Assembly of partially oxidized tetrathiafulvalene in layered phosphates. Formation of conducting organic-inorganic hybrids by intercalation

Intercalation and ion-exchange reactions have been used for the synthesis of novel inorganic-organic hybrid materials comprised of tetrathiafulvalene (TTF) conducting chains interleaved with insulating zirconium phosphate layers. Two different synthetic strategies are described. in the first approach, we have attempted the oxidative insertion of neutral TTF into a Zr(PO4)(HPO4)(2) . 2H(2)O host preexchanged with CU2+. In the second method, surfactant or long-chain alcohols have been used to expand the layers of the host structure, allowing the intercalation of partially charged TTF molecules. This latter approach produced materials with metal-like conductivity that exceeds by a factor of 10(7) that of the precursors. These compounds have been characterized by vibrational, UV-vis, acid EPR spectroscopies, and transport properties (conductivity and thermoelectrical power) have been measured as a function of the temperature from -150 to 50 degrees C. The properties observed show marked similarity with those displayed by mixed valence TTF halides and pseudohalides, The reactions occur topotactically, and the increase in interlayer distance is compatible with an orientation of TTF perpendicular, or nearly, to the host layers.