Formation of a Supramolecular Porphyrin-Spacer-Acceptor Ternary Complex and Intracomplex Electron Transfer
Formation of a Supramolecular Porphyrin-Spacer-Acceptor Ternary Complex and Intracomplex Electron Transfer
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DOI：
10.1021/jp027165
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发表时间：
2003
影响因子：
2.9
通讯作者：
J. Otsuki;Masayuki Takatsuki;M. Kaneko;H. Miwa;T. Takido;M. Senō;K. Okamoto;H. Imahori;M. Fujitsuka;Y. Araki;O. Ito;S. Fukuzumi
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文献类型：
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作者：
J. Otsuki;Masayuki Takatsuki;M. Kaneko;H. Miwa;T. Takido;M. Senō;K. Okamoto;H. Imahori;M. Fujitsuka;Y. Araki;O. Ito;S. Fukuzumi
开发了一种新的双位间隔物N-丙基异烟肼，通过间隔物与锌的轴向配位以及间隔物与受体之间的盐桥作用，组装了锌-四苯基卟啉-间隔物-受体(3，4-二硝基苯甲酸)三元超分子络合物。通过1HHMR和UV-Vis光谱对三元络合物的形成进行了探讨。在二氯甲烷中形成的三元络合物的总缔合常数为1.9×108M-2。稳态荧光测量证实，荧光几乎完全被三元络合物中的电子受体猝灭。三元络合物中的电子受体也猝灭了ZnTPP的三重态激发态。三元络合物也在乙腈中形成，荧光猝灭，络合物内猝灭速率常数为1.9×109 S~(-1)。光诱导的复合体内电子转移是荧光猝灭和三重态漂白的可能机制。
A new ditopic spacer, N-propylisonicotinamidine, has been developed to assemble a ternary supramolecular complex, zinc-tetraphenylporphyrin (ZnTPP)-spacer-acceptor (3,4-dinitrobenzoic acid), via an axial coordination of the spacer to ZnTPP and a salt bridge interaction between the spacer and acceptor. Formation of this ternary complex was probed by 1 H HMR and UV-vis spectroscopy. The ternary complex is formed with an overall association constant of 1.9 x 10 8 M - 2 in dichloromethane. The fluorescence is nearly completely quenched by the electron acceptor in the ternary complex as confirmed by the steady-state fluorescence measurements. The triplet excited state of ZnTPP is also quenched by the electron acceptor in the ternary complex. The ternary complex is also formed in acetonitrile, where fluorescence quenching is observed with an intracomplex quenching rate constant of 1.9 x 10 9 s - 1 . Photoinduced intracomplex electron transfer is invoked as a likely mechanism of the fluorescence quenching and triplet bleaching.