Laser flash photolysis study of (2-anthryl)ethylenes. Triplet-related photophysical behaviors

Journal Article · Thu Mar 15 04:00:00 EST 1984 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j150650a030· OSTI ID:6550020

Wismontski-Knittel, T; Das, P K

The triplet-state photophysical behaviors of three trans-1,2-diarylethylenes with a phenyl, 2-naphtyl, or 2-thienyl group as one substituent and a 2-anthryl as the other have been studied by laser flash photolysis and pulse radiolysis. The triplets have been generated by energy transfer under sensitized conditions, direct intersystem crossing (in bromobenzene), and assisted intersystem crossing in the presence of such singlet quenchers as oxygen, ethyl iodide (EtI), di-tert-butyl nitroxide (DTBN), and N,N-dimethylaniline (DMA). The absorption spectra of the triplets are sharp, intense, and well resolved and display two major band systems at 400-500 and 550-650 nm, respectively. The observed triplet lifetimes (tau/sub T/) are in the range 15-120 ..mu..s. On the basis of the data concerning triplet-triplet (T-T) spectra, tau/sub T/'s, triplet quenching by azulene and di-tert-butyl nitroxide, and Stern-Volmer behavior for triplet formation via exciplexes with N,N-dimethylaniline, the triplets are assignable to predominantly one conformeric species, or multiple species with indistinguishable spectral and kinetic behaviors, with the excitation energy in either case being localized primarily on the anthracene moiety. In the case of 1-(2-thienyl)-2-(2-anthryl)ethylene, triplet-related formation and decay processes with associated lifetimes 100-120 ns are observed at the initial stage following the laser excitation; these are tentatively attributed to intramolecular relaxation in the initially formed triplet conformers in the form of rotation of aryl groups about quasi-single bonds. 5 figures, 3 tables.

• Research Organization: Univ. of Notre Dame, IN
• OSTI ID: 6550020
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 88:6; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
400500 -- Photochemistry
ABSORPTION SPECTRA
ALKENES
AMINES
AROMATICS
BENZENE
CHALCOGENIDES
CHEMICAL REACTIONS
CONDENSED AROMATICS
DATA
DECOMPOSITION
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EXCITATION
EXCITED STATES
EXPERIMENTAL DATA
HALOGENATED ALIPHATIC HYDROCARBONS
HYDROCARBONS
INFORMATION
IODINATED ALIPHATIC HYDROCARBONS
LASER RADIATION
NITROGEN COMPOUNDS
NITROGEN OXIDES
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
ORGANIC SOLVENTS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
RADIATIONS
REACTION INTERMEDIATES
SOLVENTS
SPECTRA
STRUCTURAL CHEMICAL ANALYSIS
TIME DEPENDENCE
VIBRATIONAL STATES