密度泛函理论研究5-单苯基卟啉分子的几何结构和拉曼光谱

DFT Study on the Geometric Structure and Raman Spectrum of meso-monophenylporphyrin (H2MPP)

ZHANG Ying-Hui

,

RUAN Wen-Juan

,

WU Yang

1.

Department of Chemistry, Nankai University, Tianjin 300071

Received Date:

16 May 2005

Available Online:

15 December 2005

Abstract:

The geometric structure and Raman frequencies of meso-monophenylporphyrin (H2MPP) were studied by density-functional-theory (DFT). The calculation indicates that meso-monophenyl substitution induces larger distortion to meso-position than to pyrrole ring. All calculated frequencies were scaled with a single factor of 0.971, which gives acceptable results compared with experimental data (the RMS is 6.7 cm-1). The measured Raman spectra were discussed and the assignment of in-plane vibrational normal mode of porphyrin ring was given on the basis of theoretical calculation. Further analysis indicates the splits of some in-plane vibrational normal modes of porphyrin ring (for instance ν6, ν20, ν24, and ν32 mode), which was attributed to the diversification of the structure around Cm atoms and pyrrole structure induced by meso-monophenyl substitution.

Key words:

DFT;meso-monophenylporphyrin;Raman spectrum