Bismuth Coordination Chemistry with Allyl, Alkoxide, Aryloxide, and Tetraphenylborate Ligands and the {[2,6-(Me2NCH2)2C6H3]2Bi}+ Cation

A series of bis(aryl) bismuth compounds containing (N,C,N)-pincer ligands, [2,6-(Me2NCH2)2C6H3]− (Ar′), have been synthesized and structurally characterized to compare the coordination chemistry of Bi3+ with similarly sized lanthanide ions, Ln3+. Treatment of Ar′2BiCl, 1, with ClMg(CH2CHCH2) affords the allyl complex Ar′2Bi(η1-CH2CHCH2), 2, in which only one allyl carbon atom coordinates to bismuth. Complex 1 reacts with KOtBu and KOC6H3Me2-2,6 to yield the alkoxide Ar′2Bi(OtBu), 3, and aryloxide Ar′2Bi(OC6H3Me2-2,6), 4, respectively, but the analogous reaction with the larger KOC6H3tBu2-2,6 forms [Ar′2Bi][OC6H3tBu2-2,6], 6, in which the aryloxide ligand acts as an outer sphere anion. Chloride is removed from 1 by NaBPh4 to form [Ar′2Bi][BPh4], 5, which crystallizes from THF in an unsolvated form with tetraphenylborate as an outer sphere counteranion.