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Synthesis and Molecular-assembling of Metal Polynuclear Complexes as a Switching Molecular Devices by Proton Transfer

通过质子转移合成和分子组装金属多核配合物作为开关分子器件

基本信息

批准号：
04453045
负责人：
HAGA Masa-aki
金额：
$ 5.06万
依托单位：
Mie University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1993
项目状态：
已结题

项目摘要

In the Ru complexes containing the proton dissociable LH, the thermodynamic relations between electron transfer, proton transfer and photoexcitation can be summarized by a three-dimensional cubic scheme(Fig.1). In this scheme, the thermodynamic quantities such as pK_a and redox potential E_<1/2> are correlated each other. This thermodynamic scheme inspires us to design the supramolecular complexes which can possess a proton-induced switching activity. The proton dissociation in Ru complexes leads to the changes of redox potentials and donor poperty of the ligand, which induces the switching of redox and photochemical properties in the complexes. To elucidate this phenomenon, new dinuclear Ru complexes containing proton dissociable benzimidazole derivatives have been prepared. As a bridging ligand, several new ligands were introduced ; i.e., 2,2'-bis(2-benzimidazolyl)-4,4'-bipyridine(bbbpyH_2) and 2,2'-bis(2-pyridyl)-bibenzimidazole(bpbimH_2). A series of mono-, di-, tri-and tetranuclear Ru complexes bridged by these benzimidazole derivatives have been synthezized. Proton transfer in these complexes can functionas an external perturbation for (1) the change of the metal-metal interaction through bnridging ligand ; (2) the change of the localized position for the excited electron ; (3) the change of the pathway for the electron transfer ; (4) the change of the multielectron transfer pocesses ; for example, the change from the two-electron process to two one-electron processes. The complexes exhibit different switching modes on the redox behaviors, emission, or metal-metal interaction.

在含有质子可解离LH的Ru配合物中，电子转移、质子转移和光激发之间的热力学关系可以用三维立方格式来概括（图1）。在该方案中，热力学量pK_a和氧化还原电位E_<1/2>相互关联。这一热力学方案启发我们设计具有质子诱导开关活性的超分子配合物。钌配合物中的质子解离引起配体的氧化还原电位和给体性质的改变，从而引起配合物中氧化还原和光化学性质的转换。为了阐明这一现象，制备了含有质子可解离苯并咪唑衍生物的新型双核钌配合物。作为桥接配体，引入了几种新的配体；即2,2'-双（2-苯并咪唑）-4,4'-联吡啶（bbbpyH_2）和2,2'-双（2-吡啶基）-联并咪唑（bpbimH_2）。合成了一系列由这些苯并咪唑衍生物桥接的单核、二核、三核和四核钌配合物。这些配合物中的质子转移可以作为外部扰动：(1)通过桥接配体改变金属-金属相互作用；(2)受激电子局域位置的变化；(3)电子转移途径的改变；(4)多电子转移过程的变化；例如，从两个电子过程到两个单电子过程的变化。这些配合物在氧化还原行为、发射或金属-金属相互作用方面表现出不同的开关模式。