Syntheses, reactivity, and crystal structures of molybdenum complexes with pyridine-2-thionate (pyS)-containing ligands:: Crystal structures of [Mo(η3-C3H5)(CO)2]2(μ-η1,η2-pyS)2, exo-[Mo(η3-C3H5)(CO)(η2-pyS)(η2-dppe)], [Mo(CO)3(η1-SC5H4NH)(η2-dppm)], and [Mo(CO)(η2-pyS)2(η2-dppm)]

The doubly bridged pyridine-2-thionate (pyS) dimolybdenum complex [Mo(eta(3)-C3H5)(CO)(2)](2)(mu-eta(1),eta(2)-pyS)(2) (1) is accessible by the reaction of [Mo(eta(3)-C3H5)(CO)(2)(CH3CN)(2)Br] with pySK in methanol at room temperature. Complex I reacts with piperidine in acetonitrile to give the complex [Mo(eta(3)-C3H5)(CO)(2)(eta(2)-pyS) (C5H10NH)] (2). Treatment of I with 1,10-phenanthroline (phen) results in the formation of complex [Mo(eta(3)-C3H5)(CO)2(eta(1)-pyS)(phen)] (3), in which the pyS ligand is coordinated to Mo through the sulfur atom. Four conformational isomers, endo,exo-complexes [Mo(eta(3)-C3H5)(CO)(eta(2)-pyS)(eta(2)-diphos)] (diphos = dppm, 4a-4d; dppe, 5a-5d), are accessible by the reactions of 1 with dppm and dppe in refluxing acetonitrile. Homonuclear shift-correlated 2-D P-31{H-1}-P-31{H-1} NMR experiments of the mixtures 4a-4d have been employed to elucidate the four stereoisomers. The reaction of 4 and pySK or [MO(CO)(3)(eta(1)-SC5H4NH)(eta(2)-dppm)] (6) and O-2 affords allyl-displaced seven-coordinate bis(pyridine-2-thionate) complex [MO(CO)(eta(2)-PYS)(2)(eta(2)-dppm)] (7). All of the complexes are identified by spectroscopic methods, and complexes 1, 5d, 6, and 7 are determined by single-crystal X-ray diffraction. Complexes 1 and 5d crystallize in the orthorhombic space groups Pbcn and Pbca with Z = 4 and 8, respectively, whereas 6 belongs to the monoclinic space group C2/c with Z = 8 and 7 belongs to the triclinic space group P (1) over bar with Z = 2. The cell dimensions are as follows: for 1, a = 8.3128(1) Angstrom, b = 16.1704(2) Angstrom, c = 16.6140(2) Angstrom; for 5d, a = 17.8309(10) Angstrom, b = 17.3324(10) Angstrom, c = 20.3716(11) Angstrom; for 6, a = 18.618(4) Angstrom, b 16.062(2) Angstrom, c 27.456(6) Angstrom, p = 96.31(3)degrees; for 7, a = 9.1660(2) Angstrom, b = 12.0854(3) Angstrom, c = 15,9478(4) Angstrom, alpha = 78.4811(10)degrees, beta = 80.3894(10)degrees, gamma = 68.7089(11)degrees.