Synthesis and FET characteristics of phenylene-vinylene and anthracene-vinylene compounds containing cyano groups

Abstract

A series of oligo-p-phenylene-vinylenes (OPVs) 1–3 and anthracene-vinylenes (AVs) 4–6 containing cyano groups have been synthesized and their photophysical, electrochemical and carrier transporting properties have been systematically examined. OPVs 2a and b, having cyano groups at the α-vinyl position, exhibited higher electron-accepting properties. Reduction peaks of OPV 2a in the cyclic voltammograms were observed as two-step reversible waves. OPVs 2a and b showed high electron mobilities in FET devices with bottom contact configuration. On the contrary, OPV 3a, which has cyano groups at the β-vinyl position, exhibited a high electron mobility of 0.3 cm² V⁻¹ s⁻¹ with a top contact configuration. Introduction of biphenyl units enhanced the fluorescence efficiency in the solid state. In the case of AVs 5 and 6, cyano groups introduced at the 9 and 10-positions play an important role in injecting and transporting electrons. FET devices based on AVs 5 and 6 showed ambipolar behavior in the same device conditions.