Temperature Dependence of the Fluorescence Lifetime of Benzene in Cryogenic Solutions.
Abstract
Fluorescence lifetimes for C6D6 in various hydrocarbon solvents have been measured as a function of concentration and temperature. For the solvents ethylene, ethane, and propane it is found that at low concentrations (about 0.3 ppm or about 4 x 10 to the minus 6th power mole/alpha) the fluorescence lifetime is roughly temperature independent (90 < or = T < or = 220K) and equal to the gas phase value of about 150 ns. As the concentration is increased (1 < or = c < or = 100 ppm) the lifetime decreases as temperature is increased reaching a minimum value at about 150K of roughly 70-100 nsec, depending on the concentration. As the temperature is increased from 150K to 220K, the lifetime increases to well over 100 ns. These trends can be understood on the basis of a monomer/excimer kinetic model in which benzene excimers form at low temperature and break apart at high temperature to regenerate the excited state and ground state monomers. In propene and 1-butene solvents, such behavior is not observed most likely due to solvent triplet state quenching of the excited 1B2u benzene monomer.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 28, 1982
- Accession Number
- ADA119858
Entities
People
- Elliot R. Bernstein
- Fangxing Li
- Jung‐Hee Lee
Organizations
- Colorado State University