Acta Crystallographica Section B

Structural Science

Volume 55, Part 4 (August 1999)

research papers

Acta Cryst. (1999). B55, 601-606 [ doi:10.1107/S0108768199003468 ]

The single-crystal structure of the organic superconductor _CO-(BEDT-TTF)₂I₃ from a powder grain

D. Madsen, M. Burghammer, S. Fiedler and H. Müller

Abstract: Synchrotron radiation diffraction data have been collected at 200 K on a microscopic single crystal (dimensions 12 × 10 × 2 µm) of the title compound, where BEDT-TTF is bis(ethylenedithio)tetrathiafulvalene, C₁₀H₈S₈. The quality of the diffraction data allowed a full structure refinement and enabled the determination of structural details such as the conformations of the ethylene groups as well as the occupancy of the triiodide sites. The compound was found to be slightly iodine-deficient and better described as [beta] _CO-(BEDT-TTF)₂I_3-x [x = 0.014 (3)]. One of the ethylene groups of the BEDT-TTF cation is disordered at this temperature and exists in two distinct conformations with occupancies which are identical within the standard uncertainty.