Chemical and structural studies on the 2,4- and 2,3-isomers of the dicarba-nido-hexaborate(1–) ion, C2B4H7–, and some dipolar derivatives

Abstract

The closo-carborane 1,6-C₂B₄H₆ reacts with trimethylamine to form 5-Me₃N⁺-nido-2,4-C₂B₄H₆^–. The latter compound rearranges in chloroform, or thermally, to the 3-Me₃N⁺ isomer. The parent 2,4-C₂B₄H₇^– ion is obtained both from the action of NaH on either 3- or 5-Me₃N⁺-2,4-C₂B₄H₆^– and from the slow reaction of closo-1,6-C₂B₄H₆ with either NaH or LiH. The structures of 2,4-C₂B₄H₇^– and 2·3-C₂B₄H₇^– and the Me₃N⁺-2,4-C₂B₄H₆^– isomers are correlated with ¹¹B and ¹H n.m.r. data.