Carboranyl derivatives of mercury and thallium as synthons for boron-substituted carboranes
Carboranyl derivatives of mercury and thallium have been obtained by mercuration and thallation of carbora- nes(l2) in the 9 position of the carborane cage. The substitu- tion of metal atom in boron-mercurated and boron-thallated carboranes allowed a great variety of B(g)-substituted carbo- ranes to be prepared. The previously unknown carboran-9-yl derivatives of nontransition metals, 9-fluoro-, 9-thiocyano-, 9-trifluoroacetoxy-carboranesI bis(carboran-9-y1)diselenides and bis(carboran 9-y1)tellurides as well as the known 9-hyd- roxy-, 9-mercapto- and 9-iodocarboranes were synthesized. In many cases, the reactions occur under radical conditions (photolysis, pyrolysis) to give B(9)-centered radicals which undergo further transformation.