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Title: Reevaluation of the gas-phase valence photoelectron spectra of octaethylporphyrin and tetraphenylporphyrin

Abstract

Gas-phase valence photoelectron spectra are reported for 2,3,7,8,12,13,17,18-octaethylporphyrin (OEPH{sub 2}) and 5,10,15,20-tetraphenylporphyrin (TPPH{sub 2}). Comparison of spectra collected with He I and He II sources give an empirical assignment of the relative order of the low-energy {sup 2}A{sub u} and {sup 2}B{sub 1u} ion states in the gas phase. For OEPH{sub 2}, the first ionization at 6.24 eV is assigned to the {sub 2}A{sub u} ion state, with the {sup 2}B{sub 1u} ionization located 0.25 eV to higher energy. The photoelectron spectrum reported here is quite different from the previously reported spectrum of OEPH{sub 2}. The first ionization of TPPH{sub 2} is assigned to the {sup 2}B{sub 1u} ion state, with the {sup 2}A{sub u} ionization 0.27 eV to higher energy. The reversal of the ordering of the first two ionizations of OEPH{sub 2} and TPPH{sub 2} is due to the different site of the substituents and the different nodal properties of the porphyrin orbitals.

Authors:
; ; ;
Publication Date:
Research Org.:
Univ. of Arizona, Tucson, AZ (US)
Sponsoring Org.:
USDOE; National Science Foundation (NSF); National Institutes of Health (NIH)
OSTI Identifier:
20000072
DOE Contract Number:  
FG03-95ER14574
Resource Type:
Journal Article
Journal Name:
Inorganic Chemistry
Additional Journal Information:
Journal Volume: 38; Journal Issue: 18; Other Information: PBD: 6 Sep 1999; Journal ID: ISSN 0020-1669
Country of Publication:
United States
Language:
English
Subject:
40 CHEMISTRY; PORPHYRINS; PHOTOELECTRON SPECTROSCOPY; VALENCE; ELECTRONS

Citation Formats

Gruhn, N.E., Lichtenberger, D.L., Ogura, Hiroshi, and Walker, F.A. Reevaluation of the gas-phase valence photoelectron spectra of octaethylporphyrin and tetraphenylporphyrin. United States: N. p., 1999. Web. doi:10.1021/ic990279o.
Gruhn, N.E., Lichtenberger, D.L., Ogura, Hiroshi, & Walker, F.A. Reevaluation of the gas-phase valence photoelectron spectra of octaethylporphyrin and tetraphenylporphyrin. United States. doi:10.1021/ic990279o.
Gruhn, N.E., Lichtenberger, D.L., Ogura, Hiroshi, and Walker, F.A. Mon . "Reevaluation of the gas-phase valence photoelectron spectra of octaethylporphyrin and tetraphenylporphyrin". United States. doi:10.1021/ic990279o.
@article{osti_20000072,
title = {Reevaluation of the gas-phase valence photoelectron spectra of octaethylporphyrin and tetraphenylporphyrin},
author = {Gruhn, N.E. and Lichtenberger, D.L. and Ogura, Hiroshi and Walker, F.A.},
abstractNote = {Gas-phase valence photoelectron spectra are reported for 2,3,7,8,12,13,17,18-octaethylporphyrin (OEPH{sub 2}) and 5,10,15,20-tetraphenylporphyrin (TPPH{sub 2}). Comparison of spectra collected with He I and He II sources give an empirical assignment of the relative order of the low-energy {sup 2}A{sub u} and {sup 2}B{sub 1u} ion states in the gas phase. For OEPH{sub 2}, the first ionization at 6.24 eV is assigned to the {sub 2}A{sub u} ion state, with the {sup 2}B{sub 1u} ionization located 0.25 eV to higher energy. The photoelectron spectrum reported here is quite different from the previously reported spectrum of OEPH{sub 2}. The first ionization of TPPH{sub 2} is assigned to the {sup 2}B{sub 1u} ion state, with the {sup 2}A{sub u} ionization 0.27 eV to higher energy. The reversal of the ordering of the first two ionizations of OEPH{sub 2} and TPPH{sub 2} is due to the different site of the substituents and the different nodal properties of the porphyrin orbitals.},
doi = {10.1021/ic990279o},
journal = {Inorganic Chemistry},
issn = {0020-1669},
number = 18,
volume = 38,
place = {United States},
year = {1999},
month = {9}
}