Density functional theory studies on the Raman and IR spectra of meso-tetraphenylporphyrin diacid.
Spectrochim Acta A Mol Biomol Spectrosc
; 62(4-5): 850-62, 2005 Dec.
Article
en En
| MEDLINE
| ID: mdl-16303631
ABSTRACT
The vibrational spectra of meso-tetraphenylporphyrin diacid (H4TPP2+) have been studied with the density functional theory. Raman and IR spectra of H4TPP2+ and its N-deuterated analogue (D4TPP2+) are measured and compared with the computational results. Complete assignments of observed IR and Raman bands were proposed on the bases of calculation results. The DFT calculations reproduce 140 observed fundamentals with the RMS 8.6 cm-1. The computational as well as the experimental results reveal that the saddle-distortion of porphyrin macrocycle for the diacid leads to a significant effect on its vibrational spectra. Especially, several out-of-plane skeletal modes, which were either unobserved or very weak in the Raman spectra of CuTPP and H2TPP, are activated in the Raman spectra of the diacids. In addition, enhancement for the Raman bands of phenyl CC stretching modes were observed and attributed to the conjugation effect of pi-systems of the phenyl and the porphyrinato macrocycles.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Porfirinas
/
Espectrofotometría Infrarroja
/
Espectrometría Raman
/
Ácidos
/
Modelos Químicos
Idioma:
En
Revista:
Spectrochim Acta A Mol Biomol Spectrosc
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
2005
Tipo del documento:
Article