Synthesis and structure of halogen derivatives of 9-dimethylsulfonium-7,8-dicarba- nido-undecaborane [9-Me 2S-7,8-C 2B 9H 11

Abstract

Halogenation of 9-dimethylsulfonium-7,8-dicarba- nido-undecaborane [9-SMe 2-7,8-C 2B 9H 11] with N-chlorosuccinimide, bromine and iodine gave the expected corresponding halogen derivatives [9-SMe 2-11-X-7,8-C 2B 9H 10], where X = Cl ( 1), Br ( 2), I ( 3). In the bromination reaction, [9-SMe 2-6-Br-7,8-C 2B 9H 10] ( 4) was isolated as a minor product being the first example of substitution at a “lower” belt of the 7,8-dicarba- nido-undecaborate cage. The use of excess of bromine resulted in dibromo derivative [9-SMe 2-6,11-Br 2-7,8-C 2B 9H 9] ( 5). Structures of the compounds prepared were determined using 11B– 11B COSY NMR spectroscopy (for all halogen derivatives) and single crystal X-ray diffraction (for compounds 2, 3, and 5).