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Spectroscopic characterization of cadion: UV–vis, resonance Raman and DFT calculations of a versatile metal complexing agent
Author(s) -
Lepre Luiz F.,
Inoue Fabiana,
Corio Paola,
Santos Paulo S.,
Ando Rômulo A.
Publication year - 2013
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.4228
Subject(s) - raman spectroscopy , triazene , chemistry , resonance raman spectroscopy , moiety , metal , resonance (particle physics) , spectroscopy , density functional theory , ultraviolet visible spectroscopy , photochemistry , absorption spectroscopy , characterization (materials science) , analytical chemistry (journal) , computational chemistry , stereochemistry , organic chemistry , materials science , nanotechnology , optics , physics , quantum mechanics , particle physics
The spectroscopic characterization of cadion or 1‐(4‐nitrophenyl)‐3‐(4‐phenylazophenyl)triazene, its anionic species and its complexes with Hg 2+ , Cd 2+ and Ni 2+ in DMSO solution is presented. Resonance Raman (RR) and UV–vis spectroscopy were the techniques of choice with results supported by density functional theory calculations. As previously reported, the UV–vis data indicate distinct absorption spectra for the five species mentioned, allowing for spectrophotometric metal differentiation. In order to understand the electronic spectra of such species, we performed a detailed RR investigation, where the spectral profiles revealed the vibrational modes mainly involved in the chromophoric moieties. The distinct enhancement profile observed for each species suggests that the charge transfer from the π‐system to the electron withdrawing NO 2 group is modulated by the electron donating triazene moiety, depending on the metal attached. The results reported herein show that RR spectroscopy can be potentially used in the metal detection of multicomponent samples by the proper choice of the excitation wavelength. Copyright © 2012 John Wiley & Sons, Ltd.