V. I. Maryasova, A. S. Zanina, A. Kruppa
Oct 15, 1991
Citations
0
Influential Citations
4
Citations
Journal
Journal of Photochemistry and Photobiology A-chemistry
Abstract
Abstract Photoirradiation of 3-phenyl-1- p -tolyl-2-propyne-1-one ( I ), 1,3-diphenyl-2-propyne-1-one ( II ), 4-methyl-4-methoxy-1- p -tolyl-2-butyne-1-one ( III ), 2,2-dimethyl-5-pehynl-4-pentyne-3-one ( IV ) and 2,2,6-trimethyl-6-methoxy-4-dodecyne-3-one ( V ) in the presence of hydrogen and electron donors (cyclohexane)- d 12 , isopropanol, triethylamine) in various solvents (cyclohexane- d 12 , deuteroacetonitrile, deuterobenzene) was studied using 1 H chemically induced dynamic nuclear polarization. It has been found that the reaction proceeds via the photoreduction of ketones in the case of the presence of an aromatic substitutent at the carbonyl group ( I – III ). Moreover, it involves two reaction centres: carbon atoms of carbonyl and acetylene groups. Photodecomposition via Norrish type 1 cleavage occurs in the case of aliphatic substituents ( IV , V ).