Nitrogen-containing Organic Bases Research Articles

Kinetically Controlled Acid–Base Interaction of Tetra-4-chloro-tetra-5(5-methyl-2-isopropylphenoxy)phthalocyanine with Nitrogen-Containing Organic Bases

Kinetically Controlled Acid–Base Interaction of Tetra-4-chloro-tetra-5(5-methyl-2-isopropylphenoxy)phthalocyanine with Nitrogen-Containing Organic Bases

Destruction of Octa(4-tert-butylphenyl)tetrapyrazinoporphyrazine Under the Influence of Nitrogen-Containing Organic Bases in Dimethylsulfoxide

Destruction of Octa(4-tert-butylphenyl)tetrapyrazinoporphyrazine Under the Influence of Nitrogen-Containing Organic Bases in Dimethylsulfoxide

Destruction of Octa(4-tert-butylphenyl)tetrapyrazinoporphyrazine Under the Influence of Nitrogen-Containing Organic Bases in Dimethylsulfoxide

A study is performed of the state of octa(4-tert-butylphenyl)tetrapyrazinoporphyrazine in dimethyl sulfoxide. It is found that the acid–base interaction of partner molecules creates a time-stable complex with proton transfer. It is shown that adding morpholine, piperidine, n-butylamine, and diethylamine to dimethyl sulfoxide results in destruction of this complex, in contrast to adding pyridine, 2-methylpyridine, tert-butylamine, or tri-n-butylamine. The effect the proton-acceptor ability and the spatial structure of the base have on the decomposition of the tetrapyrazinoporphyrazine macrocycle is considered.

IONIZATION OF ETHANOLAMINES IN WATER- ORGANIC MEDIA

In this paper, the ionization constants (pKa) of some nitrogen-containing organic bases (monoethanolamine, diethanolamine and triethanolamine) in water-ethanol, water-acetone and water-acetonitrile solutions at various concentrations of organic solvent in the studied systems have been determined by the potentiometric titration method. It was found that the values of pKa of monoethanolamine, diethanolamine and triethanolamine in aqueous-organic solutions naturally decreases with increasing concentration of organic solvent in the system. It was shown that their nature and the physico-chemical properties of the medium are significantly influenced by the nature and degree of change in the electron donor ability of the studied nitrogen-containing organic bases. It should be noted that for the studied nitrogen-containing organic bases (monoethanolamine, diethanolamine and triethanolamine), when passing from an aqueous medium to an organic one (ethanol or acetone or acetonitrile), the pKa values naturally decrease with an increase in the content of the organic solvent in the system. In general, in the transition from an aqueous medium to an organic one (ethanol or acetone or acetonitrile), a change in pKa can reach 1.73 units. It was established that the dependence of the values of pKa of nitrogen-containing organic bases which were determinate via potentiometric titration method on the inverse of the dielectric constant of water-ethanol and water-acetone or water-acetonitrile solutions tends to be linear, consistent with Izmailov’s theory. Thus, we can conclude that the change in the ratio of the mixed solvent components and, as a result, in general, dielectric permeability of the medium does not lead to a significant change in the solvation characteristics of the studied nitrogen-containing organic bases.

Facile and Sensitive Detection of Nitrogen-Containing Organic Bases with Near Infrared C-Dots Derived Assays.

In this article, we have designed both colorimetric (including solution and test paper type) and spectral sensors (including UV-vis and PL type) for the quick and sensitive detection of general nitrogen-containing organic bases (NCOBs); the limit of detection could reach as low as 0.50 nM. NCOBs included 11 examples, covering aliphatic and aromatic amines, five- and six-membered heterocyclics, fused-ring heterocyclics, amino acids, and antibiotics. Furthermore, the assays demonstrated high reliability in sensing NCOBs and excellent ability to distinguish NCOBs from oxygen and sulfur containing organics. The assays developed could find important applications for the detection of NCOBs in the fields of biomedicine, chemistry, and agriculture.

EFFECT OF MODIFYING ADDITIVES ON CHEMOSORPTION OF SULFUR (IV) OXIDE BY FIBROUS MATERIAL IMPREGNATED WITH POLYETHYLENEPOLYAMINE

The principal possibility of increasing of the absorption capacity of impregnated fibrous chemisorbents (IFCS) acid gases based on nitrogen-containing organic bases by introducing into impregnating solutions of some additives such as sodium chloride, potassium iodide, ethylenediaminetetraacetic acid disodium salt (EDTA), glycine, sodium and potassium carbonates was investigated. Under static conditions using a vacuum sorption unit with McBen-Bakr quartz spring scales the hydrophilicity of fibrous chemisorbents of acid gases based on polyester synthetic fibers impregnated with polyethylenepolyamine containing as modifiers of potassium, such as potassium modifiers, such as promoters sodium and potassium carbonates, glycine and the disodium salt of ethylenediaminetetraacetic acid was studied. It is shown that the introduction of these additives leads to a sharp increase in the hydrophilicity of the samples, which creates the preconditions for further more efficient chemisorption of sulfur(IV) oxide. Within the framework of the Brunauer-Emmett-Teller theory of polymolecular sorption, water vapor sorption isotherms are analyzed, the values of the monolayer capacity and the values of the sorption heat of water molecules in the first layer are determined. Under static and dynamic conditions, chemisorption of sulfur oxide (IV) by dry and moistened samples of chemisorbents was studied. It is established that the process of SO2 chemisorption can occur only in the presence of «free» water formed after the formation of the monolayer. It is shown that the introduction of hydrophilized additives leads to a significant increase in the absorption capacity of sulfur(IV) oxide in both static and dynamic conditions. The obtained results are planned to use in the development of theoretical bases for the creation of functional sorption filtering materials for respiratory purposes.

IONIZATION OF SOME NITROGEN-CONTAINING ORGANIC BASES IN WATER-ETHANOL AND WATER-ACETONE MEDIA

In this paper, the ionization constants (pKa) of some nitrogen-containing organic bases (morfoline, piperidine and benzylamine) in water-ethanol and water-acetone media at various concentrations of organic solvent in the system has been determined by the potentiometric titration method. It was established that the value of pKa of nitrogen-containing organic bases in aqueous-organic media naturally decreases with increasing content of organic solvent in the system. It was shown that their nature (aromatic or heterocyclic) and the physico-chemical properties of the medium are significantly influenced by the nature and degree of change in the electron donor ability of the nitrogen-containing organic bases studied It should be noted that for the studied nitrogen-containing organic bases (morfoline, piperidine and benzylamine), when passing from an aqueous medium to an organic one (ethanol or acetone), the pKa values naturally decrease with an increase in the content of the organic solvent in the system. In general, in the transition from an aqueous medium to an organic one (ethanol or acetone), a change in pKa can reach 2.43 units. It was established that the dependence of the values of pKa of nitrogen-containing organic bases which were determinate via potentiometric titration method on the inverse of the dielectric constant of water-ethanol and water-acetone solutions tends to be linear, consistent with Izmailov’s theory. Thus, we can conclude that the change in the ratio of the mixed solvent components and, as a result, in general, dielectric permeability of the medium does not lead to a significant change in the solvation characteristics of the nitrogen-containing organic bases studied.

THE ELECTRON DONATING PROPERTIES OF NITROGENCONTAINING ORGANIC BASES IN WATER-ETHANOL AND WATER-ACETONE SOLUTIONS

In this paper, the dissociation constants (pKa) of some nitrogen-containing organic bases (aniline, pyridine and octylamine) in water-ethanol and water-acetone media at various concentrations of organic solvent in the system has been determined by the potentiometric titration method. It was established that the value of pKa of nitrogen-containing organic bases in aqueous-organic media naturally decreases with increasing content of organic solvent in the system. It was shown that their nature (aliphatic, aromatic, heterocyclic) and the physicochemical properties of the medium are significantly influenced by the nature and degree of change in the electron donor ability of the nitrogen-containing organic bases studied. It was noted that for aniline in water-ethanol solutions in the transition from water to an organic solvent, the value of pKa does not change much (ΔpKa = 0,9), while for pyridine and octylamine these changes are significant, and the values of ΔpKa are 2,9 and 1,7, respectively, which can be explained by the specific solvation of the aniline amino group with ethanol. In the case of water-acetone solutions, the behavior of the nitrogen-containing organic bases was studied generally similar, and the values of ΔpKa are within the range of 1,7-2,6. It was established that the dependence of the values of pKa of nitrogen-containing organic bases on the inverse of the dielectric constant of water-ethanol and water-acetone solutions tends to be linear, consistent with Izmailov’s theory. Thus, we can conclude that the change in the ratio of the mixed solvent components and, as a result, in general, dielectric permeability of the medium does not lead to a significant change in the solvation characteristics of the nitrogencontaining organic bases studied.

Organic bases, carbon dioxide and naphthenic acids interactions. Effect on the stability of petroleum crude oil in water emulsions

Understanding the mechanisms that lead to the formation of petroleum crude oil in water emulsion is fundamental for the development of sustainable exploitation procedures and efficient oil spills remediation technologies. In this study we surveyed the effectiveness of different nitrogen-containing organic bases in promoting emulsification through the interaction with the naphthenic acid fraction present in crude oil. It was found that bulky secondary amines were the most effective, able to stabilize the emulsion at 10 wt% of oil content for more than 20 min, and the emulsion at 40 wt% for more than 5 h. Interfacial tension measurements indicated that the interaction was effective even when naphtenic acids were dosed at very low levels (total acid number lass than 0.3). It was also observed that a successive addition of carbon dioxide to the system readily induced the breaking of the emulsion, probably by affecting the equilibrium involved in the formation of the naphthenates stabilizing species. In the light of these findings, we tested polyethylene glycols bearing a terminal amino moiety as a new class of CO2 responsive emulsifiers suitable for the petroleum industry.

Structural and anti-oxidant properties of guanidinium pyrazole-3,5-dicarboxylates

Multicomponent crystals (either salts or co-crystals) of pyrazole-3,5-dicarboxylic acid (H3pzdc) with the nitrogen-containing organic bases guanidine (Gun), aminoguanidine (Agun), diaminoguanidine (Dagun) and triaminoguanidine (Tagun) have been synthesized and characterized by IR spectroscopy, TG-DTA, and single-crystal X-ray diffraction.

Reactions of P(III) chlorides with aldehydes: I. Synthesis of primary intermediates of the reactions of aliphatic aldehydes with P(III) chlorides possessing electrophilic properties

An approach to investigation of reactions of electrophilic P(III) chlorides with aliphatic aldehydes is developed. Its essence is the removal of HCl impurity from chloride and catalytic blocking of electrophilic center of the carbonyl group. For these purposes nitrogen-containing organic bases and alkyl vinyl ethers are used. Three types of primary intermediates with the nearest P(III) environment POCl2, O2PCl, and O3P are synthesized. It is established that the stability of intermediates increases with the growing acceptor properties of substituents at P(III) and donor properties of the aldehyde fragment.

Binary system organic base-anode in the oxidative activation of hydrogen sulfide

Initiation of the reaction between hydrogen sulfide and aliphatic, aromatic, and heteroaromatic hydrocarbons in acetonitrile using the binary system organic base-anode is described. The reaction of hydrogen sulfide with nitrogen-containing organic bases is studied by means of cyclic voltammetry. The reaction of hydrogen sulfide with triethylamine leads to the formation of thiolate anion. The next step o reaction is electrochemical oxidation of the thiolate anion that to lead thiyl radical formation in situ thiyl radicals. In the presence of binary system on the basis of hydrogen sulfide aliphatic, aromatic, and heteroaromatic thiols and sulfides are formed at room temperature.

Sputtering source of cluster ions and surface-ionization source of polyatomic ions of organic compounds

Development and characterization of sputtering sources of negative cluster and molecular ions of Aum- (m=1–9), Sim- (m=1–6), SimOn- (m=1–5, n=1–11), Cm- (m=1–12), NimCln- (m=1–2, n=0–3) and surface-ionization (SI) sources of polyatomic positively charged ions of organic compounds are described. The currents of the molecular and cluster ions obtained after separation were very stable and reach several nA for the sputtering source and from 10−10 up to10−7A/sm2 for the SI source. A possibility of using the high selectivity of SI and the high efficiency of SI of nitrogen-containing organic bases to produce practically composition-homogeneous effective beams of polyatomic positively charged ions is demonstrated in this work.

Lipophilic ionic additive for controlling the selectivity of ion-selective electrodes reversible to cations of nitrogen-containing organic bases

The effect of a lipophilic ionic additive, a tetradecylammonium salt of a liquid ion exchanger, on the selectivity of ion-selective electrodes (ISEs) for cations of nitrogen-containing organic bases was studied. Additive-containing ISEs exhibited a higher selectivity for cations of primary to tertiary amines as compared to that for quaternary ammonium cations. A maximum change in selectivity (up to more than two orders of magnitude) due to the introduction of tetradecylammonium was observed for membranes containing dinonyladipate as a plasticizer and tris(nonyloxy)benzene sulfonic acid as an ion exchanger. In this case, the introduction of lipophilic ionic additive may lead to the reversal of the selectivity series. The effect of the lipophilic ionic additive on the selectivity of ISEs with membranes plasticized with o-nitrophenyl octyl ether decreased approximately by an order of magnitude. The selectivity of ISEs with the membranes containing tetrakis(4-chlorophenyl) borate as a cation exchanger was virtually independent of the presence of lipophilic ionic additives. The results obtained were explained by the peculiarities of ion-pair formation in the membrane.

Kinetics of Formation of Octa(p-Bromophenyl)tetraazaporphine Complexes with N-Bases in Benzene-Dimethyl Sulfoxide System

The acid-base interaction of octa(p-bromophenyl)tetraazaporphine with nitrogen-containing organic bases in benzene-DMSO system is studied. The structures of the proton-transfer complexes formed in the reaction are suggested. The reaction rate, activation parameters, and mechanism of intermolecular transfer of protons of the NH groups of octa(p-bromophenyl)tetraazaporphine to a base were shown to be determined by the nature of the proton-acceptor molecules. The dielectric permeability of a binary solvent was found to significantly affect the kinetic parameters of the process.

The Maximum Hardness Principle and the Composition of Zn(II) and Cd(II) Tetrafluoroborate Complexes with Nitrogen-Containing Organic Bases

The hardness/softness parameters of the central complexing ion, the donor nitrogen atom of the ligand, and the coordination bond were calculated for zinc and cadmium tetrafluoroborate complexes with nitrogen-containing organic bases of various composition (both experimentally determined and hypothetical). On the basis of the quantitative estimate of the hard/soft characteristics of the whole series of the coordination compounds considered, it was found that the hardest parameters are inherent in the complexes isolated in a pure state by a preparative method.

A Thermal-Desorption Surface-Ionization Indicator of Narcotics and Other Drug Preparations

The results of the development of a new method and instrument for determining trace narcotics and other abused drugs in extracts of biological samples (urine, blood, and postmortem specimens) from users of the above substances are reported. The method is based on the unique selectivity (up to ∼105–108 with respect to organic solvents or up to ∼1010 with respect to simple gases) and high efficiency of the surface ionization of nitrogen-containing organic bases and on the use of the temperature-programmed evaporation of sample molecules from an evaporator to the surface of an ionizer (emitter). This method provides not only the detection of trace substances (for example, opiates and amitriptyline at a picogram level) but also their identification based on the most probable evaporation temperature.

On the Problem of the Tetrafluoroborate Ion State in Complexes with Nitrogen-Containing Organic Bases

Using a number of Cu(II), Zn(II), and Cd(II) tetrafluoroborate complexes with nitrogen-containing organic bases as examples, the possible existence of two states of the BF4– ion, namely, the "half-coordination" and counter-ion states, was studied. It was found that in [ML2(BF4)2] complexes with strong organic bases (L), the "half-coordination" of the anion exists. As the electron-donating ability of the ligand increases, the interaction between the tetrafluoroborate ion and the metal atom becomes more efficient.

Extraction of Zn(II) and Cd(II) with diphenylcarbazone in presence of nitrogen-containing organic bases

The extraction of Zn(II) and Cd(II) with diphenylcarbazone in benzene in the presence of nitrogen-containing organic bases has been studied. The effect of various variables such as pH, and concentration of diphenylcarbazone and of base on the extraction has been investigated. The extracting species are [Zn(HD) 2·B·H 2O] and [Cd(HD) 2·2B]. The relative effectiveness of the bases as synergists is in the order β-picoline > pyridine > quinoline. The extraction constants for Cd(II) are higher than those of Zn(II).

Extraction of Zn(II) and Cd(II) with anthranilic acid in the presence of nitrogen-containing organic bases

Zinc and cadmium anthranilates do not extract into non-polar solvents alone in the pH range 4.5–6.5. But their extraction is synergistically enhanced in presence of N bases, apparently by displacement of coordinated water. The synergistic effect varies with the bases in the order β-picoline > pyridine > quinoline. The values of extraction constants suggest that cadmium forms more stable complexes than zinc.