Calculation and interpretation of the vibrational spectra of methyl thiocyanate CH3SCN and deuteromethyl thiocyanate CD3SCN

An X-ray crystallographic, Raman, and infrared spectral study of crystalline potassium uranyl carbonate, K4UO2(CO3)3

“…These two modes can be considered pure, involving little or no mixing (9). On the other hand the v, deformation mode, nominally expected in the 200 cm-' region, involves changes in the oxygen-uranium-carbonate angles and thus is strongly coupled with low frequency external modes of the carbonate ions (9). No single frequency can be assigned and discussion is left until the lattice modes are considered.…”

“…All modes are mixed because of the low site symmetry and thus unique assignments are impossible. Furthermore the deformation of UOZ2+ (which involves a dipole change and hence appreciable infrared activity) is accompanied by motions of the carbonate ions and that internal mode cannot be uniquely designated (9). However, it is reasonable to attribute the grouping of bands from 240 to 320 cm-I largely to motions involving uranyl deformation, bands from 150 to 240 cm-I to carbonate librations and bands from 100 to 150 cm-' to uranyl librations since the moment of inertia of UOZ2+ is larger than that of the carbonates.…”