Synthesis and cluster structure distortions of biscarborane dithiol, thioether, and disulfide.

The synthesis and structural characterization of the first sulfur-containing derivatives of the C,C-biscarborane {-CB} cluster - thiol, thioether, and disulfide - are reported. The biscarboranyl dithiol (1-HS-CBH) exhibits an exceedingly long intracluster carbon-carbon bond length of 1.858(3) Å, which is attributed to the extensive interaction between the lone pairs of the thiol groups and the unoccupied molecular orbital of the carborane cluster.