A new crystal structure for (BEDT-TTF)_2SbF_6 and some of its physical properties

摘要

A new crystal structure for bis(ethylenedithio)tetrathiafulvalene [(BEDT-TTF)_2 SbF_6] was determined by single crystal X-ray diffraction. The crystal structure was refined in the P 1 space group at room temperature. Crystal data for new structure are as follows: triclinic, a = 8.670 (2) A,b = 8-664 (2) A, c = 16.842 (5) A, alpha = 89 deg center dot 29 (2), beta= 90deg center dot 71 (3), gamma = 92 deg center dot 67 (1), V = 1263.64 A~3, Z = 2, D_x = 2.136 g cm~(-3), (Mo-K alpha), gamma = 0-7107 A, R = 0057 for a total of 5517 independent reflections. The donors form a trimerized column, and the band structure calculated by the tight-binding approximation shows band insulator properties. The temperature dependent of the d.c. resistivity shows a semiconducting behaviour with room temperature resistivity along the c-axis; rho_(290 K) = 5.6 ohm cm.