Oxidation of the [nido-6,9-C2B8H10]2- Anion - An Alternative Source of the 1,6- and 1,10-Dicarba-closo-decaboranes(10)
The oxidation of the [ nido -6,9-C 2 B 8 H 10 ] 2- ( 1 ) dianion with CuCl 2 , is supposed to proceed via an unstable closo -2,6-C 2 B 8 H 10 ( 2 ) intermediate, which is then rearranged into closo -1,6-C 2 B 8 H 10 ( 3 ) (yields 30-35%). The synthesis is accompanied by the formation of the isomeric closo -dicarbaboranes 1,10-C 2 B 8 H 10 ( 4 ) and 1,2-C 2 B 8 H 10 ( 5 ) and the whole procedure can be modified to isolate only isomer 4 (yield 35%). Side products from the synthesis consist of a complex and so far unseparable mixture, in which arachno -4,6-C 2 B 7 H 13 , chloro derivatives closo -C 2 B 8 H 9 Cl, and trimeric compounds of a closo -(C 2 B 8 H 9 ) 2 -C 2 B 8 H 8 formulation were detected by GLC/MS techniques. These findings point to the involvement of a radical-chain mechanism in the reaction.