Characteristic Reactivties and Functions of Metal Complexes containing Hypodentate Ligands.

下齿配体是指与金属中心结合的供体原子少于最大可能数目的配体。本研究的目的是制备各种含这些配体的新型配合物，并研究它们的反应性和功能特性。我们特别关注发光配合物，因为利用不配位的配体来控制光物理性质是很有前途的。用三（2-吡啶基甲基）胺（tpa）和N，N，N‘，N’-四（2-吡啶基甲基）乙二胺（tpen）等多吡啶基配体得到的结果如下：(i)与这些配体的一系列平面Pt（II）和Pd（II）配合物均具有不配位的旋臂。自由旋臂和配位旋臂的交换顺序为Pt(II) < Pd（II）和tpa < tpen。（ii）制备了发光的[Re(CO)_3(tpa)]^+，它也有一个不与配位臂发生交换的非配位臂。（iii） tpa的V^<IV>O配合物具有完全配位的tpa（四齿），不同于具有三齿tpa的ReO-tpa配合物，但已分离出含有下齿配体的V^<IV>O配合物。以二膦配体Ph_2P(CH_2)_nPPh_2 （n = 1 ~ 5）为原料，制备了一系列含单齿二膦的发光六芳簇配合物。对于六苯基单元，我们也成功地引入了巨配体游离基吡啶卟啉。我们还使用了一种小的多齿配体，2.5-二巯基-1,3,4-噻二唑（McMTH）。所制备的配合物包括含有单齿McMT的配合物为[Pt(terpy) (McMT)]^+和[Ru(terpy)(bpy)(McMT)]^+。它们与另一个Pt（terpy）单元反应形成同核和异核配合物。此外，还得到了不同类型的Cu(I)和Ag(I)配合物。所有这些McMT复合物都是强发光的。

Hypodentate ligand is defined as a ligand in which fewer than the maximum possible number of donor atoms are bonded to metal centers. The purpose of the study is to prepare various new complexes containing such ligands and to investigate their reactivities and functional characteristics. In particular we have paid special attention to luminecent complexes as the control of photophysical properties by using uncoordinated ligand moieties are promising. The results obtained by using polypyridyl ligands such as tris(2-pyridylmethyl)amine (tpa) and N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (tpen) are as follows, (i) A series of planar Pt(II) and Pd(II) complexes with these ligands all have uncoordinated arms. The exchange of the free and coordinated arms have been found in the order Pt(II) < Pd(II) and tpa < tpen. (ii) Luminescent [Re(CO)_3(tpa)]^+ has been prepared which also has one uncoordinated arm that does not undergo exchange with the coordinated ones. (iii) V^<IV>O complexes of tpa has fully coordinated tpa (tetradentate), different from ReO-tpa complexes which have tridentate tpa, but with tpen V^<IV>O complex containing hypodentate ligand has been isolated. With the diphosphine ligands Ph_2P(CH_2)_nPPh_2 (n = 1 - 5), a series of luminescent hexarhenium cluster complexes containing monodentate diphosphines have been obtained. For the hexarhenium unit, we have also successfully introduced giant ligands free base pyridylporphyrines. We have also used a small polydentate ligand, 2.5-dimercapto-1,3,4-thiadiazole(McMTH). The complexes prepared include those containing a monodentate McMT are [Pt(terpy) (McMT)]^+ and [Ru(terpy)(bpy)(McMT)]^+. They react with another Pt(terpy)-unit to form homo and hetero dinuclear complexes. Furthermore various type of Cu(I) and Ag(I) complexes of McMT ligands have been obtained. All these McMT complexes are strongly luminescent.