A Bimetallic Benzene-1,2,4,5-Tetrathiolate (btt) Molybdenocene Complex Cp2 Mo(btt)MoCp2 : Radical and Diradical States.

Benzene-1,2,4,5-tetrathiolate (btt) has been used as a bridging ligand to prepare a redox active (molybdenocene dithiolene)-based bimetallic complex Cp2 Mo(btt)MoCp2 , which exhibits four successive electron transfers up to the tetracation. Spectro-electrochemical investigations together with DFT and TD-DFT calculations evidence that the two electroactive MoS2 C2 metallacycles are electronically coupled in the monocationic as in the dicationic state. Two salts of the dication [Cp2 Mo(btt)MoCp2 ]2+ have been structurally characterized with PF6 - and HSO4 - counterions, showing different chair or boat conformations associated with variable folding angles of the two MoS2 C2 metallacycles along the S-S hinge. The bis-oxidized dicationic complex exhibits a diradical character, with both radicals essentially localized on the metallacycles and with antiferromagnetic coupling evidenced from magnetic susceptibility measurements.

4f Gadolinium(III) complex involving tetrathiafulvalene-amido-2-pyrimidine-1-oxide as a ligand.

A coordination gadolinium(III) mononuclear complex involving the new redox-active tetrathiafulvaleneamido-2-pyrimidine-1-oxide is synthesized. The X-ray structure of the 1:3 gadolinium complex [Gd(hfac)(3)(TTF-CONH-2-Pym-1-oxide)(3)](CH(2)Cl(2)).0.5C(6)H(14) reveals that the coordination polyhedron of the paramagnetic 4f (S = (7)/(2)) Gd(III) ion can be described as a 4,4,4-tricapped trigonal prism. The three-coordinated TTF derivatives adopt a fac conformation with a pseudohelicoidal arrangement. A radical-cation salt of this new ligand is reported. Such a coordination complex is an innovative building block for the pi-f system and the introduction of new physical properties.

First trinuclear paramagnetic transition metal complexes with redox active ligands derived from TTF: Co2M(PhCOO)6(TTF-CH=CH-py)2.2CH3CN, M = CoII, MnII.

The first paramagnetic homo- and hetero-metallic trinuclear complexes with redox active ligands derived from TTF are synthesized, the central metal ion has an octahedral coordination sphere while the outer Co(II) ions are in a distorted bipyramidal surrounding, bearing TTF-ligands, the magnetic properties show antiferromagnetic coupling leading to a magnetic ground state.