BEDT-TTF-based organic conductors with [MBr4]2− anions, M = Cd, Co, Zn, Mn, Hg. Effect of solvent

• [MBr4]2− anions and PhF, 2-XC6H4CH3, ClCnH2n−1 solvents were combined with BEDT-TTF.
• (BEDT-TTF)4MBr4(solvent) and (BEDT-TTF)3MBr4 organic conductors were isolated.
• In (BEDT-TTF)3CoBr4, alternation of BEDT-TTF layers of different structure was found.
• In (BEDT-TTF)4CdBr4(C7H7Br), layers composed of differently directed stacks alternate.
• Modification of conducting and anion layers changes its phase transition temperature.

New layered conductors of (BEDT-TTF)4(Anion)(solvent) and (BEDT-TTF)3(Anion) stoichiometery (BEDT-TTF = bis(ethylenedithio) tetrathiafulvalene) with double-charged anions of tetrahedral geometry, [MBr4]2−, M = Cd, Co, Zn, Mn, Hg, have been synthesized using 2-halogenotoluenes, fluorobenzene and chlorocycloalkanes as solvents. The effect of solvent on composition and electroconducting properties of the compounds has been traced. Crystal structure of θ-(BEDT-TTF)4CdBr4(C7H7Br) and (BEDT-TTF)3CoBr4 has been determined. In the first compound, conducting layers show similar structure but differ in the direction of the BEDT-TTF stacks. In the second one, two crystallographically independent BEDT-TTF layers are considerably different from each other. In layer I, radical cations are linked in ribbons by side-to-side type. In layer II, BEDT-TTF forms dimers stacked with a fan-shaped offset. The ESR linewidths for (BEDT-TTF)4(MBr4)(solvent), solvent = C7H7Cl, C6H5F are close to the linewidth for θ-(BEDT-TTF)4CdBr4(C7H7Br) that allows one to assume similar structural packing motifs.

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