Raman spectra and crystal structure of polycrystalline tetramethylammonium salts

Abstract

AbstractThe Raman spectra of eight polycrystalline Me4N+ salts have been measured and are discussed in relation to crystal structures. In most of the salts, several degenerate bands of the cation show splittings due to site symmetries lower than Td. From the spectral shapes in the methyl deformation and stretching region and the intensity ratio of the two NC4 skeletal deformation modes, the extent of cation distortion in each particular salt can be deduced. These distortions are strongest in the halides, whereas no significant crystal field effects are found in the SnCl62− and CdCl3− salts. Anion Raman bands and frequencies of lattice modes are also reported.