Complete Series of Chiral Paramagnetic Molecular Conductors Based on Tetramethyl-bis(ethylenedithio)-tetrathiafulvalene (TM-BEDT-TTF) and Chloranilate-Bridged Heterobimetallic Honeycomb Layers

Electrocrystallization of enantiopure (S,S,S,S)and (R,R,R,12)-tetramethyl-bis(ethy1enedithio)-tetrathiafulvalene (TM-BEDT-TTF) donors, as well as the racemic mixture, in the presence of potassium cations and the tris(chloranilato)ferrate(111) [Fe(Cl(2)An)(3)](3) paramagnetic anion afforded a complete series of chiral magnetic molecular conductors formulated as beta-[(S,S,S,S)-TM-BEDT-TTF](3)PPh4[(KFeIII)-Fe-I(Cl(2)An)(3)]center dot 3H(2)O (1), beta-[(R,R,R,R)-TM-BEDT-TTF](3)PPh4[(KFeIII)-Fe-I(Cl(2)An)(3)]center dot 3H(2)O (2), and beta-[(rac)TM-BEDT-TTF](3)PPh4[K(I)Fe(III)Cl(2)An)(3)]center dot 3H(2)O) . Compounds 1-3 are isostructural and crystallize in triclinic space groups (P1 for 1 and 2, P-1 for 3) showing a segregated organic inorganic crystal structure, where anionic honeycomb layers obtained by self-assembling of the A and Delta enantiomers of the paramagnetic complex with potassium cations alternate with organic layers where the chiral donors are arranged in the 13 packing motif Compounds 1-3 show a molecular packing strongly influenced by the topology of the inorganic layers and behave as molecular semiconductors with room-temperature conductivity values of ca. 3 X 10(-4) S cm(-1). The magnetic properties are dominated by the paramagnetic S = 5/2 [Fe(Cl(2)An)(3)](3) anions whose high-spin character is confirmed by magnetic susceptibility measurements. The correlation between crystal structure and conducting behavior has been studied-by means of tight-binding band structure calculations which support the observed conducting properties.