VIBRATIONAL AND ELECTRONIC SPECTROSCOPY OF THE OCTACYANODIMOLYBDATE ION, [MO-2(CN)(8)](4-)

The infrared, Raman and resonance-Raman spectra of [NEt4](4)[Mo-2(CN)( 8)] have been recorded in solution and the solid state, and the import ant features of each assigned. The strong, polarised Raman band at 411 cm(-1) is assigned to v(MoMo), the highest reported v(MoMo) value for a quadruply bonded, unbridged dimolybdenum complex. Resonance-Raman s tudies have shown that v(MoMo) is coupled to a strong electronic band at 16 580 transition is axially polarised, consistent with its assignm ent to the (delta)(delta) <-- (delta)(2) transition.