Predicting Dinitrogen Activation by Carborane-Based Frustrated Lewis Pairs

Activation of atmospherically abundant dinitrogen (N2) under mild conditions has been a great challenge in chemistry for decades because of the significantly strong N≡N triple bond. The traditional strategy of N2 activation was mainly limited to metallic species until the ground-breaking achievement of N2 activation by two-coordinated borylenes was achieved experimentally in 2018. On the other hand, carborane derivatives have attracted considerable interest for small-molecule activation. Still, the utilization of carborane derivatives in N2 activation remains elusive.

Unexpected White Phosphorus (P4) Activation Modes with Silylene-Substituted o-Carboranes and Access to an Isolable 1,3-Diphospha-2,4-disilabutadiene

New types of metal-free white phosphorus (P4) activation are reported. While the phosphine-silylene-substituted dicarborane 1, CB-SiP {CB = ortho-C,C´-C2B10H10, Si = PhC(tBuN)2Si, P = P[N(tBu)CH2]2}, activates white phosphorus in a 2:1 molar ratio to yield the P5-chain containing species 2, the analogous bis(silylene)-substituted compound 3, CB-Si2, reacts with P4 in the molar ratio of 2:1 to furnish the first isolable 1,3-diphospha-2,4-disilabutadiene (Si=P-Si=P-containing) compound 4.