Crystal Structures and Electrical Properties of BEDT-TTF Coeipounds

Abstract
The crystal structure and the electrical resistivities of BEDT-TTF compounds are reported. The most prominent feature of the crystal structure is the side-by-side array of BEDT-TTF molecules. The steric effects of the ethylene groups prevent the infinite stacking of the molecules. The electrical properties and the change in the X-ray diffraction patterns of β-(BEDT-TTF)2PF6 suggest that β-(BEDT-TTF)2PF6 is a one-dimensional conductor along the transverse direction. A simple band calculation indicates that (BEDT-TTF)2Cl04(C2H3C13) 0.5 is a two-dimensional semimetal. (BEDT-TTF)3(C104)2 shows a metal-insulator transition at 170 K, which is consistent with the one-dimensional band structure of this compound.