Acid Dinitrile Research Articles

Dielectric parameters of polymers and monomers of the vinyl series in the microwave range

The production of polymeric materials is one of the fast-growing sectors in the chemical industry. Improving methods for synthesizing high-molecular compounds and studying their physicochemical characteristics are important tasks of synthetic chemistry. Radical polymerization is currently the main method for producing polymeric materials. Its advantages involve simplicity and low cost, along with the possibility of obtaining a wide range of polymeric materials. The results of measuring the dielectric parameters of various high-molecular compounds (polystyrene, polyvinyl chloride, polyvinyl acetate, polyvinyl alcohol, poly(glycidyl methacrylate)) in the frequency range of 100–200 GHz (refractive index and dielectric loss tangent tgδ) are presented. The compounds under study were both those synthesized by radical polymerization with the participation of the conventional initiator, i.e., azobisisobutyric acid dinitrile, and commercial products. The absorption capacity of polymers at room temperature was compared. Polymers with the highest and lowest absorption capacity were determined. The dependence of tgδ on frequency for all the polymers under study is linear, with absorption in the polymers increasing with frequency. Poly(glycidyl methacrylate) exhibits the highest absorption among the studied macromolecules with tgδ being equal to 0.043 at 200 GHz. The minimum tgδ value of 0.0068 was found for polystyrene. For the polymers under study, the refractive index value varies in the range from 1.09 to 1.39. In addition, dielectric properties of the original vinyl monomers (styrene, vinyl acetate, glycidyl methacrylate) were studied. The results are of interest when developing approaches to obtaining polymeric materials with specified characteristics based on vinyl monomers by the method of radical polymerization.

Pseudo Four-Component Synthesis of 5,6-Dihydroindolo[2,1-a]isoquinolines.

An easy synthesis of novel highly functionalized 5,6-dihydroindolo[2,1-a]isoquinolines was developed via a pseudo four-component domino reaction of 1-aroyl-3,4-dihydroisoquinolines, terminal α,β-ynones, and malononitrile. The selective formation of this biologically relevant heterocyclic core was achieved using a one-pot approach under microwave irradiation. The formation of the same skeleton through the reaction of 5,6-dihydropyrrolo[2,1-a]isoquinolines with malonic acid dinitrile supports the proposed mechanism, involving the intermediate product of the three-component reaction. Furthermore, the disproval of an alternative reaction pathway, which involved the dimerization of malononitrile followed by three-component transformation, was demonstrated. Introducing the malononitrile dimer as a CH acid resulted in the formation of a different pyrido[3',4':4,5]pyrrolo[2,1-a]isoquinoline core. Additionally, the synthesized 5,6-dihydroindolo[2,1-a]isoquinolines were examined for their photophysical properties, revealing their attractive luminescent characteristics.

New functional copolymers of 1-vinyl-1,2,4-triazole with allylamine

New water-soluble functional copolymers based on 1-vinyl-1,2,4-triazole and allylamine were synthesized under the action of free-radical initiation conditions and azobisisobutyric acid dinitrile. Сopolymers of various compositions with a molecular weight of 1287–30204 Da were obtained by varying reaction conditions. The structure, molecular weight and physicochemical properties of the copolymers were determined using elemental analysis, IR and NMR 1H-spectroscopy, gel permeation chromatography, potentiometric and turbidimetric titration, as well as dynamic light scattering and thermogravimetric analysis. It was established that the obtained copolymers, exhibiting the properties of high-resistance organic semiconductors, are characterized by a specific electrical conductivity of 10-13 – 10-14 S/cm and high resistance to thermal destruction (up to 260–280 °C). These copolymers are promising as stabilizing polymer matrices in the formation of biologically active water-soluble hybrid organic-inorganic nanocomposites.

Free Radical Hydrophosphorylation of Fluoroalkyl Vinyl Ethers: Synthesis of Fluoroalkyl Phosphonates

An effective method for the synthesis of dialkyl [2-(polyfluoroalkoxy)ethyl]phosphonates by free radical hydrophosphorylation of fluoroalkyl vinyl ethers with dialkyl (H)-phosphonates was developed. The reaction proceeds in the presence of catalytic amounts of azabisisobutyric acid dinitrile (AIBN) (150°C, 2 h, portionwise addition of AIBN) to afford the target fluoroalkyl phosphonates in up to 85% isolated yield.

Antiradical Activity of Porphyrins with a Diisobornylphenol Fragment at the Macrocycle Periphery.

This article focuses on the antiradical activity of a number of 2,6-diisobornylphenol-porphyrin conjugates with various spacers between the porphyrin and phenolic fragments in the model reaction of ethylbenzene oxidation initiated by azoisobutyric acid dinitrile. The study has shown that the electronic effects of the groups directly related to the 2,6-diisobornylphenol fragment exert the predominant influence both on the reactivity of the phenolic hydroxyl group in interaction with free radicals and on the antiradical activity of the molecule as a whole. The antiradical activity of the molecule is generally less affected by the nature of the substituents in the porphyrin macrocycle, mainly due to a change in the stoichiometric inhibition coefficient in the presence of relatively easily oxidizable groups. It was found that the length of the spacer between the porphyrin and phenolic fragments does not affect the antiradical activity of the conjugate.

Synthesis of 2-amino-5-(2-aryl-2-oxoethylidene)-4-oxo-1H-4,5-dihydrofuran-3-carboxylic acids derivatives by recyclization of 5-arylfuran-2,3-diones under the action of cyanoacetic acid derivatives

Recyclization of 5-arylfuran-2,3-diones under the action of ethyl cyanoacetate or of malonic acid dinitrile resulting in the corresponding esters or nitriles of 2-amino-5-(2-aryl-2-oxoethylidene)-4-oxo-1Н-4,5-dihydrofuran-3-carboxylic acids was investigated.

ChemInform Abstract: Broensted Acid‐Promoted Cascade Alkylation/Cyclization of Pyrroles with N,N‐Dimethylaminomethyleneglutaconic Acid Dinitrile: A Concise Route to Cyclopenta[b]pyrroles.

ChemInformVolume 47, Issue 9 Heterocyclic Compounds ChemInform Abstract: Broensted Acid-Promoted Cascade Alkylation/Cyclization of Pyrroles with N,N-Dimethylaminomethyleneglutaconic Acid Dinitrile: A Concise Route to Cyclopenta[b]pyrroles. Kaikai Wu, Kaikai Wu Dalian Inst. Chem. Phys., Chin. Acad. Sci., Dalian 116023, Peop. Rep. ChinaSearch for more papers by this authorPing Wu, Ping Wu Dalian Inst. Chem. Phys., Chin. Acad. Sci., Dalian 116023, Peop. Rep. ChinaSearch for more papers by this authorJiping Chen, Jiping Chen Dalian Inst. Chem. Phys., Chin. Acad. Sci., Dalian 116023, Peop. Rep. ChinaSearch for more papers by this authorChenglin Sun, Chenglin Sun Dalian Inst. Chem. Phys., Chin. Acad. Sci., Dalian 116023, Peop. Rep. ChinaSearch for more papers by this authorZhengkun Yu, Zhengkun Yu Dalian Inst. Chem. Phys., Chin. Acad. Sci., Dalian 116023, Peop. Rep. ChinaSearch for more papers by this author Kaikai Wu, Kaikai Wu Dalian Inst. Chem. Phys., Chin. Acad. Sci., Dalian 116023, Peop. Rep. ChinaSearch for more papers by this authorPing Wu, Ping Wu Dalian Inst. Chem. Phys., Chin. Acad. Sci., Dalian 116023, Peop. Rep. ChinaSearch for more papers by this authorJiping Chen, Jiping Chen Dalian Inst. Chem. Phys., Chin. Acad. Sci., Dalian 116023, Peop. Rep. ChinaSearch for more papers by this authorChenglin Sun, Chenglin Sun Dalian Inst. Chem. Phys., Chin. Acad. Sci., Dalian 116023, Peop. Rep. ChinaSearch for more papers by this authorZhengkun Yu, Zhengkun Yu Dalian Inst. Chem. Phys., Chin. Acad. Sci., Dalian 116023, Peop. Rep. ChinaSearch for more papers by this author First published: 11 February 2016 https://doi.org/10.1002/chin.201609149Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume47, Issue9February, 2016 RelatedInformation

Copolymerization of Peroxy Derivatives of Dioxydiphenylpropane Diglycidyl Ether Monomethacrylate with Styrene

The copolymerization reaction of peroxy derivatives of dioxydiphenylpropane diglycidyl ether monomethacrylate with styrene has been studied at 333 K in the medium of toluene using azo-bis-isobutyric acid dinitrile as an initiator at different molar ratio of the initial monomers. The reaction rates have been determined and copolymerization constants have been calculated. The structure of the synthesized copolymers was confirmed by chemical and IR-spectroscopic analyses.

Brønsted Acid‐Promoted Cascade Alkylation/Cyclization of Pyrroles with N,N‐Dimethylaminomethyleneglutaconic Acid Dinitrile: A Concise Route to Cyclopenta[b]pyrroles

AbstractA Brønsted acid (p‐TsOH⋅H2O) promoted alkylation/cyclization cascade reaction of pyrroles with N,N‐dimethylaminomethyleneglutaconic acid dinitrile was efficiently realized to afford functionalized cyclopenta[b]pyrroles with excellent diastereoselectivity. Deamination of the corresponding ammonium salts of the cyclopenta[b]pyrroles with methyl iodide led to dihydrocyclopenta[c]pyrroles. The cascade reaction pathway was confirmed by isolation and transformation of the reaction intermediate, i.e., the 2‐alkylated pyrrole.magnified image

A sterically hindered cobalt o-iminobenzosemiquinone complex in the polymerization of vinyl monomers

The influence of bis[4,6-di-tert-butyl-N-(2,6-dimethylphenyl)-o-iminobenzosemiquinonato]cobalt (II) on the radical polymerization of methyl methacrylate and styrene under the conditions of radical initiation by azo-bis-isobutyric acid dinitrile in the temperature range 70–90°C has been studied. The use of the cobalt complex containing redox-oxidized ligands leads to the suppression of autoacceleration of the polymerization of methyl methacrylate and to a linear increase in the molecular masses of the polymers with conversion. In the case of styrene polymerization, the control over the kinetics of the process and molecular weight characteristics of the polymers synthesized in the presence of the cobalt iminobenzosemiquinone complex is less pronounced.

Heterophase polymerization of vinylene carbonate in octane

Results of the study of heterophase polymerization of vinylene carbonate induced by azo-bis-isobutyric acid dinitrile are analyzed. The mechanism of reaction and the polymerization kinetics are considered; the molecular characteristics of polyvinylene carbonate are determined.

ChemInform Abstract: Synthesis of Angular Trioxacyclopentaphenanthrenes by the Reaction of Substituted 2‐Furanones with Malonic Acid Dinitrile.

ChemInform Abstract: Synthesis of Angular Trioxacyclopentaphenanthrenes by the Reaction of Substituted 2‐Furanones with Malonic Acid Dinitrile.

Synthesis of angular trioxacyclo-pentaphenanthrenes by the reaction of substituted 2-furanones with malonic acid dinitrile

Synthesis of angular trioxacyclo-pentaphenanthrenes by the reaction of substituted 2-furanones with malonic acid dinitrile

Chemiluminescence determination of o-chlorobenzylidenemalonic acid dinitrile in extracts

A chemiluminescence method was developed for determining o-chlorobenzylidenemalonic acid dinitrile (o-CBMA DN) in extracts. The method is based on chemiluminescence developed in a strong alkaline solution upon the interaction between 3-aminophthalic hydrazide (luminol) with the superoxide radical formed in the reaction of atmospheric oxygen activated by hemin with the products of the alkaline hydrolysis of o-chlorobenzylidenemalonic acid dinitrile and with the products of their condensation with p-nitrobenzaldehyde. The luminescence intensity of luminol was proportional to the concentration of o-CBMA DN in the range 1 × 10−6−1 × 10−1 mg/mL. The determination limit for o-CBMA DN was (1 ± 0.3) × 10−6 mg/mL (p = 95%, n = 5, RSD = 29%) at 293 K.

Features of the Polymerisation Kinetics of Methyl Methacrylate in the Presence of Initiators of Different Structure

The thermographic method was used to study the polymerisation kinetics of methyl methacrylate (MMA) at 60°C in the presence of initiators: dicyclohexylperoxy dicarbonate (CPC), azoisobutyric acid dinitrile (AIAD), benzoyl peroxide (BP), and lauryl peroxide (LP). In the region of initial conversions, the mechanism of chain growth limitation is bimolecular, and the order of the reaction with respect to the initiator is 0.5. In the region of the maximum polymerisation rate, the order of the reaction with respect to the initiator is greater than 0.5 and varies according to the initiator concentration. The mechanism of chain growth limitation at extensive conversions is monomolecular. Additional initiation occurs through degradation of the polymer, governed by the formation of stresses during polymerisation. The observed differences in the polymerisation kinetics in the MMA–CPC system are connected with the redistribution of initiator in regions with inhomogeneous concentrations of monomer and polymer.

Radical copolymerization of N-vinylformamide with unsaturated carboxylic acids

Radical precipitative copolymerization of N-vinylformamide with acrylic and methacrylic acids in isopropanol at 60°C, with azobisisobutyric acid dinitrile as initiator, was studied. The conditional values of the relative reactivities were found: r1 = 0.068 ± 0.008 and r2 = 1.638 ± 0.025 for the N-vinylformamide-methacrylic acid copolymer and r1 = 0.15 ± 0.03 and r2 = 0.19 ± 0.09 for the N-vinylformamide-acrylic acid copolymer.

Cloning of a nitrilase gene from the cyanobacterium Synechocystis sp. strain PCC6803 and heterologous expression and characterization of the encoded protein.

The gene encoding a putative nitrilase was identified in the genome sequence of the photosynthetic cyanobacterium Synechocystis sp. strain PCC6803. The gene was amplified by PCR and cloned into an expression vector. The encoded protein was heterologously expressed in the native form and as a His-tagged protein in Escherichia coli, and the recombinant strains were shown to convert benzonitrile to benzoate. The active enzyme was purified to homogeneity and shown by gel filtration to consist probably of 10 subunits. The purified nitrilase converted various aromatic and aliphatic nitriles. The highest enzyme activity was observed with fumarodinitrile, but also some rather hydrophobic aromatic (e.g., naphthalenecarbonitrile), heterocyclic (e.g., indole-3-acetonitrile), or long-chain aliphatic (di-)nitriles (e.g., octanoic acid dinitrile) were converted with higher specific activities than benzonitrile. From aliphatic dinitriles with less than six carbon atoms only 1 mol of ammonia was released per mol of dinitrile, and thus presumably the corresponding cyanocarboxylic acids formed. The purified enzyme was active in the presence of a wide range of organic solvents and the turnover rates of dodecanoic acid nitrile and naphthalenecarbonitrile were increased in the presence of water-soluble and water-immiscible organic solvents.

SYNTHESIS AND NEUROTROPIC ACTIVITY OF PYRROLO(2,3-c)PYRAN(THIOPYRAN, PYRIDINE) AND PYRANO(THIOPYRANO, PYRIDO)(4,3:4,5)PYRROLO- (1,2-b)asym-TRIAZINE DERIVATIVES

In continuation of our previous investigations devoted to the synthesis of condensed pyrroles [1 – 3], we have developed a method for the synthesis of pyrrolo[2,3-c]pyran(thiopyran, pyridine) derivatives proceeding from 2,2-dimethyl-4-tetrahydropyranylidenemalonic acid dinitrile (Ia) and its thiopyran and pyridine analogs (Ib and Ic, respectively) [4]. The interaction of compounds Ia – Ic with substituted phenyl(furyl)diazomethylketones led to derivatives of pyrrolo[2,3-c]pyran(thiopyran, pyridine) derivatives (IIa – IIi). By treating compounds IIa – IIi with an ethanol solution of potassium hydroxide, we obtained a series of derivatives representing a new heterocyclic system: pyrano(thiopyrano, pyrido)[4 ,3 :4, 5]pyrrolo[1,2-b]asym-triazines (IIIa – IIIi). A special method developed for the synthesis of compounds IIIa – IIIi is based on the reactions of compounds Ia – Ic with diazomethyl ketones on heating to 70°C. Using this procedure, compounds IIIa – IIIi are obtained without isolating intermediate pyrroles IIa – IIi. I: X = O (a), S (b), N-CH3 (c); I, III: X = O, R = C6H5 (a); X = O, R = o-C6H4Cl (b); X = O, R = p-C6H4Cl (c); X = O, R = p-C6H4NO2 (d); X = O, R = p-C6H4CH3 (e); X = O, R = m-C6H4NO2 (f); X = O, R = (g), X = S, R = C6H5 (h);

Determination of copper by its catalytic effect on the oxidation of hydroquinone by hydrogen peroxide on supports

The reaction of oxidation of hydroquinone by hydrogen peroxide catalyzed by copper(II) in the presence of 2,2’-dipyridyl is activated by hexamethylenediamino groups that are bonded to the surface of filter paper; additional activating effect is produced by 2,2′-dipyridyl. The introduction of malonic acid dinitrile into the indicator reaction improves the sensitivity of the determination of copper and the contrast of the reaction in solution because of the formation of a blue product. Differently colored compounds are formed on a paper support at different concentrations of copper, which makes it possible to visually distinguish the quantities of copper that differ by an order of magnitude in the range 1 × 10-5-0.5 µg. Quantitative detection is possible in the range 5 × 10-6-0.1 µg (cmin = 3 × 10-6 µg). The concentration of copper (0.2-1.5 µg/mL) is determined in blood serum; the consumption of the sample per one determination is 3 µL

Synthesis of low band gap polymers - a challenge for organic chemists

Stable intrinsic semiconductors, which exhibit conductivities of 0.1 S/cm without any doping process can be easily prepared by using our “shish-kebab” approach. Hereby stacked transition metal macrocycles [MacM(L)] n with M e.g. Fe, Ru, Os and Mac = phthalocyanine (Pc) or 2,3-naphthalocyanine (2,3-Nc) are used. The bridging ligands (L) are special heteroaromatic systems, e.g. s-tetrazine (tz), substituted tetrazines, triazine (tri), substituted trizines, but also special organic dinitriles, e.g. tetrafluoroterephthalic acid dinitrile, fumarodinitrile, dicyanoacetylene, and dicyane. We report about the preparation and the characterization of the corresponding transition metal complexes [MacM(L)] n. The intrinsic conductivities of all these compounds are a result of the low oxidation potential of the bridging ligands and due to the low lying LUMO in the corresponding bridged systems [MacM(L)] n. The electrical and physical properties, especially the UV- and Möβbauer spectra (for the corresponding iron compounds) for the bridged macrocyclic metal complexes are discussed in respect to the intrinsic semiconducting properties of these compounds.