[Ni(P<sup>Ph</sup><sub>2</sub>N<sup>C6H4X</sup><sub>2</sub>)<sub>2</sub>]<sup>2+</sup>Complexes as Electrocatalysts for H<sub>2</sub>Production: Effect of Substituents, Acids, and Water on Catalytic Rates
作者:Uriah J. Kilgore、John A. S. Roberts、Douglas H. Pool、Aaron M. Appel、Michael P. Stewart、M. Rakowski DuBois、William G. Dougherty、W. Scott Kassel、R. Morris Bullock、Daniel L. DuBois
DOI:10.1021/ja109755f
日期:2011.4.20
as overpotentials are decreased. Catalytic studies using acids with a range of pK(a) values reveal that turnover frequencies do not correlate with substrate acid pK(a) values but are highly dependent on the acid structure, with this effect being related to substrate size. Addition of water is shown to dramatically increase catalytic rates for all catalysts. With [Ni(P(Ph)(2)N(C6H4CH2P(O)(OEt)2)(2))(2)](BF(4))(2)
一系列单核镍(II)双(二膦)配合物[Ni(P(Ph)(2)N(C6H4X)(2))(2)](BF(4))(2) (P(Ph)( 2)N(C6H4X)(2) = 1,5-di(para-X-phenyl)-3,7-diphenyl-1,5-diaza-3,7-diphosphacyclooctane;X = OMe, Me, CH(2 )P(O)(OEt)(2)、Br 和 CF(3)) 已被合成和表征。X 射线衍射研究表明 [Ni(P(Ph)(2)N(C6H4Me)(2))(2)](BF(4))(2) 和 [Ni(P(Ph)(2)N (C6H4OMe)(2))(2)](BF(4))(2) 是具有扭曲方形平面几何形状的四坐标。每个配合物的 Ni(II/I) 和 Ni(I/0) 氧化还原对在乙腈中是电化学可逆的,随着 X 给电子特性的增加,其阴极电位越来越高。这些配合物中的每一种都是在 Ni(II/I)