Control of photochemical, photophysical, electrochemical, and photocatalytic properties of rhenium(I) complexes using intramolecular weak interactions between ligands.
Control of photochemical, photophysical, electrochemical, and photocatalytic properties of rhenium(I) complexes using intramolecular weak interactions between ligands.
复制标题
DOI：
10.1021/ja053814u
复制
发表时间：
2005-10
影响因子：
15
通讯作者：
H. Tsubaki;A. Sekine;Y. Ohashi;K. Koike;Hiroyuki Takeda;O. Ishitani
中科院分区：
文献类型：
--
作者：
H. Tsubaki;A. Sekine;Y. Ohashi;K. Koike;Hiroyuki Takeda;O. Ishitani
配体间的分子内相互作用已被成功地用作控制一系列顺，反-[Re（dmb）（CO）（2）（PR（3））（PR '（3））]（+）型配合物（dmb = 4，4'-二甲基-2，2 '-联吡啶）基态、激发态和单电子还原态的各种性质的新工具。对于具有两个三芳基膦配体P（p-XPh）（3）的dmb配合物，dmb配体被具有CH（芳基）-pi（吡啶）-pi（芳基）相互作用的四个芳基环夹在中间。另一方面，具有一个三芳基膦配体和一个三烷基亚磷酸酯配体的配合物P（OR）（3）在DMB配体中的每个吡啶环和P（p-XPh）（3）中的芳基之间具有pi-pi和CH-pi相互作用。这两个系列的配合物的各种性能进行了比较，与那些配合物有两个三烷基亚磷酸酯配体，不通过空间与DMB配体相互作用。配合物的性质主要受分子内相互作用的影响：（1）对π-π和（1）MLCT激发态的紫外/维斯吸收均发生红移，但（2）（3）MLCT激发态的发射发生蓝移，（3）MLCT激发态的寿命延长3倍;（4）π-π和CH-π相互作用使基态还原电位正移110 mV，CH-π-π相互作用使基态还原电位正移180-200 mV。(5)在激发态，分子内相互作用也增强了配合物的氧化能力。(6)在相应的单电子还原物种cis，trans-Re（dmb（-.）（CO）（2）（PR（3））（PR '（3））]，分子内相互作用得以维持，并强烈影响其紫外/维斯光谱。(7)光催化CO（2）还原仅通过CH-π-π相互作用而显著增强。
Intramolecular interactions between ligands have been successfully applied as a novel tool for controlling various properties of a series of cis,trans-[Re(dmb)(CO)(2)(PR(3))(PR'(3))](+)-type complexes (dmb = 4,4'-dimethyl-2,2'-bipyridine), in the ground state and in the excited state and in the one-electron reduced form. For rhenium complexes with two triarylphosphine ligands, P(p-XPh)(3), the dmb ligand was sandwiched by four aryl rings having CH(aryl)-pi(pyridine)-pi(aryl) interactions. On the other hand, complexes with one triarylphosphine ligand and one trialkylphosphite ligand, P(OR)(3), had pi-pi and CH-pi interactions between each pyridine ring in the dmb ligand and the aryl group in the P(p-XPh)(3). Various properties of these two series of rhenium complexes were compared with those of complexes having two trialkylphosphite ligands, which do not interact through space with the dmb ligand. Properties of the complexes associated mainly with the dmb ligand are strongly affected by the intramolecular interactions: (1) UV/vis absorptions to the pi-pi and (1)MLCT excited states were both red-shifted, but (2) emission from the (3)MLCT excited state was blue-shifted; (3) the lifetime of the (3)MLCT excited state was prolonged up to 3-fold; (4) the reduction potential in the ground state was positively shifted by 110 mV with pi-pi and CH-pi interactions and by 180-200 mV with the CH-pi-pi interactions. (5) In the excited states, the oxidation power of the complex was also enhanced by the intramolecular interactions. (6) In the corresponding one-electron-reduced species cis,trans-[Re(dmb(-.)(CO)(2)(PR(3))(PR'(3))], the intramolecular interactions are maintained and strongly affected their UV/vis spectra. (7) Photocatalysis for CO(2) reduction was significantly enhanced only by the CH-pi-pi interaction.