Syntheses, Photophysical Properties, and Reactivities of Novel Bichromophoric Pd Complexes Composed of Ru(II) Polypyridyl and Naphthyl Moiety
Syntheses, Photophysical Properties, and Reactivities of Novel Bichromophoric Pd Complexes Composed of Ru(II) Polypyridyl and Naphthyl Moiety
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由 Ru(II) 聚吡啶基和萘基部分组成的新型双发色 Pd 配合物的合成、光物理性质和反应活性
DOI：
10.1039/c3dt50266j
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发表时间：
2013
影响因子：
4
通讯作者：
M. Akita
中科院分区：
文献类型：
--
作者：
K. Murata;M. Araki;A. Inagaki;M. Akita
合成了一系列以2，2‘-联吡啶(Bpy)和2，2’-联嘧啶(Bpm)为桥联基发色团的新型双发色Ru(II)配合物。与Pd-烷基单元的络合反应形成了双色Ru-Pd催化剂。研究了新合成的化合物的光化学性质和电化学性质。结果表明，紫外光吸收的光能被有效地转移到Ru(II)中心，这与可见光激发观察到的金属与配体之间的电荷转移发光是一致的。含有直接连接到bpy配体上的萘基的配合物的发光寿命延长到约1000 ns。当含有延长寿命的双色单元的Pd络合物作为催化剂时，在可见光或紫外光照射下观察到了苯乙烯的聚合，这与其他催化剂的二聚反应形成了鲜明的对比。这些结果表明，形成了具有较长激发态寿命的激发态，这促进了插入步骤而不是竞争的β-H消除步骤。
A series of novel bichromophoric Ru(II) complexes bearing a naphthyl chromophore linked with 2,2′-bipyridyl (bpy) and 2,2′-bipyrimidine (bpm) ligands were synthesized. Complexation with a Pd-alkyl unit led to the formation of bichromophoric Ru–Pd catalysts. The photochemical and electrochemical properties of the newly synthesized compounds were studied. It has been shown that the UV-light energy absorbed at the pendant naphthyl moiety is effectively transferred to the Ru(II) center; this is supported by the observation of metal-to-ligand charge-transfer luminescence through excitation of the naphthyl unit, which is identical to the luminescence observed through visible light excitation. The luminescence lifetime of the complex bearing a naphthyl moiety directly connected to the bpy ligands was lengthened to ca. 1000 ns. When a Pd complex containing the bichromophoric unit with an extended lifetime was used as a catalyst, styrene polymerization under visible or UV light irradiation was observed, in clear contrast to dimerization using other catalysts. These results indicate the formation of an excited-state with a prolonged excited-state lifetime, which promotes an insertion step in preference to the competing β-H elimination step.