Grabner G, Getoff N, Gantchev T, Angelov D, Shopova M
Institut für Theoretische Chemie und Strahlenchemie, Universität Wien, Vienna, Austria.
Photochem Photobiol. 1991 Nov;54(5):673-81. doi: 10.1111/j.1751-1097.1991.tb02074.x.
Nanosecond (lambda exc = 266, 355 and 532 nm) and picosecond (lambda exc = 355 nm) laser flash photolysis of hematoporphyrin (Hp) was performed in neutral (pH 7.4) and alkaline (pH 12) aqueous solution, as well as in the presence of 0.1% Triton X-100. The dependence of the yield of photoproduced hydrated electrons (e-aq) on laser pulse energy was studied over a wide range of energies (0.2 to greater than 1000 mJ cm-2). The results show that e-aq are predominantly formed in a two-photon process at lambda exc = 266 and 355 nm. One-photon quantum yields are higher at lambda exc = 266 nm than at lambda exc = 355 nm. Both one-photon and two-photon pathways are less efficient at higher Hp concentration, reflecting the influence of Hp self-aggregation. Two-photon e-aq formation is more efficient when 30 ps pulses are used for excitation, as compared to 10 ns pulses. No e-aq could be detected at lambda exc = 532 nm. Nanosecond pulse-induced transient spectra obtained at pH 7.4 are also discussed.
在中性（pH 7.4）和碱性（pH 12）水溶液中，以及在0.1% Triton X - 100存在的情况下，对血卟啉（Hp）进行了纳秒级（激发波长λexc = 266、355和532 nm）和皮秒级（激发波长λexc = 355 nm）的激光闪光光解。在很宽的能量范围（0.2至大于1000 mJ cm-2）内研究了光生水合电子（e-aq）产率对激光脉冲能量的依赖性。结果表明，在激发波长λexc = 266和355 nm时，e-aq主要通过双光子过程形成。在激发波长λexc = 266 nm时单光子量子产率高于激发波长λexc = 355 nm时。在较高的Hp浓度下，单光子和双光子途径的效率都较低，这反映了Hp自聚集的影响。与10 ns脉冲相比，当使用30 ps脉冲进行激发时，双光子e-aq的形成更有效。在激发波长λexc = 532 nm时未检测到e-aq。还讨论了在pH 7.4下获得的纳秒脉冲诱导的瞬态光谱。
