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We report the first examples of radical-cation salts of BEDT-TTF with spiroborate anions [B(mandelate)2]− and [B(2-chloromandelate)2]−, synthesized from either enantiopure or racemic bidentate mandelate or chloromandelate ligands. In the salts prepared using enantiopure ligands only one of two diastereoisomers of the spiroborate anion is incorporated, with the boron centre having the same stereochemistry as the enantiopure ligand. For the racemic salts one racemic pair of spiroborate anions containing an R and an S mandelate ligand is incorporated. In certain solvents helical crystals were obtained when using spiroborate anions with enantiopure ligands. Electrical and magnetic properties, and band structure calculations are reported.

Electrocrystallisations of the chiral donor molecule S,S-bis(2-hydroxylpropylthio)ethylenedithiotetrathiafulvalene have produced a series of 1 : 1 semiconducting radical-cation salts with anions bromide, chloride, perchlorate and hexafluorophosphate. The flexibility and hydrogen bonding ability of the donor's chiral side chains lead to three quite different packing arrangements of donor cation pairs. Conductivity is maintained despite significant separations of donor cation pairs in some cases.

This article reports a family of new radical-cation salts of bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) with tris(oxalato)rhodate: three salts with the formula β′′-(BEDT-TTF)4[(cation)Rh(C2O4)3]·solvent (solvent = fluorobenzene, chlorobenzene, or bromobenzene) and one with the formula pseudo-κ-(BEDT-TTF)4[(NH4)Rh(C2O4)3]·benzonitrile. We report here the syntheses, crystal structures, electrical properties and Raman spectroscopy of these new molecular conductors. The bromobenzene salt shows a decrease in resistivity below 2.5 K indicative of a superconducting transition and a Shubnikov–de Haas oscillation with a frequency of 232 T and effective mass m* of 1.27me.

Hydroxymethyl-BEDT-TTF is converted by tosylation and elimination into exo-methylene-BEDT-TTF whose exocyclic double bond leads to a small increase in the oxidation potential, and from which radical cation salts with perchlorate and triiodide have been prepared, the latter showing semiconductor properties. Allyloxymethyl- and allylthiomethyl-BEDT-TTF, the first BEDT-TTF derivatives with an alkene in the side chain, have been prepared, along with a 1 : 2 radical cation perchlorate salt of the former, an insulator which contains a donor dication.