title: Why is a proton transformed into a hydride by [NiFe] hydrogenases? An intrinsic reactivity analysis based on conceptual DFT.
abstract: The hydrogen evolution reaction (HER) catalysed by [NiFe] hydrogenases entails a series of chemical events involving great mechanistic interest. In an attempt to understand and delve into the question about 'Why does nature work in that way?', an in-depth intrinsic reactivity analysis based on conceptual DFT has been carried out focusing on the so-called to step, i.e. our work tries to answer how and why the proton attached to the reactive sulphur atom from one of the exo-cyclic cysteine residues is transformed into a bridging hydride to be shared between the Ni/Fe metals in the active site of [NiFe] hydrogenases, which involves not only H migration, but also a change of the charge state on Ni from Ni(i) to Ni(iii). Our DFT results suggest that the transformation is motivated by spontaneous rearrangements of the electron density, and stabilisation comes from the decrease of both electronic activity and electrophilicity index from Ni.
authors.affiliation: School of Chemistry, Faculty of Science, Monash University, Clayton, VIC 3800, Australia. Douglas.MacFarlane@monash.edu Chenghua.Sun@monash.edu.
authors.forename: Siyao
authors.initials: S
authors.lastname: Qiu
authors.affiliation: School of Chemistry, Faculty of Science, Monash University, Clayton, VIC 3800, Australia. Douglas.MacFarlane@monash.edu Chenghua.Sun@monash.edu and ARC Centre of Excellence for Electromaterials Science (ACES), School of Chemistry, Faculty of Science, Monash University, Clayton, VIC 3800, Australia.
authors.forename: Luis Miguel
authors.initials: LM
authors.lastname: Azofra
authors.affiliation: School of Chemistry, Faculty of Science, Monash University, Clayton, VIC 3800, Australia. Douglas.MacFarlane@monash.edu Chenghua.Sun@monash.edu and ARC Centre of Excellence for Electromaterials Science (ACES), School of Chemistry, Faculty of Science, Monash University, Clayton, VIC 3800, Australia.
authors.forename: Douglas R
authors.initials: DR
authors.lastname: MacFarlane
authors.affiliation: School of Chemistry, Faculty of Science, Monash University, Clayton, VIC 3800, Australia. Douglas.MacFarlane@monash.edu Chenghua.Sun@monash.edu and ARC Centre of Excellence for Electromaterials Science (ACES), School of Chemistry, Faculty of Science, Monash University, Clayton, VIC 3800, Australia.
authors.forename: Chenghua
authors.initials: C
authors.lastname: Sun