Synthesis and characterization of hemicage 8-hydroxyquinoline chelates with enhanced electrochemical and photophysical properties

被引：36

作者：

Wang, Jingjing ^{[1
]}

Oyler, Karl D. ^{[1
]}

Bernhard, Stefan ^{[1
]}

机构：

[1] Princeton Univ, Dept Chem, Princeton, NJ 08544 USA

来源：

INORGANIC CHEMISTRY | 2007年 / 46卷 / 14期

基金：

美国国家科学基金会;

关键词：

D O I：

10.1021/ic700542t

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

A new hexadentate, tripodal 8-hydroxyquinoline ligand (QH(3)) and its trivalent metal chelates (MQ, M = Al3+, Ga3+, In3+) with hemicage structures have been prepared and the electrochemical and photophysical properties systematically studied. The hemicage structure of the metal complexes was characterized by H-1 NMR, indicating a pure facial geometry, in contrast to their uncaged cousins with 8-hydroxyquinoline (Mq(3)) and 3-methyl-8-hydroxyquinoline (M(3Meq)(3)), which all exist only as the meridional form in fluid solutions at room temperature. The photoluminescence quantum efficiency for the three hemicage complexes is 1.48, 1.79, and 1.26 times higher for AlQ, GaQ, and InQ, respectively, than their corresponding 3-methyl-8-hydroxyquinoline complexes, likely due to the rigidity of the ligand system, which can efficiently decrease the nonradiative decay of the excited states. The improved electrochemical stability of the hemicage complexes has been demonstrated by cyclic voltammetry, showing an increasingly reversible behavior from InQ to GaQ to AlQ (E-red = -2.15, -2.17, and -2.22 V vs Fc/Fc(+) in DMSO). We infer that the degree of reversibility and redox potential result from the metal-ligand bond strength, which is largest in the case of aluminum.

引用

页码：5700 / 5706

页数：7

共 63 条

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