Synthesis and properties of T-shaped organic conjugates based on 3,6-diarylpyridazine-fused tetrathiafulvalene.

A facile synthetic approach to the π-expanded tetrathiafulvalene derivatives is described. The Suzuki reaction of 3,6-dichloropyridazine-fused tetrathiafulvalenes with phenyl boronic acid or biphenyl boronic acid gave a series of novel T-shaped organic π-conjugates. The electronic properties of the conjugates were studied experimentally by the combination of cyclic voltammetry and UV-vis spectroscopy. Their HOMO and LUMO energy levels are estimated to be about -5 eV and -3.2 eV, which are the air operating stability ranges in the p-channel and n-channel field effect transistors, respectively. Only one conjugate bearing the longer alkyl chain (n = 1, R = n-C18H37) was verified to self-assemble into lamellar structures in the mesogenic phase and the best measured charge carrier mobility of its thin-film devices was 4.5 × 10(-5) cm(2) V(-1) s(-1).