Tuning the Electronic and Molecular Structures of Bioinspired Heterodinuclear NiFe Catalyst for Enhanced Catalytic H Evolution.

With the aim of enhancing the HER activity of the previously described bioinspired [NiFe]-hydrogenase complex [LNiFeCp-(CO)] (, with L = 2,2'-(2,2'-bipyridine-6,6'-diyl)-bis-(1,1'-diphenylethanethiolate) and Cp = cyclopentadienyl), the electronic structure of the L site has been fine-tuned. In , the bipyridine (Bpy) unit was substituted with methoxy electron-donating groups, while in , the Bpy unit was replaced with the 1,10-phenanthroline backbone. These complexes were fully characterized, and their HER activity was investigated.

Non-Heme Tri-Iron(II) Complex as a Precursor for Dioxygen Activation and Oxygen Reduction Reaction Catalysis.

Nonheme iron catalysts are attractive for bioinspired aerobic oxidations and oxygenations, as well as for the oxygen reduction reaction (ORR), although their potential in ORR remains largely underexploited. This study presents a rare example of such a system, displaying O activation activity and ORR catalytic selectivity toward HO generation. The triiron(II) complex [FeL](BF), where L is a thiolate-containing N3S donor bis(2-pyridylmethyl)amine derivative, was fully characterized in the solid state and in MeCN solution, where it dissociates into the mononuclear solvent adduct [FeL(MeCN)].

A Pyrene-Triazacyclononane Anchor Affords High Operational Stability for CO RR by a CNT-Supported Histidine-Tagged CODH.

An original 1-acetato-4-(1-pyrenyl)-1,4,7-triazacyclononane (AcPyTACN) was synthesized for the immobilization of a His-tagged recombinant CODH from Rhodospirillum rubrum (RrCODH) on carbon-nanotube electrodes. The strong binding of the enzyme at the Ni-AcPyTACN complex affords a high current density of 4.9 mA cm towards electroenzymatic CO reduction and a high stability of more than 6×10  TON when integrated on a gas-diffusion bioelectrode.