One-photon photodetachment of I- in glycerol: spectra and yield of solvated electrons in the temperature range 329 Chandrasekhar, N; Krebs, P; Unterreiner, A-N. Afiliação Chandrasekhar N; Institut für Physikalische Chemie, Lehrstuhl für Molekulare Physikalische Chemie, Universität Karlsruhe (TH), Kaiserstrasse 12, D-76128 Karlsruhe, Germany. J Chem Phys ; 125(16): 164512, 2006 Oct 28. Article em En | MEDLINE | ID: mdl-17092110

ABSTRACT

Solvated electrons in glycerol were generated via a resonant one-photon photodetachment of the charge-transfer-to-solvent (CTTS) band of I- in glycerol (Gl) after irradiation with a 248 nm excimer laser. Optical absorption spectra of solvated electrons (esolv-) in Gl were recorded as a function of temperature (381absorption maximum, homegamax, yields a temperature coefficient d(homegamax)/dT=-(2.67+/-0.07)x10(-3) eV K-1. For solutions with a concentration c(I-) approximately 10(-3)M, the absorbance of esolv- at homegamax increases by a factor of about 65 when the temperature is raised from 329 to 536 K. This effect can be partially explained by a temperature-dependent redshift of the CTTS spectrum of I- in Gl with respect to the laser wavelength. The main contribution to the increasing yield of esolv- is determined by diffusion controlled escape dynamics of the electron in the contact pair (Ie-)solv which is formed very fast during the detachment process. At room temperature no absorption of esolv- (absorbance<1.0x10(-3)) could be observed which is probably a result of an extremely small self-diffusion coefficient of Gl (a factor of 1250 lower than that of water at 298 K). The results are compared with a previous study of I- in ethylene glycol.