Journal of the American Chemical Society, Vol.134, No.24, 9886-9889, 2012
Crossing the Insulator-to-Metal Barrier with a Thiazyl Radical Conductor
The layered-sheet architecture of the crystal structure of the fluoro-substituted oxobenzene-bridged bisdithiazolyl radical FBBO affords a 2D pi-electronic structure with a large calculated bandwidth. The material displays high electrical conductivity for a f = 1/2 system, with sigma(300 K) = 2 x 10(-2) S cm(-1). While the conductivity is thermally activated at ambient pressure, with E-act, = 0.10 eV at 300 K, indicative of a Mott insulating state, E-act is eliminated at 3 GPa, suggesting the formation of a metallic state. The onset of metallization is supported by infrared measurements, which show closure of the Mott-Hubbard gap above 3 GPa.