3166-15-2Relevant academic research and scientific papers
Redox properties and radical anions of 2-substituted thioxanthen-9-ones and their 2-methyl S-oxide derivatives
Vasilieva, Nadezhda V.,Irtegova, Irina G.,Loskutov, Vladimir A.,Shundrin, Leonid A.
, p. 334 - 336 (2013)
The electrochemical reduction of 2-substituted thioxanthen-9-ones in MeCN is a one-electron process with the formation of long-lived radical anions, in which the thioxanthen-9-one fragment is planar according to EPR measurements and UB3LYP/6-31+G* calculations. The electrochemical reduction of 2-methylthioxanthen-9-one sulfoxide and sulfone are EEC and EE processes, respectively, their radical anions are not planar, and the electrochemical oxidation of the title compounds is irreversible with consecutive oxidation of the sulfur atom, except for the sulfone, whose oxidation was not observed at the limit of the anodic potential (2.5 V vs. s.c.e.).
Synthesis of 1,2-Dioxetanes as Thermochemiluminescent Labels for Ultrasensitive Bioassays: Rational Prediction of Olefin Photooxygenation Outcome by Using a Chemometric Approach
Andronico, Luca A.,Quintavalla, Arianna,Lombardo, Marco,Mirasoli, Mara,Guardigli, Massimo,Trombini, Claudio,Roda, Aldo
supporting information, p. 18156 - 18168 (2016/12/16)
Great interest in new thermochemiluminescent (TCL) molecules, for example, in bioanalytical assays, has prompted the design and synthesis of a small library of more than 30 olefins to be subjected to photooxygenation, with the aim of obtaining new 1,2-dioxetane-based TCL labels with optimized properties. Fluorine atoms on the acridan system remarkably stabilize 1,2-dioxetanes when they are located in the 3- and/or 6-position (4 h and 4 i). On the other hand, 2,7-difluorinated acridan dioxetane (4 j) showed a significantly enhanced fluorescence quantum yield with respect to the unsubstituted dioxetane (4 a). Some of the synthesized olefins did not undergo singlet oxygen addition and a rationale was sought to ease the photooxygenation step, leading to the TCL dioxetanes. A chemometric approach has been adopted to exploit principal component analysis and linear discriminant analysis of the structural and electronic molecular descriptors obtained by DFT optimizations of olefins 3. This approach allows the steric and electronic parameters that govern dioxetane formation to be revealed.
Oxygen-17 N.M.R. Spectra of C(2)-Substituted Thioxanthones, Thioxanthone Sulphoxide, and Thioxanthone Sulphone
Harwood, John S.,Ternay, Andrew L.
, p. 1657 - 1660 (2007/10/02)
The 17O n.m.r. spectra of a series of 17O-enriched 2-substituted thioxanthen-9-ones are reported.Analysis of the 17O chemical shifts using the dual substituent parameter (DSP) method shows that the carbonyl oxygen chemical shift correlates precisely with ?l and ?R(+) even though the carbonyl group is meta to the C(2)-substituent; interaction between them is apparently mediated by the heterocyclic sulphur.The carbonyl 13C chemical shifts do not correlate well with the C(2)-substituent.Enrichment with oxygen-17 was accomplished using 17O-enriched water in hydrochloric acid-dioxane.Under these conditions, thioxanthenone S-oxide reacts to produce small amounts of enriched thioxanthenone and thioxanthenone S,S-dioxide in addition to enriched starting material.
Synthesis of o-Substituted Phenols by Criegee Rearrangement of Benzylic Hydroperoxides
Taljaard, Benjamin,Goosen, Andre,McCleland, Cedric W.
, p. 931 - 934 (2007/10/02)
9-Phenylthioxanthen-9-ol, 10,10-dimethyl-9-phenyl-9,10-dihydroanthracen-9-ol, and 9-arylfluoren-9-ols undergo Criegee-type rearrangements when treated with hydrogen peroxide and acid to generate substituted benzophenones from the first two substrates, and monoesters of biphenyl-2,2'-diol from the fluorenes via subsequent Bayer-Villiger oxidation of the intermediate 2'-aroylbiphenyl-2-ol. 5-Phenyl-10,11-dihydrodibenzocyclohepten-5-ol and its dehydroderivative gave the corresponding heptanone and heptenone on treatment with acid and hydrogen peroxide.Prolonged reaction of the 5-phenyldibenzohepten-5-ol afforded products arising from oxidation of the double bond.
OXIDATION OF SULFIDES TO SULFOXIDES BY 1-ACETYL-v-TRIAZOLOPYRIDINE/HYDROGEN PEROXIDE SYSTEM
Torrini, Ines,Paradisi, Mario Paglialunga,Zecchini, Giampiero Pagani,Agrosi, Francesco
, p. 515 - 520 (2007/10/02)
Dialkyl, diaryl, and mixed alkyl aryl sulfides are convertd to sulfoxides in high yield by the use of the 1-acetyl-v-triazolopyridine/hydrogen peroxide biphasic system.
Determination of Rate Constants for Electron Transfer from Radical Anions of Aromatic Compounds to Diaryl Disulfides
Tagaya, Hideyuki,Aruga, Tamotsu,Ito, Osamu,Matsuda, Minoru
, p. 5484 - 5489 (2007/10/02)
Rate constants for electron transfer from the radical anions of aromatic compounds to diaryl disulfides (ArSSAr) have been determined in tetrahydrofuran.By the change of the reduction potentials of the aromatic compounds from -1.04 to -1.91 V (vs.SCE), the rate constants varied from 0.015 to 2.3 * 108 M-1 s-1; conventional spectrophotometry has been employed to measure the slow reaction rates, and the xenon-flash photolysis technique has been applied to the fast reaction systems.The reaction including the free ion or the loose ion pair of the thioxanthone sulfone radical anion, (TO-SO2)-/., was faster than that including the tight ion pair.In the case of the (TO-SO2)-/., Na+-PhSSPh system, temperature variation yielded the free energy of activation (ΔG* = 18.7 kcal/mol) and activation enthropy (ΔS* = -29.1 eu) at 22.4 deg C; the reduction potential of PhSSPh was estimated to be -1.80 V vs.SCE from ΔG* value.Electron-withdrawing substituents of ArSSAr increase the rates and vice versa; the Hammett reaction constants (ρ) were estimated to be ca. +1.50 and 1.40 for electron transfer from perylene radical anion and (TO-SO2)-/.,Na+ to ArSSAr, respectively.The factors controlling the rates have been examined.
