Remote Sensitized Photoisomerization via Through-Bond TripletâTriplet Energy Transfer Mediated by a Salt Bridge in a Supramolecular Dyad
作者:Lei Han、Hengxing Wei、Shayu Li、Jinping Chen、Yi Zeng、Ying-Ying Li、Yongbin Han、Yi Li、Shuangqing Wang、Guoqiang Yang
DOI:10.1002/cphc.200900556
日期:2010.1.18
BD salt bridge system. The triplet–triplet energy transfer process proceeds with efficiencies of approximately 0.87, 0.98 and the rate constants 1.8×103 s−1, and 1.3×107 s−1 at 77 K and room temperature, respectively. The mechanism for the triplet–triplet energy transfer is proposed to proceed via a “through‐bond” electron exchange process, and the non‐covalent bonds amidinium‐carboxylate salt bridge
构造了一个超分子二倍体BP-(ami-羧酸盐)-NBD,其中二苯甲酮(BP)和降冰片二烯(NBD)通过am-羧酸盐盐桥连接。检查组装的BP-((-羧酸盐)-NBD二聚体的光物理和光化学性质。BP发色团的磷光通过盐桥被BP-(ami-羧酸盐)-NBD中的NBD基团有效地淬灭。时间分辨光谱测量表明,由于NBD组的猝灭,BP-(-羧酸盐)-NBD中BP三重态的寿命缩短了。BP发色团的选择性激发导致NBD基团异构化为四环烷(QC)。所有这些观察结果表明,三重态-三重态能量传递在BP-(ami-羧酸盐)-NBD盐桥系统中有效发生。三重态-三重态能量传递过程的效率约为0.87、0.98,速率常数为1.8×10在77 K和室温下分别为3 s -1和1.3×10 7 s -1。提出三重态-三重态能量转移的机制是通过“键合”电子交换过程进行的,非共价键am化羧酸盐盐桥可以有效地介导三重态-三重态能量转移过程,以进行光化学转化。