Structural Chemical Approach to Molecular Recognition Using Luminescent Metal Complexes

1.(联吡吩嗪)铂(II)配合物的二维堆积新的含联吡啶[3，2-a：2‘，3’-c]吩嗪(Dppz)的铂(II)配合物在晶体中形成了具有铂-铂相互作用和配体pi-pi相互作用的二维堆积结构。不同分子间相互作用控制的二亚胺-铂(II)配合物的晶体结构和发射性质。研究了直链铂(II)配合物[铂(CN)_2(Bpy)](bpy=2，2‘-联吡啶)和[Pt(CN)_2(i-biq)](i-biq=3，3’-联喹啉)的发射光谱和晶体结构与温度的关系。对于[Pt(CN)_2(Bpy)]，在300K-15K温度范围内，3MLCT发射能量与铂-铂距离之间有很好的相关性。而对于[铂(CN)_2(i-biq)]，随着温度的降低，收缩发生在叠层之间，而不是铂-铂间距，这是由于…的增加堆叠中复杂单元的倾角更大。随着温度的降低，除了_3MLCT发射外，还出现了_3PIPI*(i-biq)发射。这些结果表明，pi-pi和铂-铂相互作用在控制晶体结构和发射态方面起着重要作用。对于这些配合物，在77K的稀玻璃溶液中发现了浓度依赖的组装：除了在波长为530 nm处有结构的_3PIPI*发射带外，在600-800 nm范围内还出现了一个宽带带，且相对强度随着浓度的增加而增加。发射行为表明在极稀溶液中形成了具有铂-铂相互作用的二聚体(或低聚物)物种。(二亚胺)(乙二胺)铂(II)对游离邻菲罗啉的选择性吸收当非平面乙二胺(EN)作为另一种配体时，空间位阻阻止了铂-铂相互作用的堆积。我们发现这类配合物[Pt(En)(L)]^2+(L=bpy，phen[1，10-邻菲咯啉])与游离邻菲咯啉形成1：1的完整堆积。Pi-pi相互作用和氢键稳定了堆栈。有趣的是，在许多芳香族化合物中，phen的包含是选择性的，这对分子识别是非常有用的。较少

1. Two-Dimensional Stacking of (Dipyridophenazine)platinum(II) Complexes. Novel platinum(II) complexes containing dipyrido[3,2-a : 2', 3'-c]phenazine (dppz) have been found to form two-dimensional stackingstructures which have constructed with both platinum-platinum and ligand pi-pi interactions in the crystals.2. Crystal Structures and Emission Properties of Diimine-platinum(II) Complexes Controlled by Various Intermolecular Interactions. Temperature dependence of emission spectra and crystal structures has been investigated for the linear-chain platinum(II) complexes, red forms of [Pt(CN)_2(bpy)] (bpy = 2,2'-bipyridine) and [Pt(CN)_2(i-biq)] (i-biq = 3,3'-biisoquinoline). For [Pt(CN)_2(bpy], a good correlation between the _3MLCT emission energy and the Pt-Pt distance has been obtained in the temperature range of 300-15 K.For [Pt(CN)_2(i-biq)], however, the shrinkage occurs between the stacks instead of the Pt-Pt spacing with decreasing temperature, which is due to an increase in the … More inclination angle of the complex units in the stack. With decreasing temperature, the _3pipi*(i-biq) emission appears, in addition to the _3MLCT emission. These results indicate that the pi-pi and Pt-Pt interactions competitively play important roles in controlling the crystal structure and the emission state, For these complexes, concentration-dependent assemblage was found in a dilute glassy solution at 77 K : In addition to a structured _3pipi* emission band at lambda_<max> = 530 nm, a broad band appeared at a range of 600-800 nm and the relative intensity was increased with concentration. The emission behavior suggests the formation of dimeric (or oligomeric) species with Pt-Pt interaction in extremely dilute solution.3. Selective Uptake of Free Phenanthroline by (Diimine)(ethylenediamine)platinum(II). When non-planar ethylenediamine (en) is used as another ligand, the steric hindrance prevents the complexes from stacking with Pt-Pt interactions. We have found that this type of complexes, [Pt(en)(L)]^2+(L = bpy, phen [1,10-phenanthroline]), form a 1 : 1 integrated stack with free phenanthrolines. The pi-pi interactions and the hydrogen bonds stabilize the stack. Interestingly, the inclusion of phen in the integrated stack is selective among many aromatic compounds, which is very informative on the molecular recognition. Less