Reference

Kinetics of the type I photocleavage of aliphatic ketones

Kinetics of the type I photocleavage of aliphatic ketones. Abuin, E.; Lissi, E. A.In this study， 815-24-7 and 565-69-5 are also used. (Dep. Quim., Univ. Tec. Estado, Santiago, Chile). J. Photochem., 6(1), 1-8 (English) 1976. CODEN: JPCMAE. DOCUMENT TYPE: Journal CA Section: 22 (Physical Organic Chemistry) The triplet lifetime of Me2CHCOEt was detd. at several temps. employing naphthalene as triplet quencher. The rate const. for the type I photocleavage of the triplet state is given by: log k (s-1) = 13.5 - 7200/4.6 T. The kinetic behavior of the singlet excited state of tert-Bu ketones was investigated by measuring the fluorescence quantum yield between 15 and 80.degree.. The data showed that the photocleavage from the excited singlet occurs with low activation energies and with preexponential factors lower than 109 s-1. The differences between both sets of data, as well as previous data obtained in the thermal and hot photocleavage of excited ketones, are discussed in terms of state correlation diagrams. .

Synthesis and antimalarial activities of novel 3,3,6,6-tetraalkyl-1,2,4,5-tetraoxanes

All Rights Reserved. Synthesis and antimalarial activities of novel 3,3,6,6-tetraalkyl-1,2,4,5-tetraoxanes. Zmitek, Katja; Stavber, Stojan; Zupan, Marko; Bonnet-Delpon, Daniele; Charneau, Sebastien; Grellier, Phillipe; Iskra, Jernej (Laboratory of Organic and Bioorganic Chemistry, 'Jozef Stefan' Institute and Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana 1000, Slovenia). Bioorganic & Medicinal Chemistry, 14(23), 7790-7795 (English) 2006 Elsevier Ltd. CODEN: BMECEP. ISSN: 0968-0896. DOCUMENT TYPE: Journal CA Section: 1 (Pharmacology) Section cross-reference(s): 28 The oxidative system H2O2/fluorinated alc. (TFE, HFIP) was used for direct acid- and MeReO3-catalyzed synthesis of 1,2,4,5-tetraoxanes from cyclic (C6, C7, and C12) and acyclic ketones. The influence of ring size and alkyl chain length were studied and antimalarial activities of synthetic 3,3,6,6-tetraalkyl-1,2,4,5-tetraoxanes were detd. Variations in their antimalarial activities were significant, although they share similar electrochem. properties of the peroxide bond.Except for chemicals metioned above, 565-69-5 is also used. .