Anionic N-Heterocyclic Dicarbene−Borane Binuclear Complexes

The first anionic N-heterocyclic dicarbene−borane binuclear complexes, Li+·[H3B:C{[N(2,6-Pri2C6H3)]2CHC:BH3}]− (V) and Li+(THF)3·[H3B:C{[N(2,6-Pri2C6H3)]2CHC:BEt3}]− (VI), were synthesized by combining BH3·THF with [:C{[N(2,6-Pri2C6H3)]2CHCLi}]n (III) and (THF)2Li:C{[N(2,6-Pri2C6H3)]2CHC(BEt3)} (IV), respectively. X-ray crystal structures of a (V·THF)n polymer, a V·(DME)2 monomer, a (V·DME)2 dimer, and a VI monomer were obtained. The nature of the bonding of V and VI was probed further by computations.