Complete Series of Chiral Paramagnetic Molecular Conductors Based on Tetramethyl-bis(ethylenedithio)-tetrathiafulvalene (TM-BEDT-TTF) and Chloranilate-Bridged Heterobimetallic Honeycomb Layers
Résumé
Electrocrystallization of enantiopure (S,S,S,S)- and (R,R,R,R)-tetramethyl-bis(ethylenedithio)-tetrathiafulvalene
(TM-BEDT-TTF) donors, as well as the racemic mixture, in the presence of potassium cations and the tris(chloranilato)-
ferrate(III) [Fe(Cl2An)3]3− paramagnetic anion afforded a complete series of chiral magnetic molecular conductors
f o r m u l a t e d a s β - [ ( S , S , S , S ) - T M - B E D T - TTF]3PPh4[KIFeIII(Cl2An)3]·3H2O (1), β-[(R,R,R,R)-TMBEDT- TTF]3PPh4[KIFeIII(Cl2An)3]·3H2O (2), and β-[(rac)- TM-BEDT-TTF]3PPh4[KIFeIII(Cl2An)3]·3H2O (3). 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 Λ and Δ enantiomers of the paramagnetic complex with potassium cations alternate with organic layers where the chiral donors are arranged in the β 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 × 10−4 S cm−1.....