Premium
The analysis of unresolved Raman excitation profiles. 2 —Totally Symmetric Fundamentals and Overtones of Some Azo Dyes
Author(s) -
Cataliotti R. S.,
Murgia S. M.,
Paliani G.,
Poletti A.,
Zgierski M. Z.
Publication year - 1985
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.1250160408
Subject(s) - overtone , excitation , chemistry , raman spectroscopy , excited state , azobenzene , resonance (particle physics) , raman scattering , molecular physics , spectral line , chromophore , absorption (acoustics) , atomic physics , photochemistry , optics , molecule , physics , organic chemistry , quantum mechanics , astronomy
Excitation profiles of fundamentals of 4‐nitro‐4′‐diethylaminoazobenzene and 4‐nitro‐6‐cyano‐4′‐( N ‐cyanoethyl‐ N ‐ethylamino)azobenzene reported in the preceding paper are interpreted quantitatively with multi‐mode, three electronic states calculations of Raman intensities. It is demonstrated that the visible absorption spectrum of these azo dyes consists of two overlapping electronic manifolds of nearly equal intensity but with different geometries. Vibrational displacement parameters are determined for five most active totally symmetric vibrations in each dye. The interpretation is supported by observed overtone and combination band intensities. Evidence is presented indicating that inhomogeneous broadening and pre‐resonance scattering from higher excited states play an important role in shaping excitation profiles in the visible region of the spectra.