Time-dependent radiolytic yields at room temperature and temperature-dependent absorption spectra of the solvated electrons in polyols

The molar extinction coefficients at the absorption maximum of the solvated electron spectrum have been evaluated to be 900,970,and 1000 mol^(-1).m^2 for 1,2-ethanediol (12ED),1,2-propanediol (12PD),and 1,3-propanediol (13PD),respectively.These values are two-third or three-fourth of the value usually reported in the published report. Picosecond pulse radiolysis studies have aided in depicting the radiolytic yield of the solvated electron in these sol- vents as a function of time from picosecond to microsecond.The radiolytic yield in these viscous solvents is found to be strongly different from that of the water solution.The temperature dependent absorption spectra of the solvated electron in 12ED,12PD,and 13PD have been also investigated.In all the three solvents,the optical spectra shift to the red with increasing temperature.While the shape of the spectra does not change in 13PD,a widening on the blue side of the absorption band is observed in 12ED and 12PD at elevated temperatures.

Kinetics study of the solvated electron decay in THF using laser-synchronised picosecond electron pulse

Picosecond pulse radiolysis of neat tetrahydrofuran (THF) shows a fast decay of the solvated electron within 2.5ns.The decay of the solvated electron observed at 790nm is because of spur reaction.A numerical simulation using time dependent Smoluchowski equation containing a sink term with a distance dependent reaction rate is used to fit the pulse-probe data and shows that the geminate reaction can proceed at long distance in this low polar solvent.

溶剂化电子研究的前沿进展

溶剂化电子是自然界中最小的阴离子和最强的还原性粒子,也是辐射化学反应过程中重要的活性物质。溶剂化电子的研究将为溶液自由基反应、乏燃料后处理中溶剂与萃取剂的辐射化学、生命过程的电荷转移与电荷传输等领域提供关键信息,因此是有机化学、无机化学、辐射化学和放射生物学研究中的重要课题。近年来,随着短脉冲激光技术的新一轮革命,有关溶剂化电子的研究迎来了新的一轮爆发增长期。为此,本文力图概述当前溶剂化电子研究的前沿进展,主要内容涉及溶剂化电子结合能的测定、溶剂化电子的表面态以及预溶剂化电子和准自由电子与核苷酸分子的反应动力学等。