Anionic N-Heterocyclic Dicarbene-Borane Binuclear Complexes

The first anionic N-heterocyclic dicarbene-borane binuclear complexes, Li+center dot[H3B:C{[N(2,6-(Pr2C6H3)-C-i)](2)CHC:BH3}](-) (V) and Li+-(THF)(3)center dot(H3B:C{[N(2,6-(Pr2C6H3)-C-i)](2)CHC:BEt3)](-) (VI), were synthesized by combining BH3 center dot THF with [:C{[N(2,6-(Pr2C6H3)-C-i)](2)CHCLi}](n) (M) and (THF)(2)Li:C{[N(2,6-(Pr2C6H3)-C-i)](2)CHC(BEt3)} (IV), respectively. X-ray crystal structures of a (V center dot THF)(n) polymer, a V center dot(DME)(2) monomer, a (V center dot DME)(2) dimer, and a VI monomer were obtained. The nature of the bonding of V and was probed further by computations.