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The insoluble yellow powder of poly(p-phenylene) (PPP) prepared by nickel-catalyzed polycondensation of the Grignard reagent from 1,4-dibromobenzene shows photocatalytic activity under visible light toward water, carbonyl compounds, and olefins. Water is photoreduced to H{sub 2} in the presence of amines as sacrificial electron donors. The H{sub 2} evolution is enhanced 3-20 times by noble-metal deposition, in which Ru deposition is the most effective.

Photocatalytic CO 2 -fixation using [Re(bpy)(CO) 3 L]+ [bpy = 2,2′-bipyridine, L = P( n -Bu) 3 (1), PEt 3 (2), PPh 3 (3), P(OMe)Ph 2 (4), P(O i -Pr) 3 (5), P(OEt) 3 (6)]was examined by electrospray mass spectrometry and high performance liquid chromatography. The complexes 1, 2, 4, 5 and 6 remained at close to initial levels during the catalytic CO formation and a formate complex Re(bpy)(CO) 3 OC(O)H (7) was detected after prolonged irradiation. On the other hand, 3 changed completely to solvent (DMF, triethanolamine) complexes with a quantum yield of >>1 before catalytic CO formation, followed by the generation of 7. The ligand exchanges with solvent molecules were explained in terms of a chain reaction mechanism.

The high-performance liquid chromatography of fourteen rhenium complexes with phosphorus and 2,2′-bipyridine-derivative ligands has been examined. Good separation between these complexes was achieved by use of an ODS column with a 60∶40 (v/v) mixture of MeOH and KH2PO4-NaOH buffer as mobile phase. Linear correlations were observed between the capacity factors of the mono-phosphorus complexes and Fujita's organicity/inorganicity ratios for the phosphorus ligands, revealing that Fujita's organicity/inorganicity parameters are useful for evaluating of the retention behavior of these complexes.

International audience; Photoelectrochemical CO2 reduction activity of a hybrid photocathode, based on a Ru(II)-Re(I) supramolecular metal complex photocatalyst immobilized on a NiO electrode (NiO-RuRe) was confirmed in an aqueous electrolyte solution. Under half-reaction conditions, the NiO-RuRe photocathode generated CO with high selectivity, and its turnover number for CO formation reached 32 based on the amount of immobilized RuRe. A photoelectrochemical cell comprising a NiO-RuRe photocathode and a CoOx/TaON photoanode showed activity for visible-light-driven CO2 reduction using water as a reductant to generate CO and O2, with the assistance of an external electrical (0.3 V) and chemical bias (0.10 V) produced by a pH difference. This is the first example of a molecular and semiconductor photocatalyst hybrid-constructed photoelectrochemical cell for visibl-light-driven CO2 reduction using water as a reductant.

Irradiation of [fac-Re(bpy)(CO)3Br] and triethylamine in N,N-dimethylformamide resulted in photobleaching of the complex to give the 5-ethyl-2,2′-bipyridine complex (2), the formation of which was affected by either Br– or water.

Magnesium(II) ion catalyses the photosensitised reduction of carbon–carbon double bonds of dimethyl fumarate, derivatives of methyl cinnamate, and some other related olefins by 1-benzyl-1, 4-dihydro-nicotinamide (BNAH), which proceeds via sequential two-electron transfer initiated by the photo-excitation of [Ru(bpy)3]2+(bpy = 2,2′-bipyridine). The metal ion forms a complex with BNAH in methanol as well as in 10:1 (v/v) pyridine–methanol, leading to the retardation of electron transfer from BNAH to luminescent excited-state Ru(ppy)32+. The net metal-ion effects arise from the catalysis of both the first and second one-electron reduction processes.