We have designed two new supramolecular assemblies based on Co(ii)-templated coordination of Ru(bpy)3(2+) (bpy = 2,2'-bipyridyl) analogues as photosensitizers and electron donors to a cobaloxime macrocycle, which are of interest as proton reduction catalysts. The self-assembled photocatalyst precursors were structurally characterized by Co K-edge X-ray absorption spectroscopy and solution-phase...

The title compound, [Co(C(14)H(14)Cl)(C(4)H(6)N(2)O(2))(2)(C(5)H(5)N)], is a model compound for the more complex cobalamines like vitamins B(12). The Co(III) atom is coordinated by a (4'-chloro-methyl-[1,1'-biphen-yl]-4-yl)methyl group, an N-bonded pyridine and two N,N'-bidentate dimethyl-glyoximate ligands in a distorted octa-hedral geometry. The glyoximate ligands exhibit intra-molecular O-H⋯...

A new cobaloxime was synthesized by the reaction of cobalt chloride and diphenylglyoxime in methanol, followed by the addition of 4′-(4-pyridyl)-2,2′:6′,2′′-terpyridine, pytpy. This complex was characterized by UV–Vis spectroscopy, 1H-NMR spectroscopy, cyclic voltammetry, and single-crystal X-ray diffraction analysis. In cyclic voltammetry experiments an irreversible reduction wave assigned to ...

Natural photosynthesis uses sunlight to drive the conversion of energy-poor molecules (H(2)O, CO(2)) to energy-rich ones (O(2), (CH(2)O)(n)). Scientists are working hard to develop efficient artificial photosynthetic systems toward the "Holy Grail" of solar-driven water splitting. High on the list of challenges is the discovery of molecules that efficiently catalyze the reduction of protons to ...

Electrochemical molecular catalyst screening (EMoCS) has been developed. This technique allows fast analysis and identification of homogeneous catalytic species through tandem catalyst assembly and electrochemistry. EMoCS has been used to study molecular proton reduction catalysts made from earth abundant materials to improve their viability for water splitting systems. The efficacy of EMoCS is...

The electrocatalytic proton reduction activity of a Ni bis(diphosphine) (NiP) and a cobaloxime (CoP) catalyst has been studied in water in the presence of the gaseous inhibitors O2 and CO. CoP shows an appreciable tolerance towards O2, but its activity suffers severely in the presence of CO. In contrast, NiP is strongly inhibited by O2, but produces H2 under high CO concentrations.

Post synthetically-modified UiO-66-NH 2 with a molecular cobaloxime [Co(DMG) Cl ] (DMG = dimethylglyoxime) catalyst displays excellent photo-(404 μmol g −1 h ) and electrocatalytic H evolution activity in an aqueous solution.

In the title compound, [Co(C(4)H(7)N(2)O(2))(2)Cl(C(8)H(9)NO(2))], which was prepared as a model complex of vitamin B(12), the Co(III) atom, which is linked to four N atoms of the pseudo-macrocyclic (dmgH)(2) ligand (dmgH is dimethyl-glyoximate) in the equatorial plane and one Cl(-) anion and one N atom of ethyl nicotinate in apical positions, displays an approximately octa-hedral coordination....

Quantum yield values up to 16% under visible irradiation associated with high turnover frequencies ( approximately 50 h(-1)) and stability (up to 273 turnovers), characterize the new photocatalytic systems for hydrogen production, based on diimine derivatives of ruthenium, cyclometallated iridium or tricarbonylrhenium as photosensitizers and cobaloxime H2-evolving catalytic centers, which are a...