Photochemical reactions contribute in a significant way to the existing repertoire of carbon-carbon bond-forming reactions by allowing access to exceptional molecular structures that cannot be obtained by conventional means. In this Review, the most important photochemical transformations that have been employed in natural product synthesis are presented. Selected total syntheses are discussed ...

Seoul is one of the most severe smoggy cities in the world. During summer afternoons, the fine particles formed by photochemical reactions could contribute visibility reduction. The formation and growth of secondary ambient aerosols might be affected by primary air pollutants and by meteorological factors. In this work, the photochemical reaction of Seoul ambient air was investigated in indoor ...

A new molybdenum porphycene complex, which is a new complex having oxo and chloro groups at the axial positions, was successfully synthesized. This chloro(oxo)molybdenum(v) complex, [Mo(V)(OEPc)(O)Cl] (1) has strong absorption bands in the visible region attributed to the properties of the porphycene and is very attractive from a photochemical viewpoint. This complex was readily reduced from Mo...

A quantum yield of •i•e = 2.3 x 10 '4 (+_ 4 X 10 -•) was determined for the photochemical degradation of 4nitrophenol over the wavelength range of 300 to 370 nm in ice pellets (pH 5.6). Five reaction products were identified: hydroquinone, benzoquinone, 4-nitrosophenol, nitrate, nitrite, and the likely formation of organic polymers. The similarities of these results to the observations from 4-n...

The hydroperoxyl radical (HO2) is one of the most abundant free radicals in the atmosphere, where it participates in a series of photochemical reactions that determine the fate of natural and anthropogenic emissions. In addition, HO2 is found in droplets and surface water as a result of photochemical formation and gas-phase scavenging. We describe a quantitative method for determining trace con...

Common sources of chromium in wastewater are electroplating and leather industries. Hexavalent chromium is more toxic and carcinogenic compared to its trivalent counterpart. Conversion of Cr (VI) to Cr (III) in an aqueous medium both by chemical reduction using zerovalent iron and by photocatalytic reduction using UV radiation and ZnO semiconductor has been investigated using potassium dichroma...