Incorporating Peptides in the Outer-Coordination Sphere of Bioinspired Electrocatalysts for Hydrogen Production
Incorporating Peptides in the Outer-Coordination Sphere of Bioinspired Electrocatalysts for Hydrogen Production
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DOI：
10.1021/ic1025872
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发表时间：
2011-05-02
影响因子：
4.6
通讯作者：
Shaw, Wendy J.
中科院分区：
文献类型：
--
作者：
Jain, Avijita;Lense, Sheri;Shaw, Wendy J.
合成了四个新的1，5-二氮杂-3，7-二磷杂环辛烷配体，并将其用于合成[Ni（p（2）（ph）N（2）（R））（2）]（2+）配合物，其中R为单或二肽。这些复合物代表了这类复合物的外配位领域的发展的第一步，可以模仿氢化酶的活性位点的外配位领域。重要的是，这些配合物保留了母体[Ni（（P2 N2 Ph）-N-Ph）（2）]（2+）配合物在乙腈溶液中的电催化活性，在对氰基苯胺三氟甲磺酸盐存在下，产氢的转换频率为14至25 s（-1），在质子化二甲基甲酰胺存在下，为135至1000 s（-1），具有适度低的过电位，添加少量水导致速率增加2-7倍。与母体复合物不同，这些复合物在溶液中表现出动态结构转变。这些结果建立了一个结构单元，从该结构单元可以添加更大的肽支架，以允许[Ni（p（2）（R）N（2）（R '））（2）]（2+）分子催化核心开始模拟酶的多功能外配位层。
Four new cyclic 1,5-diaza-3,7-diphosphacyclooctane ligands have been prepared and used to synthesize [Ni(p(2)(ph)N(2)(R))(2)](2+) complexes in which R is a mono- or dipeptide. These complexes represent a first step in the development of an outer-coordination sphere for this class of complexes that can mimic the outer-coordination sphere of the active sites of hydrogenase enzymes. Importantly, these complexes retain the electrocatalytic activity of the parent [Ni((P2N2Ph)-N-Ph)(2)](2+) complex in an acetonitrile solution with turnover frequencies for hydrogen production ranging from 14 to 25 s(-1) in the presence of p-cyanoaniliniurn trifluoromethanesulfonate and from 135 to 1000 s(-1) in the presence of protonated dimethylformamide, with moderately low overpotentials, similar to 0.3 V. The addition of small amounts of water results in rate increases of 2-7 times. Unlike the parent complex, these complexes demonstrate dynamic structural transformations in solution. These results establish a building block from which larger peptide scaffolding can be added to allow the [Ni(p(2)(R)N(2)(R'))(2)](2+) molecular catalytic core to begin to mimic the multifunctional outer-coordination sphere of enzymes.