Experimental and theoretical evidence of -d interactions in supramolecular assemblies based on TTF-CH-Py ligands tethered to Mo6Xi8 octahedral molybdenum halide cluster cores

Eur. J. Inorg. Chem., 2009, 2153-2161Synthesis, characterization, and physical properties of [Mo6Xi8(TTF-CH=CH-Py)a6]4+ supramolecular assemblies [TTF = tetrathiafulvalene; Py = pyridine; X = Cl (1), Br (2),I (3)] resulting from the reaction between [Mo6Xi8(OSO2CF3)6]2- cluster precursor and TTF-CH=CH-Py ligands were investigated. They are based on the association of the strongly delocalized metallic electron [Mo6Xi8]4+ cluster cores with six redox-active π-conjugated TTF-CH=CH-Py terminal ligands attached to the Mo clusters through the pyridinyl group. Synergetic π-d interactions between the organic ligands and the cluster core were experimentally evidenced by electrochemistry and absorption measurements, and corroborated by DFT calculations