Syntheses, Characterization, and Properties of Functionalized 9,10-Bis(1,3-dithiol-2-ylidene)-9,10-dihydroanthracene Derivatives and Tricarbonylrhenium(I) Complexes

New p-extended tetrathiafulvalenes (exTTF) 4a, 4b, 5a, and 5b have been synthesized by direct phosphite-mediated cross-couplings of anthraquinone with 1,3-dithiole-2-thione derivatives. Further coordination reactions of the exTTF ligands including the phenanthroline unit (5a and 5b) with [Re(CO)5Cl] afford interesting tricarbonylrhenium(I) complexes 6a and 6b, respectively. The X-ray crystal structures of compounds 4a and 4b show a saddlelike conformation of the exTTF framework. The electrochemical and spectroscopic properties of compounds 4a6a and 4b6b have been studied. The results suggest that the oxidation of the exTTF derivatives shows the typical quasi-reversible two-electron oxidation wave of the exTTF core at potentials that vary depending on the substituents.