Methylthiophenyl- and Methylthiobiphenyl-Substituted A<sub>2</sub>B Co<sup>III</sup>corroles: Modulating Electrocatalyzed Hydrogen Evolution Reactions on Surface-Modified Gold Electrodes
Zhiheng Qu, Yu Wang, Minzhi Li, Weihua Zhu, John Mack, Nthabeleng Molupe, Tebello Nyokong, Xü Liang
Abstract
Four A 2 B-type Co III corroles ( 2a–2d ) with electron-donating/withdrawing substituents at the A 2 meso -aryl substituents and a 4-(methylthio)phenyl ring at the B position have been synthesized and characterized, along with a series of meso -extended Co III corroles ( 4a – 4c ) with 4′-(methylthio)biphenyl moieties. The electronic structures and structure–property relationships of the dyes have been analyzed by comparing their redox and optical properties to trends predicted in density functional theory calculations. Au electrodes surface-modified with 2a – 2d and 4a – 4c are highly efficient catalysts for electrocatalyzed hydrogen evolution reactions, and the electrocatalytic properties can be readily modulated by fine-tuning the electronic structure of the Co III corrole and the distance between the “Au–S” bond and Co III center.