Improving Molecular Iron Ammonia Oxidation Electrocatalysts via Substituent Effects That Modulate Standard Potential and Stability.

Molecular ammonia oxidation (AO) catalysis is a rapidly evolving research area. Among the catalysts studied, featuring metals including ruthenium, iron, manganese, nickel, and copper, polypyridyl iron complexes are attractive owing to fast catalytic rates and significant turnover numbers (TON). Building upon our previous work on AO using [(TPA)Fe(MeCN)] and [(BPM)Fe(MeCN)], this study investigates factors that impact rate and TON within and across catalyst series based on polypyridyl ligand frameworks.

Mechanism of a Luminescent Dicopper System That Facilitates Electrophotochemical Coupling of Benzyl Chlorides via a Strongly Reducing Excited State.

Photochemical radical generation has become a modern staple in chemical synthesis and methodology. Herein, we detail the photochemistry of a highly reducing, highly luminescent dicopper system [Cu] (* ≈ -2.7 V vs SCE; ≈ 10 s) within the context of a model reaction: single-electron reduction of benzyl chlorides.

Enhanced Ammonia Oxidation Catalysis by a Low-Spin Iron Complex Featuring Coordination Sites.

The goal of using ammonia as a solar fuel motivates the development of selective ammonia oxidation (AO) catalysts for fuel cell applications. Herein, we describe Fe-mediated AO electrocatalysis with [(bpyPyMe)Fe(MeCN)], exhibiting the highest turnover number (TON) reported to date for a molecular system. To improve on our recent report of a related iron AO electrocatalyst, [(TPA)Fe(MeCN)] (TON of 16), the present [(bpyPyMe)Fe(MeCN)] system (TON of 149) features a stronger-field, more rigid auxiliary ligand that maintains -labile sites and a dominant low-spin population at the Fe(II) state.