Resonance Raman spectra of. cap alpha. -copper phthalocyanine
Raman spectra of ..cap alpha..-copper phthalocyanine (..cap alpha..-CuPc) were recorded at room temperature and at 10 K with excitation wavelengths between 457 and 714 nm. Resonance enhancement was greatest for modes for which the largest displacements were on either the inner five-membered ring of the isoindole groups or the inner macrocycle and consequently assignment of the bands to modes of the entire molecule was possible by comparison with nickel octaethylporphyrin. Four out of five bands resonant in the Q band region and preresonant near the B band absorption region are totally symmetric modes. B band preresonance occurs more strongly with high-frequency modes. At low temperatures, multimode interactions are reduced and profiles were obtained which can be compared with solution profiles of porphyrins. Both Q/sub x/ and Q/sub y/ 0-0 scattering can be identified and a helper mode is evident. A term enhancement predominates, with B/sub 1g/ and B/sub 2g/ modes enhanced because of a Jahn-Teller distortion of the excited state. The resonance studies, together with electronic absorption spectra and published theoretical studies, confirm that the Q band in ..cap alpha..-CuPc is largely due to an allowed ..pi..-..pi..* transition associated mainly with the macrocycle and inner five-membered rings of the isoindole groups. 25 references, 5 figures, 2 tables.
- Research Organization:
- Univ. of Strathclyde, Glasgow, Scotland
- OSTI ID:
- 5896781
- Journal Information:
- J. Phys. Chem.; (United States), Vol. 90:4
- Country of Publication:
- United States
- Language:
- English
Similar Records
Resonance Raman vibrational analysis of Cu sup II , Fe sup III , and Co sup III porphyrin. pi. cation radicals and their meso-deuteriated analogues
Resonance Raman, infrared, and normal coordinate analysis of free-base tetraphenylbacteriochlorin: A model for bacteriopheophytins
Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
14 SOLAR ENERGY
COPPER COMPLEXES
NORMAL-MODE ANALYSIS
RAMAN SPECTROSCOPY
PHTHALOCYANINES
EXPERIMENTAL DATA
MEDIUM TEMPERATURE
POWDERS
RESONANCE SCATTERING
ROTATIONAL STATES
SILVER
ULTRALOW TEMPERATURE
VIBRATIONAL STATES
COMPLEXES
DATA
DYES
ELEMENTS
ENERGY LEVELS
EXCITED STATES
HETEROCYCLIC COMPOUNDS
INELASTIC SCATTERING
INFORMATION
LASER SPECTROSCOPY
METALS
NUMERICAL DATA
ORGANIC COMPOUNDS
SCATTERING
SPECTROSCOPY
TRANSITION ELEMENT COMPLEXES
TRANSITION ELEMENTS
400301* - Organic Chemistry- Chemical & Physicochemical Properties- (-1987)
140501 - Solar Energy Conversion- Photovoltaic Conversion