Charge-transfer quenching of singlet oxygen O2(1Δg) by amines and aromatic hydrocarbons
Charge-transfer quenching of singlet oxygen O2(1Δg) by amines and aromatic hydrocarbons
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DOI：
10.1021/jp982326o
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发表时间：
1998-09-17
影响因子：
2.9
通讯作者：
Jardon, P
中科院分区：
文献类型：
--
作者：
Darmanyan, AP;Jenks, WS;Jardon, P
在乙腈和苯中测定了29种胺和芳烃对1.27 μ m处单线态氧O-2（（1）δ（g））发光的猝灭速率常数。猝灭发生通过可逆的电荷转移与激基复合物的形成与部分（Δ近似0.2 esu）电子转移。钙离子激基复合物系统间穿越速率常数的估计。10（10）s（-1），并注意到随着激基复合物能量的增加适度降低。数据预测和证实，电荷转移在单线态氧的非辐射衰变中起着重要的作用，在溶剂中难以氧化的甲苯-d（8）和均三甲苯。N，N，N '，N'-四甲基对苯二胺在D2 O中几乎完全通过电子转移猝灭O-2（（1）Delta（g）），但在其它溶剂中未观察到电子转移。
The quenching rate constants of singlet oxygen O-2((1)Delta(g)) luminescence at 1.27 mu m by 29 amines and aromatic hydrocarbons were measured in acetonitrile and benzene. Quenching occurs via reversible charge transfer with the formation of an exciplex with a partial (delta approximate to 0.2 esu) electron transfer. An estimate of the intersystem-crossing rate constant for the exciplex of ca. 10(10) s(-1) is obtained, and a modest decrease with increasing exciplex energy is noted. The data predict and it is confirmed that charge transfer plays a significant role in the nonradiative decay of singlet oxygen in solvents as difficult to oxidize as toluene-d(8) and mesitylene. It is also confirmed that N,N,N',N'-tetramethyl-p-phenylene diamine quenches O-2((1)Delta(g)) nearly exclusively by full electron transfer in D2O, but electron transfer is not observed in other solvents.