Effectual electrocatalytic proton and water reduction by CuII terpyridine scaffolds

Electrocatalytic hydrogen evolution by a dinuclear copper complex and mechanistic elucidation through DFT studies

A novel dinuclear copper complex, [CuII2(L1)2] (L1 = 2-{[2-(8-hydroxyquinolin-2-yl)-1H-benzimidazol-1-yl]methyl}quinolin-8-ol) was synthesised and characterised through various spectroscopic techniques. This dinuclear complex (as an electrocatalyst) was employed to examine the catalytic ability towards an electrochemical hydrogen evolution reaction (HER). Redox studies in 95/5 (v/v) DMF/H2O with the addition of 30-equivalent AcOH (acid source) led to higher catalytic activities for the HER. The evolved H2, as the resultant product, was detected and confirmed from gas chromatography to afford a faradaic efficiency of 93% at an applied potential of -1.9 V vs. SCE. Based upon measurements of open-circuit potential and electrocatalytic responses, the mechanistic route for the reduction process using [CuII2(L1)2] was elucidated. Density functional theory studies reveal that through a concerted proton-coupled electron transfer (PCET) path, the HER proceeded via the formation of a Cu-H bond with a low activation energy for the dehydrogenation reaction.

Electrocatalytic proton reduction by dinuclear cobalt complexes in a nonaqueous electrolyte

Two dinuclear CoII complexes 1 and 2 have been synthesized and characterized using various spectroscopic methods. Both the complexes were employed for H+ reduction in organic media. Faradaic efficiency of 82–90% was obtained for the H2 evolution.

Syntheses, crystal structures and supramolecular assemblies of two Cu(ii) complexes based on a new heterocyclic ligand: insights into C–H⋯Cl and π⋯π interactions

A new heterocyclic ligand, N3L [4-(1-methylimidazole)-2,6-di(pyrazinyl)pyridine] and two Cu(ii) complexes have been synthesized and characterized by several spectroscopic and DFT methods.