Charge transfer complexes and radical cation salts of chiral methylated organosulfur donors

S. Yang , F. Pop , C. Melan , A. C. Brooks , Lilian Martin (1) , P. Horton (2) , P. Auban-Senzier (3) , Rikken G.L.J.A. (4, 5) , N. Avarvari (6) , J. D. Wallis

1 SUBATECH - Laboratoire SUBATECH Nantes
2 Institute of Geomatics and Analysis of Risk (IGAR)
3 LPS - Laboratoire de Physique des Solides
4 LNCMI-T - Laboratoire national des champs magnétiques intenses - Toulouse
5 LNCMP - Laboratoire National des Champs Magnétiques Pulsés
6 CIMMA - Chimie, Ingénierie Moléculaire et Matériaux d'Angers

The single crystal X-ray structure of the all-axial conformer of the (R, R, R, R) enantiomer of the chiral donor tetramethyl-BEDT-TTF (TM-BEDT-TTF) was described and compared to the all-equatorial conformer. (S, S, S, S)-Tetramethyl-BEDT-TTF formed crystalline 1 : 1 complexes with TCNQ and TCNQ-F-4, as well as a THF solvate of the TCNQ complex. Donors bis((2S, 4S)-pentane-2,4-dithio) tetrathiafulvalene and (ethylenedithio)((2S, 4S)-pentane-2,4-dithio) tetrathiafulvalene, which contain seven-membered rings bearing chirally oriented methyl groups, only formed complexes with TCNQ-F4. The TCNQ-F4 complexes contain planar organosulfur systems, in contrast to the TCNQ complexes in which there is minimal charge transfer. A variety of crystal packing modes were observed. Electrocrystallization experiments with both enantiomers and the racemic form of tetramethyl-BEDT-TTF afforded mixed valence radical cation salts with the AsF6 and SbF6 anions formulated as (TM-BEDT-TTF)(2)XF6 (X = As, Sb). Electrical conductivity was only found in one charge transfer complex, while the radical cation salts are all semiconducting.

Domaines: Supraconductivité [cond-mat.supr-con]

S. Yang, F. Pop, C. Melan, A. C. Brooks, Lilian Martin, et al.. Charge transfer complexes and radical cation salts of chiral methylated organosulfur donors. CrystEngComm, 2014, 16 (19), pp.3906-3916. ⟨10.1039/c3ce42539h⟩. ⟨hal-01048740⟩