Syntheses, characterisation, infrared and Mo-95 NMR spectroscopy of some coordinated oxo-molybdenum(VI) complexes

Adducts with MoO42-tetrahedra coordinated to Cr(III) or Co(III) complexes have been synthesised and studied by IR and high resolution Mo-95 NMR spectroscopy. The Mo-95 chemical shifts of the adducts with cobalt(III) lie in the range -33.2 to +49.4 ppm. This may be compared with an overall known chemical shift range in excess of 7000 ppm and implies a similarity in the molybdenum environment in all cases. For adducts with chelated cobalt(III) complexes several rather broad Mo-95 signals are obtained with linewidths up to 260 Hz.