Synthesis And Characterization of Mo(V)-oxido Complexes Containing the Thiocyanato-N Ligand

(P(C6H5)4)2{MoO(NCS)5}(1) crystallized after addition of (P(C6H5)4)Br to the mixture obtained by refluxing (pyH)5{MoOCl4(H2O)}3Cl2 (py = pyridine) and KSCN in acetonitrile, and also by oxidation of ((y-pic)2H){Mo(NCS)4 (y-pic)2}(pic = picoline) with Br2 in air. The oxidation of ((y-pic)2H){Mo(NCS)4(y-pic)2}with a considerably lower concentration of Br2 in air gave (y-picH)6{Mo2O3(SO4)(NCS)6}(SO4) (2). (pyH)8{Mo2O3(NCS)8}X4 (X = Br, 3; X = Cl, 4) were isolated after addition of pyHX to the hydrolysis product of {MoO(NCS)5}2–. The compounds were characterized by IR spectroscopy and single crystal X-ray diffraction analysis. The positions of the v(CN) and s(NCS) bands indicate N-bonding of the NCS groups and are in agreement with the crystal-structure results.