New types of products obtained by combining two dinuclear multiply metal-metal bonded species (doublets) to obtain cyclic tetranuclear products (quartets) are reported. One new type consists of pairs of quadruply bonded Mo 2 4+ units united by two µ-X links (X ) H, OH, O) although in the last case oxidation has also occurred so that these are Mo 2 5+ moieties. In these cases, the subunits are Mo 2 (DArF) 3 . The second new type consists of Mo 2 (DArF) 2 subunits linked by four µ-X bridges, where X ) Cl, Br, I. The previously known compound Mo 4 I 8 (PBu n 3 ) 4 has been shown to differ from all previously known Mo 4 X 8 (PR 3 ) 4 molecules (X ) Cl, Br) by retaining two quadruple bonds instead of being a metallacyclobutadiyne, as are the others.

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1,7-(SMe2)2B12H10, 1,12-(SMe2)2B12H10, and [SMe3][B12H11(SMe2)] were prepared and isolated from the self-condensation reaction of BH3·SMe2 in the absence of a solvent. At 150 °C the reaction yields, primarily, two isomers:  1,7-(SMe2)2B12H10, the major component, and 1,12-(SMe2)2B12H10 the minor component, that are separated by thin layer chromatography. Single-crystal X-ray structure determinations were performed for both isomers, confirming the structures inferred from 1H, 11B, and 11B{1H}-11B{1H} (COSY) NMR spectra. Crystal data for 1,7-(SMe2)2B12H10:  trigonal P3221, a = 12.901(10) Å, b = 12.901(10) Å, c = 23.73(2) Å, γ = 120°, Z = 9. Crystal data for 1,12-(SMe2)2B12H10:  orthorhombic Pbca, a = 10.101(2) Å, b = 11.220(2) Å, c = 13.464(2) Å, Z = 4. At 60 °C, the self-condensation of BH3·SMe2 is very slow, but yields [SMe3][B12H11(SMe2)] as the major product. Multinuclear and 2-dimensional NMR spectra are in full accord with the structure determined by X-ray methods. Crystal data for [SMe3][B12H11(SMe2)]·MeCN:  monoclinic P21, a = 8.904(10) Å, b = 9.08(2) Å, c = 12.39(3)Å, β = 93.82°, Z = 2.