Applications of molybdenum-95 NMR spectroscopy. 14. Construction of a transverse probe for the detection of broad 95Mo resonances in solution. Studies on Binuclear Mo(II) compounds

Abstract

The use of a specifically constructed probe having a transverse solenoid coil operating at 13 MHz has permitted convenient detection of 95Mo resonances in solutions of [Mo] = 5 × 103̄ M for compounds whose linewidths, W 1 2, are in excess of 1000 Hz. Application of a three-pulse sequence, 90°+x (acq)+-180°x-τ-90°-x (acq)+ and shielding of the coil with lead substantially reduces ring-down times. A series of binuclear molybdenum(II) species which feature formal Mo-Mo quadruple bonds were examined. 95Mo resonances were detected in the range 3227-4148 ppm and this is the most deshielded class of molybdenum compounds so far discovered. Observed linewidths covered the range 200-1500 Hz. Those for..