Open AccessFine structure of the Raman lines of carbon tetrachloride
Author(s) -
A. C. Menzies
Publication year - 1939
Publication title -
proceedings of the royal society of london. series a, mathematical and physical sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.814
H-Index - 135
eISSN - 2053-9169
pISSN - 0080-4630
DOI - 10.1098/rspa.1939.0091
Subject(s) - raman spectroscopy , chemistry , normal mode , molecule , resonance (particle physics) , singlet state , symmetry (geometry) , analytical chemistry (journal) , nuclear magnetic resonance , excited state , atomic physics , physics , optics , vibration , mathematics , geometry , organic chemistry , quantum mechanics , chromatography
Assuming first of all for simplicity that the four chlorine atoms are identical, the greatest symmetry the CCl4 molecule could have isTd . This would lead us to anticipate four fundamentals,v 1 ,v 2 ,v 3 ,v 4 belonging to normal modesA 1 ,E ,F 2 ,F 2 , respectively, using Placzek’s (1934) nomenclature.A 1 is the total symmetric normal mode, and sov 1 is polarized in the Raman effect, and inactive in the infra-red.A 1 is a singlet mode.E is a doublet mode andv 2 is depolarized in the Raman effect, while it is inactive in the infra-red.F 2 is a triplet mode andv 3 andv 4 are depolarized in the Raman effect and are also active in the infra-red. If the Raman spectrum of CCl4 is examined under coarse dispersion, lines are observed at 217, 314, 459 cm.-1 , identified asv 2 ,v 4 andv 1 respectively. Two at 760 and 790 cm.-1 are usually regarded as the result of resonance degeneracy betweenv 3 and (v 1 +v 4 ), both in the modeF 2 .