540-67-0Relevant articles and documents
Four Isomers of +. Distinguished by Collisional Activation
Crow, Frank W.,Gross, Michael L.,Bursey, Maurice M.
, p. 309 - 311 (1981)
Collisional activation of the molecular ions of 1-propanol, 2-propanol and methyl ethyl ether, and of the m/z 60 ion from 1,2-dimethoxyethane provides evidence for four distinct forms of +..Collision induced decompositions may be explained either by simple cleavages, by cyclic processes involving adjacent substituents, or by bicyclic processes of adjacent substituents.Evidence for a form of +. in which charge and radical site are separate is assembled from the spectra.
Solvent effect on reaction rates: Reaction between sodium ethoxide and methyl iodide in ethanol + cyclohexane solvent systems
Papanastasiou,Papoutsis,Tsirtou,Ziogas
, p. 203 - 217 (1996)
kinetics of the reaction between sodium ethoxide and methyl iodide has been studied at 25°C in various cyclohexane-ethanol solvent mixtures with a cyclohexane content of 10 to 50% per volume. The determination of the rate constants at t = 0 were carried out by a new iterative method proposed in this investigation. The obtained results show that the reaction rate decreases with the increasing cyclohexane content. This behavior can be attributed to various solute-solvent interactions of electrostatic nature. On the other hand, the variation of ion and ion pairs rate constants with solvent composition permits the various salvation effects to be taken into account.
Influence of Boiling on the Radiolysis of Diglyme
Vlasov,Kholodkova,Ponomarev
, p. 312 - 318 (2018/08/01)
The radiolysis of diethylene glycol dimethyl ether (diglyme) in a boiling state has been studied for the first time. Boiling facilitates the cleavage of internal C–O bonds, weakens the cage effect and diglyme regeneration processes, and facilitates the exchange and dimerization reactions of radicals. As compared with radiolysis at room temperature, the amount of unsaturated products of diglyme fragmentation formed during irradiation in the boiling state is smaller by a factor of 4, and the disproportionation products of heavy radicals are found in negligible amounts, if any. The yield of radiolytic decomposition of diglyme under boiling conditions is ～15 molecule/100 eV, which is higher than that at room temperature by a factor of almost 1.5.
Atmospheric Chemistry of CH3CH2OCH3: Kinetics and Mechanism of Reactions with Cl Atoms and OH Radicals
Sulbaek Andersen, Mads P.,Svendsen, Sissel Bj?rn,?sterstr?m, Freja From,Nielsen, Ole John
, p. 10 - 20 (2016/11/30)
The atmospheric chemistry of methyl ethyl ether, CH3CH2OCH3, was examined using FT-IR/relative-rate methods. Hydroxyl radical and chlorine atom rate coefficients of k(CH3CH2OCH3+OH) = (7.53 ± 2.86) × 10?12 cm3 molecule?1 s?1 and k(CH3CH2OCH3+Cl) = (2.35 ± 0.43) × 10?10 cm3 molecule?1 s?1 were determined (297 ± 2 K). The Cl rate coefficient determined here is 30% lower than the previous literature value. The atmospheric lifetime for CH3CH2OCH3 is approximately 2 days. The chlorine atom–initiated oxidation of CH3CH2OCH3 gives CH3C(O)H (9 ± 2%), CH3CH2OC(O)H (29 ± 7%), CH3OC(O)H (19 ± 7%), and CH3C(O)OCH3 (17 ± 7%). The IR absorption cross section for CH3CH2OCH3 is (7.97 ± 0.40) × 10?17 cm molecule?1 (1000–3100 cm?1). CH3CH2OCH3 has a negligible impact on the radiative forcing of climate.
Mild partial deoxygenation of esters catalyzed by an oxazolinylborate-coordinated rhodium silylene
Xu, Songchen,Boschen, Jeffery S.,Biswas, Abhranil,Kobayashi, Takeshi,Pruski, Marek,Windus, Theresa L.,Sadow, Aaron D.
, p. 15897 - 15904 (2015/09/15)
An electrophilic, coordinatively unsaturated rhodium complex supported by borate-linked oxazoline, oxazoline-coordinated silylene, and N-heterocyclic carbene donors [{κ3-N,Si,C-PhB(OxMe2)(OxMe2SiHPh)ImMes}Rh(H)CO][HB(C6F5)3] (2, OxMe2 = 4,4-dimethyl-2-oxazoline; ImMes = 1-mesitylimidazole) is synthesized from the neutral rhodium silyl {PhB(OxMe2)2ImMes}RhH(SiH2Ph)CO (1) and B(C6F5)3. The unusual oxazoline-coordinated silylene structure in 2 is proposed to form by rearrangement of an unobserved isomeric cationic rhodium silylene species [{PhB(OxMe2)2ImMes}RhH(SiHPh)CO][HB(C6F5)3] generated by H abstraction. Complex 2 catalyzes reductions of organic carbonyl compounds with silanes to give hydrosilylation products or deoxygenation products. The pathway to these reactions is primarily influenced by the degree of substitution of the organosilane. Reactions with primary silanes give deoxygenation of esters to ethers, amides to amines, and ketones and aldehydes to hydrocarbons, whereas tertiary silanes react to give 1,2-hydrosilylation of the carbonyl functionality. In contrast, the strong Lewis acid B(C6F5)3 catalyzes the complete deoxygenation of carbonyl compounds to hydrocarbons with PhSiH3 as the reducing agent.
Investigating the α-effect in gas-phase SN2 reactions of microsolvated anions
Thomsen, Ditte L.,Reece, Jennifer N.,Nichols, Charles M.,Hammerum, Steen,Bierbaum, Veronica M.
, p. 15508 - 15514 (2013/11/06)
The α-effect - enhanced reactivity of nucleophiles with a lone-pair adjacent to the attacking center - was recently demonstrated for gas-phase SN2 reactions of HOO-, supporting an intrinsic component of the α-effect. In the present work we explore the gas-phase reactivity of microsolvated nucleophiles in order to investigate in detail how the α-effect is influenced by solvent. We compare the gas-phase reactivity of the microsolvated α-nucleophile HOO-(H2O) to that of microsolvated normal alkoxy nucleophiles, RO-(H2O), in reaction with CH3Cl using a flowing afterglow-selected ion flow tube instrument. The results reveal enhanced reactivity of HOO-(H 2O) and clearly demonstrate the presence of an α-effect for the microsolvated α-nucleophile. The association of the nucleophile with a single water molecule results in a larger Bronsted βnuc value than is the case for the unsolvated nucleophiles. Accordingly, the reactions of the microsolvated nucleophiles proceed through later transition states in which bond formation has progressed further. Calculations show a significant difference in solvent interaction for HOO- relative to the normal nucleophiles at the transition states, indicating that differential solvation may well contribute to the α-effect. The reactions of the microsolvated anions with CH3Cl can lead to formation of either the bare Cl- anion or the Cl-(H2O) cluster. The product distributions show preferential formation of the Cl- anion even though the formation of Cl-(H2O) would be favored thermodynamically. Although the structure of the HOO-(H2O) cluster resembles HO-(HOOH), we demonstrate that HOO- is the active nucleophile when the cluster reacts.
A novel sol-gel approach to highly condensed silicas at low temperature
Jorapur, Yogesh R.,Mizoshita, Norihiro,Maegawa, Yoshifumi,Nakagawa, Hiroki,Hasegawa, Takeru,Tani, Takao,Inagaki, Shinji,Shimada, Toyoshi
supporting information; scheme or table, p. 280 - 281 (2012/05/31)
We have discovered new Meerwein's reagent-catalyzed solgel polycondensations, which provide highly condensed silica Q4 and biphenylylene silica T3 as amorphous gels with marginal silanols starting from TEOS and 4,4′-bis(triethoxysilyl)biphenyl (BTEBph), respectively. We propose a plausible pathway for this protocol with possible silyloxonium intermediates.
Vapor generation of inorganic anionic species after aqueous phase alkylation with trialkyloxonium tetrafluoroborates
D'Ulivo, Alessandro,Pagliano, Enea,Onor, Massimo,Pitzalis, Emanuela,Zamboni, Roberto
scheme or table, p. 6399 - 6406 (2010/04/06)
Aqueous phase reaction of trialkyloxonium tetrafluoroborates, R 3O+BF4- (R=Me, Et) has been tested in the alkylation of simple inorganic anionic substrates such as halogen ions, cyanide, thiocyanate, sulphide an
Methanol and fuel alcohol production for an oxygenate to olefin reaction system
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Page/Page column 10-12, (2008/06/13)
The present invention provides various processes for producing C1 to C4 alcohols, optionally in a mixed alcohol stream, and optionally converting the alcohols to light olefins. In one embodiment, the invention includes directing a first portion of a syngas stream to a methanol synthesis zone wherein methanol is synthesized. A second portion of the syngas stream is directed to a fuel alcohol synthesis zone wherein fuel alcohol is synthesized. The methanol and at least a portion of the fuel alcohol are directed to an oxygenate to olefin reaction system for conversion thereof to ethylene and propylene.
Reaction network of aldehyde hydrogenation over sulfided Ni-Mo/Al 2O3 catalysts
Wang, Xueqin,Saleh, Ramzi Y.,Ozkan, Umit S.
, p. 20 - 32 (2007/10/03)
A reaction network of aldehyde hydrogenation over NiMoS/Al 2O3 catalysts was studied with aldehydes with straight and branched carbon chains and different chain lengths as feed materials. The reactions in the gas phase and the liquid phase were compared. The main reaction in the aldehyde hydrogenation process is the hydrogenation of the CO double bond, which takes place over the coordinatively unsaturated sites. The major side reactions are self-condensation of aldehydes and condensation of aldehydes with alcohols. Both reactions involve α-hydrogen and are primarily catalyzed by acid-base bifunctional sites over the exposed Al2O 3 surfaces.
