Vibrational spectra of halopentacarbonylmanganese(I) derivatives

The solid-state infrared (i.r.) and laser Raman spectra of the halopentacarbonylmanganese(I) derivatives, Mn(CO)5X (X = Cl, Br,and I), have been recorded in the C—O stretching and the low frequency (700–33 cm−1) regions. The i.r. overtone and combination spectra recorded in the regions 2800–2250 and 1350–700 cm−1 have been used to help in the assignment of some of the low frequency fundamentals. The solid-state i.r. and laser Raman spectra of the dimeric halotetracarbonylmanganese(I) derivatives, [Mn(CO)4X]2 (X = Br and I), have been recorded in the C—O stretching and the low frequency regions for comparative purposes and shown to be consistent with the expected D2h symmetry of the molecules.