Mapping of upper electronic reaction surfaces by tuned laser photolysis and by absorption and emission spectroscopies

Technical Report · Sat Jul 01 00:00:00 EDT 1989

DOI:https://doi.org/10.2172/5655529· OSTI ID:5655529

Morgan, M A

Potential energy surfaces for photorotamerization of two intramolecularly hydrogen-bonded molecules, o-hydroxybenzaldehyde (OHBA) and methyl salicylate (MS), isolated in cryogenic matrices have been spectroscopically mapped. In addition, the external heavy atom effect of krypton and xenon matrices on the coupling between the S{sub 1} and T{sub 1} surfaces of 4-(dimethylamino)benzonitrile has been examined. Heavy atom matrices are known to increase rates of spin-forbidden processes. The phosphorescence intensity of DMABN increases in krypton and xenon matrices, while the fluorescence intensity, and phosphorescence and fluorescence lifetimes, decrease. These effects are interpreted in terms of a model in which the phosphorescence rate constant increases 300-fold in xenon compared to argon, while the rate constants for intersystem crossing and nonradiative relaxation from the triplet state increase by factors of less than 5. Lifetime measurements in argon matrices doped with heavy atoms indicate that even one heavy atom neighbor has a significant effect on both singlet and triplet lifetimes. 78 refs., 35 figs., 15 tabs.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: DOE/ER
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5655529
• Report Number(s): LBL-27632; ON: DE90000125; TRN: 89-024639
• Resource Relation: Other Information: Thesis (Ph.D.)
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
HYDROXY COMPOUNDS
EXCITED STATES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ABSORPTION SPECTROSCOPY
EMISSION SPECTROSCOPY
ENERGY LEVELS
KINETICS
KRYPTON
MATRICES
PHOSPHORESCENCE
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
SURFACE PROPERTIES
XENON
CHEMICAL REACTIONS
DECOMPOSITION
ELEMENTS
FLUIDS
GASES
LUMINESCENCE
NONMETALS
RARE GASES
SPECTROSCOPY
400201* - Chemical & Physicochemical Properties
400102 - Chemical & Spectral Procedures