Laser pulse-probe study of triplet exciton processes in poly(N-((vinyloxy)carbonyl)carbazole) and its monomeric analogue

Journal Article · Thu Apr 09 04:00:00 EDT 1987 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100292a042· OSTI ID:6539637

Burkhart, R D; Boileau, S; Boivin, S

The triplet photophysical properties of poly(N-((vinyloxy)carbonyl)carbazole) (PFCZ) and of its monomeric analogue (MFCZ) have been examined in rigid solutions of 2-methyltetrahydrofuran at 77 K. The molar absorptivity of the triplets was found to be 3.1 x 10/sup 4/ M/sup -1/ cm/sup -1/ for MFCZ at 395 nm and 1.1 x 10/sup 4/ M/sup -1/ cm/sup -1/ for PFCZ at 430 nm. The triplet-triplet absorption spectrum for the polymer is broader and has a lambda/sub max/ shifted to longer wavelength compared with that of the monomeric species. Quantum yields for triplet formation are essentially the same for both compounds (0.021 for PFCZ and 0.033 for MFCZ), but the radiative rate constant for phosphorescence of PFCZ is larger (0.023 s/sup -1/) than for MFCZ (0.013 s/sup -1/). The specific rate constants for radiationless transitions from T/sub 1/ to the ground state are 0.14 s/sup -1/ for MFCZ and 0.15 s/sup -1/ for PFCZ. The specific rate constant for triplet-triplet annihilation in PFCZ was determined subject to data analyses assuming intramolecular triplet exciton migration with either one or three degrees of freedom. Only the system assuming three degrees of freedom yields physically realistic results and leads to a migration frequency of 10/sup 4/ s/sup -1/. This is in agreement with a value for this frequency found for poly(vinylbenzophenone) based on a phosphorescence quenching method.

• Research Organization: Univ., Nevada, Reno
• DOE Contract Number: FG08-84ER45107
• OSTI ID: 6539637
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 91:8; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500* -- Photochemistry
ABSORPTION SPECTROSCOPY
ABSORPTIVITY
AROMATICS
AZAARENES
AZOLES
CARBAZOLES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
DE-EXCITATION
ENERGY LEVELS
ENERGY TRANSFER
ENERGY-LEVEL TRANSITIONS
EXCITED STATES
EXCITONS
GROUND STATES
HETEROCYCLIC COMPOUNDS
KINETICS
LOW TEMPERATURE
LUMINESCENCE
MONOMERS
MULTIPLETS
OPTICAL PROPERTIES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOSPHORESCENCE
PHOTOCHEMICAL REACTIONS
PHYSICAL PROPERTIES
POLYMERS
QUASI PARTICLES
RADIATIONLESS DECAY
REACTION KINETICS
SPECTROSCOPY
TRIPLETS