Dismutation of Tricyanoboryllead Compounds: The Homoleptic Tetrakis(tricyanoboryl)plumbate Tetraanion

摘要

Abstract A series of unprecedently air‐stable (tricyanoboryl)plumbate anions was obtained by the reaction of the boron‐centered nucleophile B(CN)32− with triorganyllead halides. Salts of the anions R3PbB(CN)3− (R=Ph, Et) were isolated and found to be stable in air at room temperature. In the case of Me3PbHal (Hal=Cl, Br), a mixture of the anions Me4−nPb{B(CN)3}nn− (n=1, 2) was obtained. The Et3PbB(CN)3− ion undergoes stepwise dismutation in aqueous solution to yield the plumbate anions Et4−nPb{B(CN)3}nn− (n=1–4) and PbEt4 as by‐product. The reaction rate increases with decreasing pH value of the aqueous solution or by bubbling O2 through the reaction mixture. Adjustment of the conditions allowed the selective formation and isolation of salts of all anions of the series Et4−nPb{B(CN)3}nn− (n=2–4) including the homoleptic tetraanion Pb{B(CN)3}44−.