Molecular materials based upon organic π-donors and magnetic anions
Résumé
Electrochemical combination of the magnetic dinuclear anion [MM′(C2O4)(NCS)8]4- (MM′ = CrCr, CrFe) or paramagnetic mononuclear anion [Cr(NCS)6]3- with the ET organic π-donor (ET = BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene) gives rise to two new series of molecular hybrid salts formulated (ET)5[MM′(C2O4)(NCS)8] (MM′ = CrCr (1), CrFe (2)), (ET)8[MM′(C2O4)(NCS)8] (3), (ET)5.5[Cr(NCS)6] (4) and (ET)5[(C2H5)4N] [Cr(NCS)6](THF) (5) (THF = tetrahydrofuran). The crystal structures consist of alternating organic and inorganic layers. The organic part does not produce any detectable effect on the magnetic properties coming from the inorganic sublattice. They indicate the presence of antiferromagnetic coupling in the homometallic dimers (1 and 3), while the coupling is ferromagnetic in the heterometallic one (2). Conductivity measurements reveal a metallic state for compounds 3 and 5.