White Phosphorus Reduction and Oligomerization by a Potassium Diamidoalumanyl

Reactions of the potassium alumanyl derivative, [K{Al(SiNDipp)}]2 (SiNDipp = {CH2SiMe2NDipp}2), with white phosphorus result in two electron reduction to provide controlled access to species containing the (P4)2- dianion. Two examples have been crystallographically characterized, a monomeric derivative in which the potassium cation is encapsulated by 18-crown-6 (18-cr-6) and a 1-dimensional polymeric species isolated from diethyl ether solution. Although reactions performed at more elevated temperatures and in the presence of additional equivalents of P4 resulted in similar outcomes, these conditions also result in P4 oligomerization, albeit by as yet unidentified mechanisms. The structures of [{(SiNDipp)AlK(THF)2}2(P6)] and [{(SiNDipp)AlK(toluene)2}2(P16)] have, thus, also been crystallographically characterized and interrogated computationally by quantum chemical (DFT, QTAIM) methods.