Photodimerization Kinetics of a Styrylquinoline Derivative in Langmuir-Blodgett Monolayers Monitored by Second Harmonic Generation
Photodimerization Kinetics of a Styrylquinoline Derivative in Langmuir-Blodgett Monolayers Monitored by Second Harmonic Generation
复制标题
通过二次谐波产生监测 Langmuir-Blodgett 单分子层中苯乙烯基喹啉衍生物的光二聚动力学
DOI：
10.1021/acs.jpcc.7b08409
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发表时间：
2017-10-26
影响因子：
3.7
通讯作者：
Lu, Zhou
中科院分区：
文献类型：
--
作者：
Ma, Yingxue;Xie, Yu;Lu, Zhou
为了探讨表面堆积密度对界面光化学动力学的影响，采用表面选择性二次谐波发生（SHG）技术研究了朗缪尔-布洛杰特（LB）单层内苯乙烯基喹啉烷氧基衍生物的双光子诱导[2 + 2]光环加成反应的动力学。激光功率依赖性实验表明，这种界面光二聚反应是一级反应，这意味着光激发是限速步骤。有趣的是，不同表面堆积密度下光二聚动力学的比较显示出反应速率常数的非单调分布，这可归因于拓扑化学机制和空间位阻综合作用的结果。原子力显微镜测量和理论计算也被用来帮助理解[2 + 2]光环加成机制。这项工作中提出的结果表明，表面堆积密度起着......
To explore the influence of surface packing densities on the interfacial photochemical kinetics, the surface-selective second harmonic generation (SHG) technique was used to investigate the kinetics of two-photon induced [2 + 2] photocycloadditions of a styrylquinoline alkoxy derivative within the Langmuir–Blodgett (LB) monolayers. The laser power dependence experiment revealed that this interfacial photodimerization is a first-order reaction, which implies that the photoexcitation is the rate-limiting step. Interestingly, a comparison of photodimerization kinetics at different surface packing densities shows a nonmonotonic distribution of reaction rate constants, which can be attributed to a result of combined effects of the topochemical mechanism and steric hindrance. The atomic force microscopy measurements and theoretical calculations were also employed to help understand the [2 + 2] photocycloaddition mechanisms. The results presented in this work demonstrate that the surface packing density plays an...