Resonance Raman spectra of metallooctaethylporphyrin cation radicals with a/sub 1u/ and a/sub 2u/ orbital character
Resonance Raman (RR) spectra are reported for radical cations of M/sup II/OEP (OEP = octaethylporphyrin; M = Zn, Mg, Ni, Cu) and for the perchlorate and bromide salts of (Co/sup III/OEP)/sup +/, produced by electrochemical and/or chemical oxidation. The enhancement patterns obtained with B (4067 A) and Q (5682 A) band excitation (except M = Zn and Mg, for which fluorescence overwhelms the Q band RR spectra) permitted assignment of most of the porphyrin skeletal modes above 1000 cm/sup -1/, and frequency shifts relative to the unoxidized porphyrins have been cataloged. Those radicals, magnesium(II), zinc(II), and cobalt(III) bromides, whose EPR spectra have been assigned on the basis of electron removal from an a/sub lu/ molecular orbital show a common pattern of shifts, while those with a/sub 2u/-type EPR spectra, nickel(II) and cobalt(III) perchlorates, show a different pattern. The Cu/sup II/ radical, whose visible absorption spectrum resembles that of other a/sub 2u/ radicals, likewise has an a/sub 2u/ RR frequency shift pattern. The largest shifts are shown by the most prominent RR bands in the B-band-excited spectra, nu/sub 4/ (C/sub a/N breathing, primarily) and nu/sub 2/ (C/sub b/C/sub b/ breathing, primarily).
- Research Organization:
- Princeton Univ., NJ
- DOE Contract Number:
- AC02-81ER10861
- OSTI ID:
- 5583681
- Journal Information:
- J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 90:15; ISSN JPCHA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
ALKALINE EARTH METAL COMPLEXES
CATIONS
CHARGED PARTICLES
COMPLEXES
COPPER COMPLEXES
DATA
ENERGY LEVELS
EXCITED STATES
EXPERIMENTAL DATA
INELASTIC SCATTERING
INFORMATION
IONS
LASER SPECTROSCOPY
MAGNESIUM COMPLEXES
NICKEL COMPLEXES
NORMAL-MODE ANALYSIS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANOMETALLIC COMPOUNDS
RADICALS
RAMAN SPECTROSCOPY
RESONANCE SCATTERING
SCATTERING
SPECTROSCOPY
TRANSITION ELEMENT COMPLEXES
VIBRATIONAL STATES
ZINC COMPLEXES