Photolytical Property of Dibutyl phthalate (DBP)

In this paper, the transient absorbance spectra and kinetics characteristics of DBP are studied in 266 nm laser flash photolysis with three different mixed solvents. The transient species, assigned to DBP excited triplet, with maximum absorption at 300 nm were observed in deoxidation system meanwhile its decay process accelerated obviously in O₂-statured system. By changing the concentration of DBP a series of observed decay rate constants were obtained and the self-quenching rate constants of DBP excited triplet were determined to be 4.5 × 10⁷, 3.0 × 10⁷ and 2.2 × 10⁷ mol^-1 s^-1 L for ethanol/water, methanol/water and acetonitrile/water systems and self-decay rate constants to be 0.96 × 10⁵ s^-1, 1.25× 10⁵ s^-1 and 1.33 × 10⁵ s^-1, respectively. It revealed that the properties of DBP excited triplet have some relationship with the dielectric constants of solvents.