Spectroscopy and Spectral Analysis, Volume. 34, Issue 4, 1060(2014)
Porphyrins with Different Electron Groups: Spectral and DFT Study
UV-Vis absorption spectra and electrochemical properties of 5-(o-hydroxyphenyl)-10, 15, 20-tri-(p-phenyl)porphyrin (TPPOH) and 5-(o-hydroxyphenyl)-10, 15, 20-tri-(p-methoxyphenyl)porphyrin [(p-OCH3)TPPOH] with different electron groups were investigated by experiments and density functional theory (DFT). Due to the introduction of para-methoxyl group (—OCH3), obvious red shift of 3 nm in the maximum absorbance of the UV-Vis spectra, negative shift in redox potential of (p-OCH3)TPPOH, and the decrease (0.06 eV) in the energy gap (DE) of the frontier highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) (of (p-OCH3)TPPOH occurred as compared to those of TPPOH. The results are due to that electron donating groups of —OCH3 increase the electron density of porphyrin ring in (p-OCH3)TPPOH. Electron distributions of the frontier orbital calculated by DFT showed that the increase in the energy levels of HOMO and LUMO, while the decrease of 0.05 eV in the energy gap. The agreement between experimental result and theoretical value and the further illustration of the mechanism for the spectral change and electrochemical properties provide important bases for the design and application of the porphyrin derivatives with different electron groups.
Get Citation
Copy Citation Text
WU Hai, FAN Su-hua*, ZHANG Hong, LI Hui-quan, YANG Man-qing, ZHANG Cheng-ye. Porphyrins with Different Electron Groups: Spectral and DFT Study[J]. Spectroscopy and Spectral Analysis, 2014, 34(4): 1060
Received: Jul. 15, 2013
Accepted: --
Published Online: Apr. 9, 2014
The Author Email: Hai WU (wuhai317@126.com)