460-12-8Relevant academic research and scientific papers
Site-Selective N-Dealkylation of 1,2,3-Triazolium Salts: A Metal-Free Route to 1,5-Substituted 1,2,3-Triazoles and Related Bistriazoles
Monasterio, Zaira,Irastorza, Aitziber,Miranda, José I.,Aizpurua, Jesus M.
supporting information, p. 2511 - 2514 (2016/06/09)
N3-Alkylation of 1-(pivaloyloxymethyl)-1,2,3-triazoles with alkyl triflates carrying latent "click" functionality, followed by a nucleophile-promoted N1-dealkylation of the resulting strongly electrophilic intermediate triazolium salts, provides an efficient route to 1,5-disubstituted 1,2,3-triazoles. The azide and alkyne groups incorporated by N-alkylation can be submitted to further copper-catalyzed azide-alkyne and Huisgen cycloadditions to provide bis(1,2,3-triazoles) with unprecedented 1,5/1,4 substitution patterns.
Synthesis of Diphenylchalcogenophene Diboronic Acid Bis(pinacol) Esters and Halogen Photoelimination from Tellurium by Triplet–Triplet Annihilation
Li, Peng-Fei,Carrera, Elisa I.,Seferos, Dwight S.
, p. 917 - 921 (2016/09/13)
The synthesis of diphenylthiophene-, diphenylselenophene-, and diphenyltellurophene-based diboronic bis(pinacol) esters and their optoelectronic properties is reported. The addition of bromine to the borylated diaryltellurophene and subsequent photoelimination are investigated. The photochemical quantum yield of bromine photoelimination is (9.7±0.2) % at a 4.4 m trap (2,3-dimethyl-1,3-butadiene) concentration. It is found that the bromine photoelimination reaction can also be driven by the incorporation of a triplet sensitizer through a triplet–triplet annihilation process.
Kinetics of the reactions of hydroxyl radicals with diacetylene and vinylacetylene
Sommerer, J?rg,Olzmann, Matthias
, p. 495 - 505 (2015/04/14)
Highly unsaturated hydrocarbons like diacetylene (C4H2) or vinylacetylene (C4H4) are important intermediates in combustion that can have impact on soot formation. One of their major loss channels is reaction with hydroxyl radicals (OH). We studied the reactions C4H2 + OH → products (1) and C4H4 + OH → products (2) in a quasi-static reactor with helium as bath gas. The hydroxyl radicals were produced by laser flash-photolysis of nitric acid at a wavelength of 248 nm and detected by laser-induced fluorescence with excitation at 282 nm. The rate coefficients were obtained from the intensity-time profiles under pseudo-first order conditions with respect to OH. We found a virtually temperature-independent rate coefficient for reaction (1): k1 = (1.0 ± 0.3) × 10-11 cm3 s-1 (T = 290-670 K, P = 2.7-30.5 bar) and a weakly negative temperature-dependent rate coefficient for reaction (2): k2(T) = (6.4 ± 1.9) × 10-12 exp (486 K/T) cm3 s-1 (T = 295-740 K, P = 1.7-19.2 bar). For neither of the two reactions pressure dependence was observed. From comparisons with analogous reaction systems, we conclude that the dominating reaction pathway is OH addition, where in the case of C4H4 the double bond is preferred over the triple bond.
METHODS OF PRODUCING DICARBONYL COMPOUNDS
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Paragraph 0038, (2015/05/06)
Dicarboxylic acids, such as adipic acid, and diesters, such as adipates, may be produced by hydrogenating alkynes that may be produced from raw materials salvaged from waste stream processes. The carbons of the dicarboxylic acids are provided by alkynes generated from biomass waste and carbon dioxide recovered from waste streams such as exhaust gases.
Formation of fulvene in the reaction of C2H with 1,3-butadiene
Lockyear, Jessica F.,Fournier, Martin,Sims, Ian R.,Guillemin, Jean-Claude,Taatjes, Craig A.,Osborn, David L.,Leone, Stephen R.
, p. 232 - 245 (2015/04/14)
Abstract Products formed in the reaction of C2H radicals with 1,3-butadiene at 4 Torr and 298 K are probed using photoionization time-of-flight mass spectrometry. The reaction takes place in a slow-flow reactor, and products are ionized by tunable vacuum-ultraviolet light from the Advanced Light Source. The principal reaction channel involves addition of the radical to one of the unsaturated sites of 1,3-butadiene, followed by H-loss to give isomers of C6H6. The photoionization spectrum of the C6H6 product indicates that fulvene is formed with a branching fraction of (57 ± 30)%. At least one more isomer is formed, which is likely to be one or more of 3,4-dimethylenecyclobut-1-ene, 3-methylene-1-penten-4-yne or 3-methyl-1,2-pentadien-4-yne. An experimental photoionization spectrum of 3,4-dimethylenecyclobut-1-ene and simulated photoionization spectra of 3-methylene-1-penten-4-yne and 3-methyl-1,2-pentadien-4-yne are used to fit the measured data and obtain maximum branching fractions of 74%, 24% and 31%, respectively, for these isomers. An upper limit of 45% is placed on the branching fraction for the sum of benzene and 1,3-hexadien-5-yne. The reactive potential energy surface is also investigated computationally. Minima and first-order saddle-points on several possible reaction pathways to fulvene + H and 3,4-dimethylenecyclobut-1-ene + H products are calculated.
Electronic coupling mediated by furan, thiophene, selenophene and tellurophene in a homologous series of organic mixed valence compounds
Jahnke, Ann Christin,Spulber, Mariana,Neuburger, Markus,Palivan, Cornelia G.,Wenger, Oliver S.
supporting information, p. 10883 - 10886 (2014/10/15)
Charge delocalization in the mixed-valent monocationic forms of phenothiazine-decorated chalcogenophenes is explored by cyclic voltammetry, optical absorption and EPR spectroscopy. Single units of furan, thiophene, selenophene and tellurophene are found to mediate electronic coupling between the phenothiazines attached to their 2- and 5-positions roughly equally well. Electronic communication seems to occur mostly through the butadiene-like backbone of the chalcogenophenes. the Partner Organisations 2014.
Partially oxidized gold nanoparticles: A catalytic base-free system for the aerobic homocoupling of alkynes
Boronat, Mercedes,Laursen, Siris,Leyva-Perez, Antonio,Oliver-Meseguer, Judit,Combita, Diego,Corma, Avelino
, p. 6 - 14 (2014/05/20)
The mechanism of alkyne homocoupling over gold nanoparticles and clusters, isolated and supported on CeO2, has been theoretically investigated by means of periodic DFT calculations. The theoretical study indicates that O2 dissociation on gold generates basic O atoms able to abstract the proton of the alkyne, and cationic Auδ+ and Au+ species that decrease the activation barrier for the CC bond forming step. Kinetic results show that the base-free homocoupling of alkynes is effectively catalyzed by gold nanoparticles supported on different solids, and confirm the theoretical prediction that the dissociation of oxygen on the gold nanoparticle is the controlling step of the global reaction.
Pyridyl-and pyridylperoxy radicals-a matrix isolation study
Korte, Andre,Mardyukov, Artur,Sander, Wolfram
, p. 1324 - 1329 (2014/11/07)
The three isomeric pyridyl radicals 2a-c were synthesised using flash vacuum pyrolysis in combination with matrix isolation and characterised by infrared spectroscopy. The IR spectra are in good agreement with spectra calculated using density functional theory methods. The reaction of the pyridyl radicals 2 with molecular oxygen leads to the formation of the corresponding pyridylperoxy radicals 3a-c. The peroxy radicals 3 are photolabile, and irradiation results in syn-anti isomerisation of 3a and 3b and ring expansion of all three isomers of 3.
A novel tellurophene-containing conjugated polymer with a dithiophenyl diketopyrrolopyrrole unit for use in organic thin film transistors
Kaur, Matinder,Seul Yang, Da,Shin, Jicheol,Wan Lee, Tae,Choi, Kihang,Ju Cho, Min,Hoon Choi, Dong
supporting information, p. 5495 - 5497 (2013/06/27)
A new tellurophene-based π-conjugated polymer, PDTDPPTe, was synthesized. PDTDPPTe exhibits a smaller optical band gap (Eg opt = 1.25 eV) than thiophene-based PDTDPPT (Eg opt = 1.30 eV). Thin-film transistors comprising PDTDPPTe displayed outstanding performance (μmax = 1.78 cm2 V-1 s-1, Ion/Ioff = 105-6).
Reaction rate and isomer-specific product branching ratios of C 2H + C4H8: 1-butene, cis -2-butene, trans -2-butene, and isobutene at 79 K
Bouwman, Jordy,Fournier, Martin,Sims, Ian R.,Leone, Stephen R.,Wilson, Kevin R.
, p. 5093 - 5105 (2013/07/25)
The reactions of C2H radicals with C4H8 isomers 1-butene, cis-2-butene, trans-2-butene, and isobutene are studied by laser photolysis-vacuum ultraviolet mass spectrometry in a Laval nozzle expansion at 79 K. Bimolecular-reaction rate constants are obtained by measuring the formation rate of the reaction product species as a function of the reactant density under pseudo-first-order conditions. The rate constants are (1.9 ± 0.5) × 10-10, (1.7 ± 0.5) × 10 -10, (2.1 ± 0.7) × 10-10, and (1.8 ± 0.9) × 10-10 cm3 s-1 for the reaction of C2H with 1-butene, cis-2-butene, trans-2-butene, and isobutene, respectively. Bimolecular rate constants for 1-butene and isobutene compare well to values measured previously at 103 K using C2H chemiluminescence. Photoionization spectra of the reaction products are measured and fitted to ionization spectra of the contributing isomers. In conjunction with absolute-ionization cross sections, these fits provide isomer-resolved product branching fractions. The reaction between C2H and 1-butene yields (65 ± 10)% C4H4 in the form of vinylacetylene and (35 ± 10)% C5H6 in the form of 4-penten-1-yne. The cis-2-butene and trans-2-butene reactions yield solely 3-penten-1-yne, and no discrimination is made between cis- and trans-3-penten-1-yne. Last, the isobutene reaction yields (26 ± 15)% 3-penten-1-yne, (35 ± 15)% 2-methyl-1-buten-3-yne, and (39 ± 15)% 4-methyl-3-penten-1-yne. The branching fractions reported for the C2H and butene reactions indicate that these reactions preferentially proceed via CH3 or C2H3 elimination rather than H-atom elimination. Within the experimental uncertainties, no evidence is found for the formation of cyclic species.
