Synthesis, Characterization, and Chemistry of Dimethyl Sulfide Derivatives of closo-B10H102-

Abstract

The reaction of Cs2[B10H10] with DMSO in acid produces the disubstituted 1,10-, 1,6-, and 2,7(8)-isomers of (Me2S)2B10H8 as well as the monosubstituted [(Me2S)B10H9]- anion. Through a modified procedure, the trisubstituted compound 1,10-(Me2S)2-2-(MeS)B10H7 was prepared and characterized. The 1,10-(Me2S)2B10H8 isomer was converted to the enantiomers 2,7-(Me2S)2B10H8 and 2,8-(Me2S)2B10H8 which were separated on a chiral column. The 1,6-(Me2S)2B10H8 isomer was converted to a mixture of 1,10-(Me2S)2B10H8 and 2,3-(Me2S)2B10H8. These polyhedral rearrangements are believed to occur through the diamond-square-diamond mechanism. The 1,6- and 1,10-(Me2S)2B10H8 isomers were reduced with alkali metal in liquid ammonia to produce the dianions [1,6-(MeS)2B10H8]2- and [1,10-(MeS)2B10H8]2-, respectively. Sodium ethanethiolate was used for the reduction of [1-(Me2S)B10H9]- and 1,10-(Me2S)2B10H8 to form [1-(MeS)B10H9]2- and [1-(MeS)-10-(Me2S)B10H8]-, respectively. The structures of 1,10-(Me2S)2B10H8, 1,6-(Me2S)2B10H8, 2,8-(Me2S)2B10H8, 2,3-(Me2S)2B10H8, 1,10-(Me2S)2-2-(MeS)B10H7, [1-(MeS)-10-(Me2S)B10H8]-, and [1,6-(MeS)2B10H8]2- were determined by single-crystal X-ray diffraction analysis.