A Heteropolynuclear Pt－Ag System Having Cycloplatinated Rollover Bipyridyl Units
A Heteropolynuclear Pt－Ag System Having Cycloplatinated Rollover Bipyridyl Units
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具有环铂翻转联吡啶单元的杂多核Pt－Ag体系
DOI：
10.1021/acs.inorgchem.0c02843
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发表时间：
2021
影响因子：
4.6
通讯作者：
Umakoshi Keisuke
中科院分区：
文献类型：
--
作者：
Horiuchi Shinnosuke;Tanaka Seiya;Moon Sangjoon;Sakuda Eri;Ito Akitaka;Arikawa Yasuhiro;Umakoshi Keisuke
报道了含环化、翻转联吡啶配体（bpy*）和桥联吡唑配体的杂多核铂银配合物的合成和物理性质。由具有翻转bpy* 配体[Pt（bpy*）（dmso）Cl]的Pt（II）络合物前体与3，5-二甲基吡唑（Me 2 pzH）通过两步反应合成Pt 2Ag 2络合物，随后用Ag（I）离子取代Me 2 pzH部分中的NH质子。Pt_2Ag_2配合物在溶液中以U形和Z形异构体的混合物形式存在，其结构通过单晶X射线结构分析得到了明确的确定。单晶的NMR研究表明Pt 2Ag 2配合物在溶液中的快速异构化，虽然Pt 2Ag 2结构有效地支持了多种金属-金属相互作用。此外，Pt 2Ag 2骨架在U-Z异构化过程中可以捕获Ag（I）离子，形成Pt → Ag配价键，形成Pt 2Ag 3核. Pt 2Ag 3配合物在配位溶剂存在下通过结晶过程进一步聚集形成二聚体结构。Pt → Ag配价键的形成显著地改变了Pt 2Ag 2配合物的发射能量，而Pt 2Ag 2配合物的U-和Z-异构体的发射光谱几乎一致，它们的发射性质非常相似。密度泛函理论（DFT）和含时DFT（TD-DFT）计算揭示了Ag（I）离子对含翻转bpy* 配体的杂多核Pt-Ag配合物的电子物理性质的影响.
The synthesis and photophysical properties of the heteropolynuclear Pt–Ag complex having cyclometalated rollover bipyridine ligands (bpy*) and bridging pyrazolato ligands are reported. The Pt2Ag2complex was synthesized by two step reactions from a Pt(II) complex precursor having the rollover bpy* ligand, [Pt(bpy*)(dmso)Cl], with 3,5-dimethylpyrazole (Me2pzH) and a subsequent replacement of NH protons in the Me2pzH moieties with the Ag(I) ion. The Pt2Ag2complex exists as a mixture of U- and Z-shaped isomers in solution, whose structures were clearly determined by single-crystal X-ray structural analyses. NMR studies using the single crystals revealed rapid isomerization of the Pt2Ag2complexes in solution, although the Pt2Ag2structures were supported effectively by the multiple metal–metal interactions. Furthermore, the Pt2Ag2framework can capture a Ag(I) ion during the U–Z isomerization to afford a Pt2Ag3core with the formation of Pt → Ag dative bonds. The Pt2Ag3complex showed further aggregation to form a dimer structure in the presence of coordinating solvent via the crystallization process. The formation of Pt → Ag dative bonds significantly changes the emission energy from the Pt2Ag2complex, while the emission spectra of U- and Z-isomers of Pt2Ag2complex almost coincide with each other and their emissive properties are very similar. The density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations revealed the effects of additional Ag(I) ion on the photophysical properties of the heteropolynuclear Pt–Ag complexes bearing the rollover bpy* ligands.