MOLECULAR DESIGN AND SYNTHESIS OF FERROMAGNETIC AND FERRIMAGNETIC INORGANIC POLYMERS AND COMPLEXES WITH TETRATHIOLATE LIGANDS

The orbital-symmetry rules for superexchange couplings of unpaired ele ctrons via ligands were applied to one-dimensional (1D) polymers compo sed of heteropoly transition-metal tetrathiolates (poly(M1TM2), T: tet rathiolate). The polymers composed of the Cu(II)-Fe(III)(LS) and Ni(II )(HS)-Fe(III)(LS) units are predicted to be ferromagnetic within 1D ch ains, whereas several polymers such as the Co(II)(HS)-Cu(II) alternati ng one are considered to be ferrimagnetic. Ferromagnetic metals, dense Kondo and spin-mediated superconductors composed of trinuclear M2TM1T M2 complexes (M1=Ni) are also designed on the basis of the theoretical results. According to these guiding principles, we have performed the synthesis of ferro- and ferrimagnetic polymers composed of heteropoly transition-metal tetrathiolates (poly(M1TM2), T: tetrathiolate). The magnetic measurements of the solids were also carried out and the obse rved intrachain effective exchange integrals are summarized.