A series of cyclometalated dinuclear platinum(II) complexes bridged by pyridine-2-thiolate (pyt) ions, [Pt2(L)2(pyt)2] (HL = 2-(p-tolyl)pyridine (Hptpy), 2-(2-thienyl)pyridine (Hthpy), or benzo[h]quinoline (Hbzqn)), as well as their two-electron-oxidized dinuclear platinum(III) complexes, [Pt2Cl2(L)2(pyt)2], have been synthesized and characterized. The structures and luminescence properties have been investigated by comparing them with those of the corresponding 2-phenylpyridinato (ppy) complex. All divalent complexes have similar dinuclear frameworks, with short Pt···Pt distances (ca. 2.85 Å), and exhibit similar intense luminescence from the triplet metal–metal-to-ligand charge-transfer (3MMLCT) state in glassy solutions. However, they provide different luminescence features reflecting their dynamic behaviors in fluid solutions and their intermolecular interactions in the solid state. [Pt2(bzqn)2(pyt)2] containing fused aromatic rings exhibits the most sensitive features to the environment, i.e., it shows the most red-shifted luminescence spectrum in the solid state due to the intermolecular π–π interaction. However, in fluid solution, it provides very weak luminescence based on a rapid nonradiative deactivation mainly caused by the fluctuation of the intramolecular π–π repulsion between the ligands. [Pt2(ptpy)2(pyt)2], on the other hand, is the most stable luminophore, which always exhibits intense luminescence with an almost constant emission maximum independent of its temperature and state.
一系列由
吡啶-2-
硫醇盐 (pyt) 离子桥接的环
金属化双核
铂 (II) 配合物,[Pt2(L)2(pyt)2] (HL = 2-(
对甲苯基)
吡啶 (Hptpy), 2- (2-
噻吩基)
吡啶 (Hthpy) 或苯并[h]
喹啉 (Hbzqn)) 及其双电子氧化双核
铂 (III) 配合物 [Pt2Cl2(L)2(pyt)2] 具有进行了合成和表征。通过与相应的
2-苯基吡啶 (ppy) 配合物进行比较,研究了其结构和发光性质。所有二价配合物都具有相似的双核骨架,具有短的 Pt·Pt 距离(约 2.85 Å),并且在
玻璃溶液中的三线态
金属-
金属-
配体电荷转移 (3MMLCT) 状态下表现出相似的强发光。然而,它们提供不同的发光特征,反映它们在流体溶液中的动态行为以及它们在固态中的分子间相互作用。含有稠合芳环的[Pt2(bzqn)2(pyt)2]表现出对环境最敏感的特征,即由于分子间π-π相互作用,它在固态下显示出最红移的发光光谱。然而,在流体溶液中,它基于快速非辐射失活而提供非常弱的发光,这主要是由
配体之间的分子内 π-π 排斥力的波动引起的。另一方面,[Pt2(ptpy)2(pyt)2] 是最稳定的发光体,它总是表现出强烈的发光,并且无论其温度和状态如何,其发射最大值几乎恒定。