nitrogen-dioxide and benzaldehyde

Benzylic alcohols are quantitatively oxidized by gaseous nitrogen dioxide to give pure aromatic aldehydes. The reaction gas mixtures are transformed to nitric acid, which renders the processes free of waste. The exothermic gas-liquid or gas-solid reactions profit from the solubility of nitrogen dioxide in the neat benzylic alcohols. The acid formed impedes further oxidation of the benzaldehydes. The neat isolated benzaldehydes and nitrogen dioxide quantitatively give the benzoic acids. Solid long-chain primary alcohols are directly and quantitatively oxidized with nitrogen dioxide gas to give the fatty acids in the solid state. The oxidations with ubiquitous nitrogen dioxide are extended to solid heterocyclic thioamides, which gives disulfides, and to diphenylamine, which gives tetraphenylhydrazine. These sustainable (green) specific oxidation procedures produce no dangerous residues from the oxidizing agent or from auxiliaries.

Topics: Alcohols; Aldehydes; Benzaldehydes; Diphenylamine; Fatty Acids; Gases; Green Chemistry Technology; Ketones; Nitrogen Dioxide; Oxidation-Reduction; Substrate Specificity; Thioamides

Upon exposure to sunlight, or to artificial light at wavelengths longer than 290 nm, sulfur dioxide in air underwent oxidation to give sulfur trioxide in the presence of air pollutants such as biacetyl (2,3-butanedione), benzaldehyde and nitrogen dioxide, but not in their absence. Only nitrogen dioxide completely oxidized sulfur dioxide to sulfur trioxide.

Topics: Air Pollutants; Benzaldehydes; Diacetyl; Environmental Exposure; Environmental Monitoring; Nitrogen Dioxide; Oxidation-Reduction; Photochemistry; Sulfur Dioxide; Sulfur Oxides; Sunlight