Electron acceptor molecules: new, expedient synthesis of substituted 7,7,8,8-tetracyano-p-quinodimethane (TCNQ) derivatives and the X-ray crystal structure of 2,5-dibromo-TCNQ

Abstract

A range of TCNQ derivatives,viz. 2,5-dichloro-, 2,5-dibromo-, 2,5-dimethoxy-, 2-methoxycarbonyl- and benzo-TCNQ, and 11,11,12,12-tetracyanonaphtho-2,6-quinodimethane (TNAP), have been efficiently synthesised using 2-chlorcbenzyl thiocyanate as the source of electrophilic cyanide in reactions with the corresponding di(cyanomethyl)benzene or di(cyanomethyl)naphthalcne derivatives. The X-ray crystal structure of 2,5-dibrorno-TCNQ has been determined: the molecule is essentially planar with the dicyanomethylene groups bent away from the adjacent bromine atoms. There are close intermolecular Br ⋯ N contacts in the structure.