Reaction Of Triethylamine Research Articles

Superior triethylamine-sensing properties based on SnO2 hollow nanospheres synthesized via one-step process

Due to serious harm of triethylamine (TEA) to environmental safety and human health, it is significant to synthesize gas-sensitive materials with high performance for TEA detection. However, it is still a challenge to achieve high-sensitivity detection of TEA at low temperature for a sensor synthesized through an economical and efficient method. In this work, hollow-structured SnO2 (HS-SnO2) nanospheres have been fabricated by a facile, low-cost hydrothermal method in one step, which exhibit superior TEA-sensing properties, including not only ultrahigh response (127.75) for 100 ​ppm TEA, good selectivity, but also fast response and recovery time (17/28 ​s), low detection threshold (1 ​ppm) and robust stability at a relatively low optimum operational temperature of 225 ​°C. The excellent gas-sensitizing performances are ascribed to porous hollow structures with rich oxygen vacancies that provide abundant active sites for raising O2 adsorption and reaction of TEA and oxygen species. This work offers an effective and economical strategy for fabricating high-performance TEA sensors for industrial applications.

Highly Efficient Autoxidation of Triethylamine.

Autoxidation has been acknowledged as a major oxidation pathway in a broad range of atmospherically important compounds including isoprene and monoterpenes. More recently, autoxidation has also been identified as central and even dominant in the atmospheric oxidation of the rather small nonhydrocarbons dimethyl sulfide (DMS) and trimethylamine (TMA). Here, we find even faster autoxidation in the aliphatic amine triethylamine (TEA). The atmospherically dominating autoxidation leads to highly oxygenated and functionalized compounds. Products with as many as three hydroperoxy (OOH) groups and an O:C ratio larger than 1 are formed. We present theoretical multiconformer transition-state theory (MC-TST) calculations of the unimolecular reactions in the autoxidation following the OH + TEA reaction and calculate peroxy radical H-shift rate coefficients >20 s-1 for the first two generations of H-shifts. The efficient autoxidation in TEA is verified by the observation of the proposed highly oxidized products and radicals in flow-tube experiments. We find that the initial OH hydrogen abstraction at the α-carbon is strongly favored, with the β-carbon abstraction yield being less than a few percent.

Dialkyl Succinates and Adipates as Alternative Plasticizers-Even More Efficient Synthesis.

As a result of strict regulations of phthalate plasticizers, alternative non-phthalate forms are desired and increasingly used. This work presents a synthetic method for alternative plasticizers (dialkyl succinates and adipates) via esterification of succinic and adipic acid with alcohols: butan-1-ol and 2-ethylhexan-1-ol. Ionic liquids were synthesized by the reaction of triethylamine with over-equimolar (1:2.7) amounts of sulfuric(VI) acid, which were used as an acidic catalyst and solvent. The two-phase liquid–liquid system was formed during the reaction due to immiscibility of the esters with the ionic liquid. This phenomenon is a driving force of this process, shifting the equilibrium toward the product formation. As a result, dialkyl succinates and adipates were obtained in high yields (99%) and selectivities (>99%), under mild reaction conditions at 70–80 °C and using a 4:1 molar ratio of alcohol to acid and 15 mol% of catalyst. The catalyst was recycled 10 times without any loss of activity. This alternative method is highly competitive: it involves a simple procedure for product isolation as well as a high yield and purity of the resulting esters. These advantages make this method sustainable and promising for industrial applications.

Double network hydrophobic starch based amphoteric hydrogel as an effective adsorbent for both cationic and anionic dyes

A double-network hydrophobic-hydrogel was successfully synthesized. Here epichlorohydrin (ECH) and N, N-methylene bis-acrylamide act as the crosslinkers for starch and poly(acrylic acid), respectively. The synthesized hydrogel having both positive and negative charge exhibited amphoteric properties and employed for the exclusion of anionic and cationic dyes from waste aqueous solution. The formation of positive charge occurs via reaction of triethylamine with the open up epoxy ring of ECH while carboxylate ion of poly(acrylic acid) gives the negative charge in the hydrogel. The formation of double cross-linking and the presence of quaternized alkyl chains lead towards hydrophobicity with much lower swelling ability. As an adsorbent, the hydrogel was able to remove both cationic dye (methylene blue) and anionic dye (congo red) with adsorption maxima of 133.65 mg/g and 64.73 mg/g, respectively. This study showed that the synthesized hydrogel offers enormous potential as the toxic dye adsorbent for effluent treatment of industrial wastewater.

Novel ionic liquid [Et3N-SO3H][MeSO3]: Synthesis, characterization and catalytic performance for the synthesis of 14-aryl-14H-dibenzo[a,j]xanthenes

The main aim of this work is introducing a novel protic acidic ionic-liquid catalyst for organic synthesis. Thus, N , N -diethyl- N -sulfoethanaminium methanesulfonate ([Et 3 N-SO 3 H][MeSO 3 ]) was synthesized by the reaction of triethylamine with chlorosulfonic acid, and then with methanesulfonic acid. The structure of this novel protic acidic ionic liquid was identified by FT-IR, 1 H NMR, 13 C NMR and mass spectral data. Its catalytic activity was examined for the solvent-free reaction of 2-naphthol with arylaldehydes to provide 14-aryl-14 H -dibenzo[ a , j ]xanthenes. [Et 3 N-SO 3 H][MeSO 3 ] efficiently catalyzed the reaction, and the products were obtained in high to excellent yields and in short reaction times. KEY WORDS : Protic acidic ionic liquid, N , N -Diethyl- N -sulfoethanaminium methanesulfonate ([Et 3 N-SO 3 H][MeSO 3 ]), 2-Naphthol, Arylaldehyde, 14-Aryl-14 H -dibenzo[ a , j ]xanthene Bull. Chem. Soc. Ethiop. 2019 , 33(1), 69-76 DOI: https://dx.doi.org/10.4314/bcse.v33i1.7

A fast and green preconcentration method based on surfactant ion pair-switchable solvent dispersive liquid–liquid microextraction for determination of phenazopyridine in pharmaceutical and biological samples

Herein, a novel, fast, green and sensitive surfactant ion pair-switchable solvent dispersive liquid–liquid microextraction (SIP-SS-DLLME) method was developed for the preconcentration of phenazopyridine. Protonated triethylamine bicarbonate is synthesized by the reaction of triethylamine and CO2 in the presence of water. This protonated switchable solvent (soluble in water) easily converted to triethylamine which is insoluble in water. Aliquat 336 was used as an ion-pair agent in this method, which results in the increase of the phenazopyridine extraction into the switchable solvent. Variables affecting the performance of extraction were studied and optimized. The relative standard deviation (RSD) was 3.1% for five repeated determinations containing 20 µg/L of phenazopyridine. The linear range of the method for microextraction and determination of phenazopyridine was found to be 5–180 µg/L with a detection limit of 0.88 µg/L. The presented method was applied successfully for the determination of phenazopyridine in pharmaceutical and biological samples.

Revisiting the Chemistry of Phosphinidene Sulfides

The reaction of triethylamine with the [4 + 2] cycloadducts of phosphole sulfides and 3-bromo-N-phenylmaleimide provides a convenient access to phosphinidene sulfides [RP═S]. These transient species are trapped by 2,3-dimethyl-1,3-butadiene to give the previously unknown trivalent [4 + 2] cycloadducts. One of these (R = Ph) has been characterized as its P-W(CO)5 complex by X-ray crystal structure analysis. With cyclopentadiene, the subsequent insertion of a second molecule of [RP═S] leads to a new type of bicyclic product containing a thiadiphospholane ring.

Nonaborane and Decaborane Cluster Anions Can Enhance the Ignition Delay in Hypergolic Ionic Liquids and Induce Hypergolicity in Molecular Solvents

The dissolution of nido-decaborane, B10H14, in ionic liquids that are hypergolic (fuels that spontaneously ignite upon contact with an appropriate oxidizer), 1-butyl-3-methylimidazolium dicyanamide, 1-methyl-4-amino-1,2,4-triazolium dicyanamide, and 1-allyl-3-methylimidazolium dicyanamide, led to the in situ generation of a nonaborane cluster anion, [B9H14](-), and reductions in ignition delays for the ionic liquids suggesting salts of borane anions could enhance hypergolic properties of ionic liquids. To explore these results, four salts based on [B10H13](-) and [B9H14](-), triethylammonium nido-decaborane, tetraethylammonium nido-decaborane, 1-ethyl-3-methylimidazolium arachno-nonaborane, and N-butyl-N-methyl-pyrrolidinium arachano-nonaborane were synthesized from nido-decaborane by reaction of triethylamine or tetraethylammonium hydroxide with nido-decaborane in the case of salts containing the decaborane anion or via metathesis reactions between sodium nonaborane (Na[B9H14]) and the corresponding organic chloride in the case of the salts containing the nonaborane anion. These borane cluster anion salts form stable solutions in some combustible polar aprotic solvents such as tetrahydrofuran and ethyl acetate and trigger hypergolic reactivity of these solutions. Solutions of these salts in polar protic solvents are not hypergolic.

The oxidation of the alpha-carbon of amines in hydrothermal condition: an alternative synthetic route of compounds containing amide bond

Here we report experimental evidence for the simple synthesis of N,N-diethylhydroxylamine and an amide bond formation reaction from oxidation of the alpha-carbon of tertiary amines by the reaction of triethylamine and hydrogen peroxide in hydrothermal conditions. It is proved that 120°C is a turning point: when the temperature is lower than that, the main product is N,N-diethylhydroxylamine as a result of a cope rearrangement reaction mechanism; on the contrary, the product is more complex and the main products are amides via a radical chain mechanism involving three steps: initiation, propagation, and oxidation, followed by decarbonylation and electrocyclization because the radical is easier to form under high temperature.

Direct Photoreduction and Ketone-Sensitized Reduction of Nitrospirobenzopyranindolines by Aliphatic Amines

The photoreduction of 6-nitrospiro[2H-1-benzopyran-2,2'-indoline] (N1) and two derivatives (N2 and N3) by diethylamine or triethylamine (TEA) in solution was studied by pulsed and steady-state photolysis. The quantum yield of coloration of the ring-closed Sp form, due to photoinduced ring opening, decreases in acetonitrile with increasing the TEA concentration. The main reason is reaction of TEA with the triplet-excited open merocyanine form. Quenching of this triplet state by amines is rather inefficient for N1-N3; the rate constant for triplet quenching by TEA is k(6) = (2-3) × 10(6) M(-1) s(-1). The secondary transient with an absorption maximum at 420 nm is ascribed to the radical anion. This and the corresponding α-aminoethyl radical subsequently undergo slow termination reactions, yielding a relatively stable product with a maximum at 420-450 nm, which is attributed to a ring-opened dihydromerocyanine (MH(-)). The mechanisms of the two subsequent reduction reactions are discussed. Using acetone as sensitizer the same dihydroproduct was obtained with the Sp form as acceptor, indicating a reaction sequence from photogenerated radicals via a ring-opened radical to MH(-)/MH(2). The effect of TEA concentration on the direct and ketone-sensitized reduction mechanisms was analyzed. Photoreduction by amines, due to competing triplet quenching, is strongly decreased on admission of oxygen.

Improved chromatographic performances of glycidyl methacrylate anion‐exchange monolith for fast nano‐ion exchange chromatography

An efficient and reproducible photopolymerized poly(glycidyl methacrylate-co-ethylene dimethacrylate) was synthesized in Teflon-coated fused-silica capillaries (100 μm id) and functionalized by reaction of triethylamine with reactive epoxy groups. We report here the successful transfer of a standard polymerization mixture optimized for the thermally initiated synthesis of glycidyl-based monolith to photo-induced polymerization. The monolith obtained after optimization of the photo-initiation conditions was characterized in reverse-phase chromatography evaluating its suitability in terms of efficiency, retention and hydrodynamic permeability. Reproducibility of the photo-induced procedure was satisfactory with RSD below 6% for retention and efficiency and slightly higher for hydrodynamic permeability (12%). The functionalized generic support was then used in nano-ion-exchange chromatography. Efficiencies up to 75,000 plates/m, ion-exchange capacity of 8 nano-equivalents/cm of monolithic column, with a combination of a satisfactory hydrodynamic permeability allowed to perform fast separations of five inorganic anions in <3 min maintaining baseline resolution. The efficiency of the monolith was not retention-dependent, demonstrating its wide range of possible applications for highly retained anions.

The catalytic action of triethylamine in the reaction of β-hydroxyethyl mercaptan with oxiranes

The formation of an interionically hydrogen-bonded complex during the reaction of triethylamine with β-hydroxyethyl mercaptan, the dissociation of the complex into ions, and the involvement of the mercaptide ion in epoxide ring opening are studied.

Triethylammonium halochromates/silica gel: an efficient reagent for oxidative coupling of thiols to disulfides

Triethylammonium halochromates, (C2H5)3NCrO3X, TEAXC (X = Cl, F) are easily synthesized by the reaction of triethylamine with a solution of chromium(VI) oxide in 6M hydrochloric acid, or a solution of chromium(VI) oxide in 40% hydrofluoric acid. These reagents are easily supported on common silica gel and can be used as heterogeneous oxidants. Triethylammonium halochromate(VI) is a versatile reagent for the effective and selective oxidation of organic substrates. Various aliphatic (cyclic and acyclic) and aromatic thiols are converted into the corresponding disulfides by treatment with triethylammonium fluorochromate(VI), (TEACC) or triethylammonium chlorochromate(VI), (TEAFC) supported on silica gel, in excellent yields and under mild reaction conditions.

Synthesis and transformations of triphenylpropargylphosphonium bromide

A method of the synthesis of triphenylpropargylphosphonium bromide is developed. Its isomerization and hydration in various solvents are studied, and reactions with secondary amines, triethylamine, and triphenylphosphine are carried out. It is established that secondary amines add to the intermediate allene isomer with subsequent migration of the formed double bond to the phosphorus atom. The reaction of triethylamine with triphenylpropargyl and triphenylethynyl bromides occurs similarly to alkaline hydrolysis involving attack of the amine on the phosphorus atom. Triphenylphosphine forms with triphenylpropargylphosphonium bromide a bis-salt with a terminal methylene group. Experimental evidence is obtained showing that for phosphoxazole derivatives to form from oximes derived from triphenyl(oxomethyl)phosphonium salts that latter should bear an aryl substituent at the keto group.

Metal–Organic Vapor Phase Epitaxy of GaN and InGaN Using Triethylamine with Ammonia as a Nitrogen Source

Metal–organic vapor phase epitaxy (MOVPE) of GaN and InGaN was investigated using a combination of triethylamine (TEA) and ammonia (NH3) as the nitrogen source. The reaction of TEA and NH3 in the gas phase was verified by quadrupole mass spectrometry. By using this nitrogen source, a GaN epitaxial layer was grown at 600 °C with a peak photoluminescence at 375 nm. An InxGa1-xN (x=0.6) eptaxial layer was also grown at 600 °C. The indium to gallium concentration ratio was verified by secondary ion-microprobe mass spectrometry (SIMS) and X-ray diffraction. It is confirmed that this is an effective nitride source for the efficient growth of GaN and InGaN.

Formation of polynuclear palladium complexes with the benzimidazole-2-thiolate anion

The reactions of palladium(II) salts with 2-mercaptobenzimidazole (HL) and its 5,6-difluorinated derivative (HLF) were investigated. In the presence of hydrochloric acid, PdCl2 and K2PdCl4 react with HL and HLF in the ethanol—water and acetonitrile—water systems to form the mono-nuclear dicationic complexes [Pd(HL)4]Cl2 (1) and [Pd(LF)4]Cl2 (2). In the absence of HCl, the reactions afford the tetranuclear complex Pd4[(L)2(μ3-S,N-(L))2(μS,N-(L))4] (3). The reaction of triethylamine with an ethanolic solution of 3 leads to degradation of 3 and the formation of the lantern-type dinuclear complex Pd2[(μ2-(L)4] (4), in which the palladium atoms are in the nonequivalent coordination environment, PdN4 and PdS4. The reaction of K2PdCl4 with HL or HLF in the THF—water or acetonitrile—water systems (for the reaction with HLF) in the presence of Et3N produces the lantern-type dinuclear complexes Pd2[(μS,N′-(L3))4] and Pd2[(μ-S,N′-(LF))4] (5), in which the metal atoms are in the equivalent coordination environment (cis-PdN2S2).

Dealkylation Reactions of Trialkylamines with 1,3,5-Trichloro-1,2,4,6-cyclothiatriazine: A Novel Route to Regiospecific Dialkylamino Substitution on Cyclocarbathiazines

Reaction of trialkylamines and diamines with 1,3,5-trichloro-1,2,4,6-cyclothiatriazine, (ClCN)2(ClSN), is found to result in the facile cleavage of a C−N bond of the tertiary amine and regiospecific substitution of the dialkylamino group on the carbon atoms of the heterocycle. Reaction of (ClCN)2(ClSN) with tetramethylmethylenediamine in diethyl ether at room temperature gives the thiatriazine with dimethylamino groups substituted on the ring carbon atoms, [(Me2N)CN]2(ClSN) (1). The reaction of triethylamine with (ClCN)2(ClSN) gives the diethylamino-substituted heterocycle [(Et2N)CN]2[S(O)NH] (2) which is partially saturated as a result of the hydrolysis of the S−Cl bond. The crystal structure of this compound shows it to be a dimer with hydrogen bonding interactions between the N−H and SO groups. Reaction of excess morpholine with (ClCN)2(ClSN) gives the trimorpholino-substituted compound [(OC4H8N)CN]2[(OC4H8N)SN] (3). The S−Cl bond of 1 has also been substituted with morpholine to give [(Me2N)CN]2[(OC4H8N)SN] (4). It is also observed that by using diethyl ether as a solvent, dealkylations can be brought about even at room temperature with these heterocycles.

Synthesis and insecticidal activity of O-aryl O-(1,2,2,2-tetrachloroethyl)phosphoramidothioates and their thiophosphoric hydrazides [1

O-Aryl O-(1,2,2,2-tetrachoroethyl)phos- phoramidothioates 3a–h and their thiophosphoric hydrazides 4a–e were synthesized by reactions of O-aryl O-(1,2,2,2-tetrachoroethyl)thiophosphorochloridates 2 with amines and hydrazines, respectively. Their structures were characterized by elemental analysis IR 1H NMR, 31P NMR, and MS. The O-aryl O-(1,2,2,2-tetrachloroethyl)thiophosphoric hydrazides 4a–d (R2=H) can be transformed into 1,3,4,2-oxadiazaphospholanes 5a–d by the reaction of triethylamine. The results of preliminary bioassays indicated that some of the title compounds have good insecticidal activities against nematodes (Meloidogyne spp.) and pea aphids. © 1999 John Wiley & Sons, Inc. Heteroatom Chem 10: 441–445, 1999

Structure and spectroscopic properties of 2,4-dichloro-1-diethylamino-3, 5-diphenyl-1,3-pentadien-5-one, the product of the unusual reaction of triethylamine with (dibenzoylmethanato)antimony tetrachloride

The crystal and molecular structures of the title compound have been established by the X-ray diffraction method. The molecule has a bent configuration with a dihedral angle between the double bond planes of 43.2°. The double bonds are localized and have lengths of 1.351(6) and 1.355(6) A. However vibrational and electronic spectroscopy indicate that the conjugation in the butadiene fragment is retained; this fragment is a conductor of the direct polar conjugation effect between the donor diethylamino group and the acceptor carbonyl group.

A Study of Effects of Temperature and Medium on Reaction of Triethylamine with Ethyl Bromide

The rate constants of reaction of triethylamine with ethyl bromide have been measured in 13 solvents at the temperatures of 293, 313, 333, and 373 K. The activation entropies in the individual solvents increase when going from nonpolar to dipolar aprotic and polar protic solvents, which is explained by dominant solvation of the basic triethylamine and by formation of highly ordered associates without solvent in the activated complex in nonpolar solvent media. No isokinetic relationship has been found between the activation entropy and activation enthalpy, which indicates different solvent effects on the two quantities. The activation enthalpy and entropy of the reaction investigated are close to those of the reaction of triethylamine with ethyl iodide. Three methods have been used to evaluate the effect of medium at all the temperatures, their success being decreased in the order: Pytela's method - Kamlet-Taft - Koppel-Palm. Irrespective of the temperature, all the methods indicate that the reaction is accelerated by the solvent polarity, the significance of other effects being reflected differently depending on the temperature and the correlation equation used. A complex evaluation involving also the interpretation of the entropy and enthalpy components by means of empiric solvent parameters has shown that the resulting Gibbs energy represents a superposition of different effects of solvents on the two thermodynamic quantities, the solvent effect upon the activation entropy being predominant at the higher temperatures.