Fourier transform fluorescence and phosphorescence of porphine in rare gas matrices

Journal Article · Thu Mar 07 04:00:00 EST 1991 · Journal of Physical Chemistry; (USA)

DOI:https://doi.org/10.1021/j100158a015· OSTI ID:5680250

Radziszewski, J G; Waluk, J; Nepras, M; Michl, J ^[1]

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1. Univ. of Texas, Austin (USA)

Matrix-isolated free-base porphine and its deuterated analogues show highly resolved intense fluorescence in neon, with evidence of strong b{sub 1g} vibronic activity, and highly resolved intense phosphorescence in xenon, dominated by totally symmetric vibrations. Triplet lifetimes were determined from T-T absorption decay, which revealed a new band at 310 nm. It was concluded that the heavy-atom enhancement of the T{sub 1} {yields} S{sub 0} radiative rate is dramatic. Both emissions exhibit site structure, and single-site spectra were obtained upon narrow-bandwidth excitation. The T{sub 1} {yields} S{sub 0} emission site pattern is identical with that of S{sub 1} {yields} S{sub 0} emission and S{sub 1} {l arrow} S{sub 0} absorption and totally different from that of S{sub 2} {l arrow} S{sub 0} absorption, suggesting that T{sub 1} and S{sub 1} are both Q{sub x} and have a common orbital origin, contrary to the currently accepted assignment. The implications of the results for the mechanism of the photoinduced double proton transfer in free-base porphine are considered. All the results are compatible with the proposal that the isomerization occurs in T{sub 1} in a stepwise fashion through the cis isomer. The advantages of interferometric recording of highly resolved visible and near-IR emission spectra are pointed out.

• OSTI ID: 5680250
• Journal Information: Journal of Physical Chemistry; (USA), Journal Name: Journal of Physical Chemistry; (USA) Vol. 95:5; ISSN 0022-3654; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102* -- Chemical & Spectral Procedures
CARBOXYLIC ACIDS
DATA
DATA ANALYSIS
ELEMENTS
EMISSION SPECTROSCOPY
EXPERIMENTAL DATA
FLUIDS
FLUORESCENCE SPECTROSCOPY
FOURIER TRANSFORM SPECTROMETERS
GASES
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
INFORMATION
LUMINESCENCE
MATRIX ISOLATION
MEASURING INSTRUMENTS
NONMETALS
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOSPHORESCENCE
PORPHYRINS
RARE GASES
SPECTROMETERS
SPECTROSCOPY