Raman spectra of a number of triply bonded M2X6 (M = Mo, W; X = alkoxide, alkyl) compounds have been obtained. Several exhibit a band assignable to the metal-metal stretching vibration nu(Mequivalent toM). This band was not identified in earlier studies of the M-2(NMe2)(6) compounds. We have attempted to correlate the Raman vibrational data with structural data from single-crystal X-ray diffraction studies. Diffraction studies of the M-2(O-1-4-pentyl[2.2.2]bicyclooctyl)(6) species show a crowded environment around the dimetal core, but the M-M-O angles differ substantially from 900. Thus, this angle does not solely determine the extent to which the metal-metal and ligand-based vibrational modes couple and, in turn, our ability to observe nu(Mequivalent toM). Computational studies of model systems confirm the assignment of the band as being nu(Mequivalent toM), although the predicted vibrational energies are consistently too high by ca. 7%. The computational results suggest that a nu(Mequivalent toM) band may be present in the published spectra of the M-2(NMe2)(6) pair.