Redox- And Solvato-Magnetic Switching In A Tetrathiafulvalene-Based Triad Single-Molecule Magnet

The first simultaneous redox and solvato-magnetic switching was achieved. The dinuclear complex [Dy-2(hfac)(6)(H(2)SQ)]center dot CH2Cl2(Dy(2)H(2)SQ) (where hfac = 1,1,1,5,5,5-hexafluoroacetylacetonate andH(2)SQ= 2,2 '-benzene-1,4-diylbis(6-hydroxy-4,7-di-tert-butyl-1,3-benzodithiol-2-ylium-5-olate) was reversibly oxidized into the dinuclear complex [Dy-2(hfac)(6)(H2O)(2)(Q)] (Dy(2)Q) (whereQ= 2,2 '-cyclohexa-2,5-diene-1,4-diylidenebis(4,7-di-tert-butyl-1,3-benzodithiole-5,6-dione)) inducing the reversible coordination of water molecules to the Dy(III)ion. Magnetic susceptibility measurements andab initioCASSCF/SI-SO calculations, confirmed by Cantilever Torque Magnetometry measurements, demonstrated thatDy(2)H(2)SQis a Single-Molecule Magnet with a magnetic relaxation 7000 times slower thanDy(2)Q(at 3 K) allowing a "ON-OFF" switching of the magnetic bistability.