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Controlling Proton Delivery through Catalyst Structural Dynamics
Author(s) -
Cardenas Allan Jay P.,
Ginovska Bojana,
Kumar Neeraj,
Hou Jianbo,
Raugei Simone,
Helm Monte L.,
Appel Aaron M.,
Bullock R. Morris,
O'Hagan Molly
Publication year - 2016
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201607460
Subject(s) - catalysis , protonation , chemistry , turnover number , molecular dynamics , overpotential , active site , ligand (biochemistry) , proton , protein dynamics , computational chemistry , biochemistry , physics , organic chemistry , ion , receptor , electrode , quantum mechanics , electrochemistry
The fastest synthetic molecular catalysts for H 2 production and oxidation emulate components of the active site of hydrogenases. The critical role of controlled structural dynamics is recognized for many enzymes, including hydrogenases, but is largely neglected in designing synthetic catalysts. Our results demonstrate the impact of controlling structural dynamics on H 2 production rates for [Ni(P Ph 2 N C6H4R 2 ) 2 ] 2+ catalysts (R= n ‐hexyl, n ‐decyl, n ‐tetradecyl, n ‐octadecyl, phenyl, or cyclohexyl). The turnover frequencies correlate inversely with the rates of chair–boat ring inversion of the ligand, since this dynamic process governs protonation at either catalytically productive or non‐productive sites. These results demonstrate that the dynamic processes involved in proton delivery can be controlled through modification of the outer coordination sphere, in a manner similar to the role of the protein architecture in many enzymes. As a design parameter, controlling structural dynamics can increase H 2 production rates by three orders of magnitude with a minimal increase in overpotential.