Novel molecules for the design of organic conductors. Synthesis of 7,7,8,8-tetracyano-2,5-bis(3-phenylpropyl)-p-quinodimethane and N,N′-dicyano-2,5-bis(3-phenylpropyl)-p-quinodiimine and X-ray structure of the TCNQ derivative

Abstract

The novel 7,7,8,8-tetracyano-2,5-bis(3-phenylpropyl)-p-quinodimethane 2 and N,N′-dicyano-2,5-bis(3-phenylpropyl)-p-quinodiimine 3 in which the acceptor TCNQ and DCNQI moieties are covalently linked to weak donors, phenyl rings, by three methylene units have been synthesized and studied as intended donor–acceptor–donor (D–A–D) systems. The cyclic voltammetry data reveal two one-electron reversible reduction waves to the corresponding anion-radical and dianion. The novel molecules 2 and 3 behave, in solution, as simple TCNQ and DCNQI derivatives, respectively. A structural study by X-ray diffraction on the TCNQ-type molecule 2 shows a very planar, nondistorted TCNQ ring with isolated D ⋯ A ⋯ D triplets between the central TCNQ moiety of a molecule and two phenyl rings of two other different molecules.