.464(2 ) Angstrom, Z = 4. At 60 degrees C, the self-condensation of BH3 . SMe (2) is very slow, but yields [SMe(3)][B12H11(SMe(2))] as the major pro duct. Multinuclear and 2-dimensional NMR spectra are in full accord wi th the structure determined by X-ray methods. Crystal data for [SMe(3) ][B12H11(SMe(2))]. MeCN: monoclinic P2(1), a = 8.904(10) Angstrom, b = 9.08(2) Angstrom, c = 12.39(3)Angstrom, beta = 93.820, Z = 2.