Controlling proton movement: Electrocatalytic oxidation of hydrogen by a nickel(ii) complex containing proton relays in the second and outer coordination spheres

Parthapratim Das, Ming Hsun Ho, Molly O'Hagan, Wendy J. Shaw, R. Morris Bullock, Simone Raugei, Monte L. Helm

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

A nickel bis(diphosphine) complex containing proton relays in the second and outer coordination spheres, Ni(PCy2N (CH2)2OMe)2, (PCy2N (CH2)2OMe = 1,5-di(methoxyethyl)-3,7-dicyclohexyl-1,5-diaza-3,7- diphosphacyclooctane), is an electrocatalyst for hydrogen oxidation. The addition of hydrogen to the Ni(ii) complex results in rapid formation of three isomers of the doubly protonated Ni(0) complex, [Ni(PCy 2N(CH2)2OMe2H)2]2+. The three isomers show fast interconversion at 40 °C, unique to this complex in this class of catalysts. Under conditions of 1.0 atm H2 using H 2O as a base, catalytic oxidation proceeds at a turnover frequency of 5 s-1 and an overpotential of 720 mV, as determined from the potential at half of the catalytic current. Compared to the previously reported Ni(PCy2NBn)2 complex, the new complex operates at a faster rate and at a lower overpotential.

Original languageEnglish
Pages (from-to)2744-2754
Number of pages11
JournalDalton Transactions
Volume43
Issue number7
DOIs
Publication statusPublished - Feb 21 2014

ASJC Scopus subject areas

  • Inorganic Chemistry

Fingerprint Dive into the research topics of 'Controlling proton movement: Electrocatalytic oxidation of hydrogen by a nickel(ii) complex containing proton relays in the second and outer coordination spheres'. Together they form a unique fingerprint.

  • Cite this