A molybdenum tris-(di-thiol-ene) complex coordinates to three bound cobalt centers in three different ways.

The synthesis and structural characterization of the mol-ecular compound (μ-benzene-1,2-di-thiol-ato)hexa-carbonyl-bis-(μ-1,1,1,4,4,4-hexafluorobut-2-ene-2,3-dithiolato)tricobaltmolybdenum, [CoMo(CFS)(CHS)(CO)] or Mo(tfd)(bdt)(Co(CO)) (tfd is 1,1,1,4,4,4-hexafluorobut-2-ene-2,3-dithiolate and bdt is benzene-1,2-di-thiol-ate), are reported. The structure of the mol-ecule contains the molybdenum tris-(di-thiol-ene) complex Mo(tfd)(bdt) coordinated as a multidentate ligand to three cobalt dicarbonyl units. Each of the three cobalt centers is relatively close to molybdenum, with Co⋯Mo distances of 2.

Rapid, covalent addition of phosphine to dithiolene in a molybdenum tris(dithiolene). A new structural model for dimethyl sulfoxide reductase.

Triphenylphosphine (PPh(3)) rapidly and reversibly adds to the bdt ligand in the molybdenum tris(dithiolene) complex Mo(tfd)(2)(bdt) [tfd = S(2)C(2)(CF(3))(2); bdt = S(2)C(6)H(4)], turning chelating bdt into the monodentate zwitterionic ligand SC(6)H(4)SPPh(3). A second PPh(3) molecule fills the newly created open site in the crystallographically characterized product Mo(tfd)(2)(SC(6)H(4)SPPh(3))(PPh(3)), which is a structural model for dimethyl sulfoxide (DMSO) reductase. While the complex is only a precatalyst for reduction of DMSO by PPh(3) (the initially low catalytic rate increases with time), Mo(tfd)(2)(SMe(2))(2) was found to be catalytically active without an induction period.

Tuning of the spin distribution between ligand- and metal-based spin: electron paramagnetic resonance of mixed-ligand molybdenum tris(dithiolene) complex anions.

Electron paramagnetic resonance spectra of homoleptic and mixed-ligand molybdenum tris(dithiolene) complex anions [Mo(tfd)(m)(bdt)(n)](-) (n + m = 3; bdt = S(2)C(6)H(4); tfd = S(2)C(2)(CF(3))(2)) reveal that the spin density has mixed metal-ligand character with more ligand-based spin for [Mo(tfd)(3)](-) and a higher degree of metal-based spin for [Mo(bdt)(3)](-): the magnitude of the isotropic (95,97)Mo hyperfine interaction increases continuously, by a factor of 2.5, on going from the former to the latter. The mixed complexes fall in between, and the metal character of the spin increases with the bdt content.

New insight into reactions of Ni(S2C2(CF3)2)2 with simple alkenes: alkene adduct versus dihydrodithiin product selectivity is controlled by [Ni(S2C2(CF3)2)2]- anion.

The nickel bis(dithiolene) complex Ni(S2C2(CF3)2)2 employs its sulfur centers in reactions with alkenes, and stable interligand S-bonded alkene adducts can be formed. The present study shows that the selectivity of alkene binding to charge-neutral Ni(S2C2(CF3)2)2 is influenced by the anion [Ni(S2C2(CF3)2)2]-. In the absence of anion, formation of substituted dihydrodithiins (intraligand addition) dominates, whereas the presence of anion allows for the formation of stable interligand adducts.