The tmbp Dianion in the Contact Ion Pair [(tmbp)Na2(dme)1.5]n and in the Solvent-Separated Ion Pair [tmbp][(2.2.1)Li]2 This work was supported by the CNRS and the Ecole Polytechnique; tmbp=4,4′,5,5′-tetramethyl-2,2′-biphosphinine, DME=1,2-dimethoxyethane.

Abstract

A surprising polymeric structure (see picture) results from the two‐electron reduction of a 2,2′‐biphosphinine with sodium/naphthalene in dimethoxyethane. When reduction is carried out with lithium in the presence of (2.2.1) cryptand, the reduced ligand adopts a trans configuration in the solid state. DFT calculations clearly indicate a phosphaallylic‐type structure.