Enhancement of Photodriven Charge Separation by Conformational and Intermolecular Adaptations of an Anthracene–Perylenediimide–Anthracene Triad to an Aqueous Environment
Enhancement of Photodriven Charge Separation by Conformational and Intermolecular Adaptations of an Anthracene–Perylenediimide–Anthracene Triad to an Aqueous Environment
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DOI：
10.1021/jp403285k
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发表时间：
2013-06
影响因子：
3.7
通讯作者：
Mustafa Supur;Y. Sung;Dongho Kim;S. Fukuzumi
中科院分区：
文献类型：
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作者：
Mustafa Supur;Y. Sung;Dongho Kim;S. Fukuzumi
利用时间分辨激光光谱技术研究了由蒽和苝二酰亚胺（An 2 PDI）组成的电子给体-受体-给体三元组在不同介质中的光诱导电子转移动力学。芳族组分通过在三元组中含有亲水性季铵接头的柔性接头连接。在MeOH中，其中An 2 PDI完全溶解，没有电子转移产物中观察到的瞬态吸收测量后，由于快速的背电子转移的蒽和PDI的激发。由PDI单重激发态的猝灭估算出三重态在甲醇中的电荷分离速率为1.2 × 1010 s-1。与此相反，在水中电子转移产物的形成是明显的，并且在激发An 2 PDI的选定组分的过程中，电子转移速率比在MeOH中的速率快200倍（2.5 × 1012 s-1）。从时间分辨数据可以得出结论，构象差异是由分子结构决定的。
Photoinduced electron-transfer dynamics of an electron donor–acceptor–donor triad, consisting of anthracenes and perylenediimide (An2PDI), were investigated in different media by using time-resolved laser spectroscopic techniques. The aromatic components are attached by flexible linkers containing hydrophilic quaternary ammonium joints in the triad. In MeOH, in which An2PDI dissolves completely, no electron-transfer products were observed in the transient absorption measurements after the excitation of anthracenes and PDI because of the rapid back-electron transfer. The charge-separation rate of the triad in MeOH was estimated as 1.2 × 1010 s–1 from the quenching of the singlet-excited state of PDI. In contrast, the formation of electron-transfer products was evident in water, and the electron-transfer rate was 200 times faster than the rate in MeOH in the course of the excitations of the selected components of An2PDI (2.5 × 1012 s–1). It is concluded from the time-resolved data that the conformational di...