Metal assembly in novel dendrimers with porphyrin cores
Metal assembly in novel dendrimers with porphyrin cores
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DOI：
10.1021/ja0285060
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发表时间：
2003-01-15
影响因子：
15
通讯作者：
Yamamoto, K
中科院分区：
文献类型：
--
作者：
Imaoka, T;Horiguchi, H;Yamamoto, K
以meso-四（4-氨基苯基）卟啉和DPA树枝状分子为原料，经TiCl 4脱水反应合成了一系列以卟啉（PnH 2）为核的苯偶氮甲川（DPA）树枝状分子。树枝状钴卟啉的二氯甲烷/乙腈溶液中加入SnCl 2后，光谱呈阶梯状变化。通过使用紫外-维斯光谱监测P4 CoIIICl的络合作用，直到加入等摩尔量的SnCl 2，在加入SnCl 2的过程中观察到等吸光点位置的四个变化。滴定结果表明，四个不同的配合物相继形成后，SnCl 2加成和络合的进行，而不是随机的，但逐步的方式从核心亚胺的末端亚胺的P4 CoIIICl。电化学研究表明，含Tb离子的树枝状聚合物在高电位下作为多电子介体参与了CO2的还原反应.
A series of phenylazozmethine (DPA) dendrimers with a porphyrin core (PnH2) were synthesized by dehydration using TiCl4frommeso-tetrakis(4-aminophenyl)porphyrin and the DPA dendrons. The addition of SnCl2to a dichloromethane/acetonitrile solution of dendritic cobalt porphyrin resulted in a stepwise spectral change. By using UV−vis spectroscopy to monitor the complexation of the P4CoIIICl until an equimolar amount of SnCl2has been added, four changes in the position of the isosbestic point were observed during the addition of SnCl2. Titration results suggest that four different complexes are successively formed upon the SnCl2addition and that the complexation proceeds in, not a random, but a stepwise fashion from the core imines to the terminal imines of P4CoIIICl. The electrochemical study reveals that their dendrimers with Tb ion act as a multielectron mediator in CO2reduction at high applied potential on the electrode.