10-VERTEX MONOCARBABORANE CHEMISTRY - SYNTHESIS OF CARBON-SUBSTITUTEDLIGAND DERIVATIVES 1-L-CLOSO-1-CB9H9 AND CRYSTAL AND MOLECULAR-STRUCTURE OF 1-(ME3N)-CLOSO-1-CB9H9

The monocarbaborane ligand derivative (1-(H3N)-closo-1-CB9H9 has been isolated in 75% yield from the reaction between 6-(H3N)-nido-6-CB9H11 and Et3N . BH3 in tetrahydrofuran in the presence of NaBH4. Further re actions involving the exoskeletal H3N group have led to the isolation of the series of related derivatives 1-L-closo-1-CB9H9, where L = Me2S , [H2N](-), Me3NH, or Me3N. Boron-11 and H-1 NMR measurements were con sistent with the proposed structure of all the compounds, with the str ucture of the NMe3 derivative 1-(Me3N)-closo-1-CB9H9 additionally dete rmined by an X-ray diffraction analysis.