A pentuply-bridging carbonyl group: crystal and molecular structure of a salt of the 1-oxo-2-phenyl-1,2-dicarbadodecaborate(12) anion, [LH]+[O(Ph)C2B10H10]–(L = 1,8-N,N,N′,N′-tetramethylnaphthalenediamine)

Abstract

Deprotonation of the C-hydroxy ortho-carborane 1,2-HO(Ph)C₂B₁₀H₁₀ by 1,8-N,N,N′,N′-tetramethylnaphthalene-diamine gives a salt whose anion, [O(Ph)C₂B₁₀H₁₀]^–, effectively consists of a nido-shaped [PhCB₁₀H₁₀]^– residue capped by a pentuply-bridging carbonyl group whose C–O distance of 1.245(3)Å and position over the open carborane face, 2.001(3)Å from the cage carbon atom, are readily rationalized by frontier orbital considerations.