Syntheses, crystal structures, and catalysis by polymeric dioxomolybdenum(VI) complexes with similar (iso)nicotinohydrazones

Polymeric dioxomolybdenum(VI) complexes, [MoO2L](n) (L=L-1=N-(2-hydroxybenzylidene)nicotinohydrazide for 1, L=L-2=N-(2-hydroxy-5-methoxybenzylidene)isonicotinohydrazide for 2), were prepared and characterized by physico-chemical, spectroscopic methods, and single-crystal X-ray determination. Complex 1 crystallizes in the orthorhombic space group P2(1)2(1)2(1) with a=7.6568(4), b=11.6315(7), c=15.2211(9)angstrom, V=1355.59(13)angstrom(3), Z=4, R-1=0.0181, wR(2)=0.0464, and S=1.097. Complex 2 crystallizes in the monoclinic space group P2(1)/n with a=11.2516(6), b=11.8134(7), c=12.4371(6)angstrom, =116.2210(10)degrees, V=1483.02(14)angstrom(3), Z=4, R-1=0.0399, wR(2)=0.0874, and S=1.096. X-ray analysis indicates that Mo in each complex is octahedral with two oxo groups and N2O2 donor set of the nicotinohydrazone or isonicotinohydrazone. The complexes are efficient catalysts for oxidation of olefins.