Polyfunctional Carboxylic Acids Research Articles

Membrane transport of polyfunctional alkyl (N-alkyl-N,N-dioctylammoniomethyl)phosphonates

The membrane transport properties of phosphorylated betaines in relation to mono- and polyfunctional carboxylic acids were studied. The structure of transferred H-complexes was discussed; using IR spectroscopy, the main coordination centers of carriers were revealed. Using the method of quantum chemical calculations, the relationship between the amount of substrate flux, their lipophilicity and the structure of the resulting H-complexes was shown.

Specific Features of the Reactions of Pentaphenylantimony with Polyfunctional Heterocyclic Carboxylic Acids

Pyridine-2,6- and 2,5-dicarboxylic acids have acted as bifunctional compounds in the reactions with pentaphenylantimony, forming bis(tetraphenylantimony)pyridine-2,6- and 2,5-dicarboxylate, respectively. The interaction of pentaphenylantimony with 2-[(6-hydroxy-5-nitroso-4(3H)-oxopyrimidin-2-yl)sulfanyl]acetic acid involving carboxyl and hydroxyl groups in the pyrimidine ring has afforded 2-{[5-nitroso-4(3H)-oxo-6-(tetraphenylstiboxy)pyrimidin-2-yl]sulfanyl}tetraphenylantimony acetate. The structural features of the synthesized compounds have been established by means of X-ray diffraction analysis.

Synthesis and Transport and Ionophoric Properties of α,ω-Diphosphorylated Azapodands: XII. Membrane Transport of Organic Acids by Diphosphorylated Diamines and Diazapodands

Membrane transport of mono- and polyfunctional carboxylic acids mediated by phosphorylated diamines has been studied. The structure of complexes transferred through the membrane has been discussed; in some cases, a relation has been found between the efficiency of membrane transport of organic acid substrates and the structure of membrane carriers and their complexes with the acids. A correlation between the transmembrane flow and shift of some characteristic IR absorption bands (as well as change of their intensity) of the substrate–carrier complexes in comparison to the corresponding substrates and carriers has been estimated.

Synthesis, Transport, and Ionophoric Properties of α,ω-Biphosphorylated Azapodands: X. Membrane Transport of Organic Acids by Phosphorylated α,ω-Diazapodands

The membrane transport properties of novel phosphorylated azapodands with respect to mono- and polyfunctional carboxylic acids were studied. The structures of the transported Н-complexes are discussed, the complexing centers in the carriers are considered, and the correlations between the structure and transmembrane transport efficiency of the acid substrates are demonstrated.

The Novelties Producing by Ozonolysis of Petroleum High-Molecular Components

Specific properties of ozonolysis products of high-molecular heteroatomic compounds (resins and asphaltenes) from crude petroleums and natural bitumens are described. It is shown that polyfunctional carboxylic acids or their salts obtaining by alkaline hydrolysis of ozonization products of heavy petroleum<br />stocks permits to produce manifold useful novelties such as high-effective demulsifiers for petroleum dehydration process instead of expensive synthetic demulsifying reagents; water-soluble organic astringents suitable for chemical land-reclamation or to prepare moulding mixtures at the foundries; oily or emulsion<br />lubricating coolants for metal-working tools; stimulators of soil microorganisms activity and plant growth. The new chemical products of petroleum origin are not inferior to the best synthetic reagents for the same destinations but differ from the lasts advantageously on account of the simplicity of their production technology and low cost. The optimal expenses and other principal technological parameters were established both for raw material ozonization, following alkaline treatment and final product isolation stages of the production process for each new reagent described. By means of numerous laboratory experiments and field tests performed with seeds, bulbs and grafts of different agricultural plants and with ozonolysis products produced from the resinous components of different crude petroleums it was proved that high biological activity is characteristic only of the substances obtained from high-molecular compounds from low-sulfur naphthenic crude petroleums and natural bitumens occurring, as a rule, at small burial depths. These ozonolysis products are very effective stimulants for the different plants growth, suitable for a treatment of different forms of planting materials and providing significant acceleration of early growth stages, the reduction of vegetation and ripening periods, and the increase of total productivity of agricultural plants.

Synthesis of new lipophilic phosphine oxide derivatives of natural amino acids and their membrane transport properties toward carboxylic acids

One-pot procedures were developed for the synthesis of lipophilic N-(dialkylphosphorylmethyl) derivatives of natural amino acids with high yields from dioctyl- or didecylphosphine oxide, formaldehyde, and amino acid in the presence of amino acid hydrochloride. The reactions with some amino acids were also effective under catalysis by crown ether. The structure of the isolated N-(dialkylphosphorylmethyl) and N,N-bis(dialkylphosphorylmethyl)amino acids was determined on the basis of 1H, 13C, and 31P NMR and mass spectra; the structure of (S)-N-[(dicyclohexylphosphoryl)methyl]-α-alanine was proved by X-ray analysis, and intermolecular association of its molecules in crystal was characterized. Membrane transport properties of the new phosphorylated amino acids with respect to polyfunctional carboxylic acids were studied, and factors responsible for the efficiency and selectivity of membrane transport of acid substrates were estimated. Selective extraction of glutaric acid through a liquid membrane containing N,N-bis[(dioctylphosphoryl)methyl]-β-alanine was revealed.

Matrixes in UV-MALDI mass spectrometry – crystals of organic salts versus co-crystals of neutral polyfunctional carboxylic acids

Despite enormous instrumental mass spectrometric (MS) developments, providing sufficient advantages towards highly selective and sensitive analytical protocols, including those related to different ionization techniques, the presented paper aimed to study the ionization UV-MALDI-MS process and to describe the chemical aspects and essential role of the types of the matrixes. Organic salts appeared promising as matrixes for analysis of natural products (NPs), including the imaging techniques, versus the co-crystals of neutral polyfunctional carboxylic acids. Seven model crystals of organic salts, and their matrix–analyte polycrystals, were comprehensively studied using the MALDI-MS and ESI-MS methods. The MS data were compared and supported by theoretical and experimental data, using quantum chemical methods, optical spectroscopy, and single crystal X-ray diffraction. The role of proton transfer (PT) effects in the desorption/ionization UV-MALDI processes was clarified.

Hydrogels based on carboxymethyl cassava starch cross-linked with di- or polyfunctional carboxylic acids: Synthesis, water absorbent behavior and rheological characterizations

Carboxymethyl cassava starch (CMS) was synthesized and its hydrogels were prepared by cross-linking it with di- or polyfunctional carboxylic acids using glutaric (CASXGLU), suberic (CASXSUB), pimelic (CASXPIM) and butanetetracarboxylic acids (CASBTC) as the cross-linkers. The characterization of the CMS showed that its degree of substitution was 0.86, average molar mass ( M w) was 5.6 × 10 6 g mol −1 and the 13C NMR showed strong peak at δ = 180.42 ppm which was assigned to the CO carbon in the carboxymethyl group. The absorption under load (AUL) and free swelling capacity (FSC) studies showed that the hydrogels have fast swelling properties and that they reached equilibrium after 1 h. Furthermore, all the hydrogels were sensitive to the increasing salt concentrations and pH of the medium. Both AUL and FSC reduced in saline solution while their values increased in alkaline buffer solutions. The result indicate that the difunctional carboxylic acids produced hydrogels with stronger material functions compared with the polyfunctional carboxylic acid and the order of increases in both AUL and FSC was CASXBTC, CASXPIM, CASXSUB and CASXGLU.

Synthesis of novel mono-and bisaminophosphoryl compounds and their membrane transport properties for acidic substrates

Some novel aminophosphoryl compounds were synthesized by the Kabachnik-Fields reaction. Their membrane transport properties for mono-and polyfunctional carboxylic acids with different number of functional groups were studied to establish that the transport rate of acidic substrates through liquid impregnated membranes increases in going from mono-to diphosphoryl carriers. Additional hydrophilic groups in the substrate molecule, too, affect transport efficiency.

Influence of the Cross-linking Agent on the Gel Structure of Starch Derivatives

Hydrogels were synthesized through cross-linking of carboxymethyl starch (CMS; Degree of Substitution DS = 0.45) using polyfunctional carboxylic acids (malic, tartaric, citric, malonic, succinic, glutaric and adipic acid). The syntheses used a cross-linking agent ratio (ratio of the number of cross-linking agent molecules to the number of monomer units constituting the polymer) of FZ = 0.05. After cross-linking the gels were dried, ground and then hydrogels of a polymer concentration of 4 mass-% were produced. These CMS-hydrogels were then rheologically characterized using dynamic oscillatory measurements. From measurements of the plateau region storage modulus G'P, the network parameters molar mass between two entanglement points Me (Me ranging from 9.318 (citric acid) to 281.397 g/mol (tartaric acid)), the cross-link density νe and the distance between two entanglement points ξ were calculated. Using carboxylic acids without other functional groups, a maximum in gel sturdiness is found at a spacer length of two CH2-groups. The evaluation of the loss factor tan δ for the CMS-hydrogels showed that values of tan δ = 0.2 varied only slightly with the frequency ω. Flow curves showed a pseudopIastic flow behavior for all CMS-hydrogels (the shear viscosity η declining over five decades in the range of the shear rate γ of 10−3 to 103 s−1) The different polyfunctional carboxylic acids have a strong influence on the sturdiness of the synthesized CMS-hydrogels.

Separation of butyltin and phenyltin species by ion-exchange chromatography with complexing mobile phases

Butyltin and phenyltin species have been separated by ion-exchange chromatography using silica-based and polymer-based columns. Mobile phases consisted of methanol-water mixtures containing polyfunctional carboxylic acids, which can act as complexing agents for organotin species. The best results were achieved with a system based on a methanol mobile phase containing malic and oxalic acids and a polymer-based column, which allowed the separation of tri- and diorganotin compounds and some resolution between monobutyltin and monophenyltin.

Mechanism of crosslinking of papers with polyfunctional carboxylic acids

AbstractBrief thermal curing of papers treated with an aqueous solution of polyfunctional carboxylic acids and NaH2PO4 imparts substantial wet strength to the papers. The effectiveness of such carboxylic acids increases with their functionality in the order 1,2,3,4‐butanetetracarboxylic acid (BTCA) > tricarballylic acid (TCA) ≫ succinic acid. The two main stages of the curing reaction of papers, i.e., pendant attachment of the polyfunctional carboxylic acids via esterification with cellulosic hydroxyl groups, and its further reaction with another cellulose hydroxyl group producing crosslinks of the cellulose fibers were analyzed separately using a combination of acid‐base and conductometric titrations. The extent of reaction of the polyfunctional carboxylic acids with paper was followed by pH titration, which shows the total decrease in acid functions as the curing progresses and is directly related to the total consumption of carboxylic acids groups by ester attachment and ester crosslinking steps. The conductometric titration, on the other hand, measures the increase in carboxylic acids bound to cellulose units of the paper as a direct result of previous esterification steps. Our studies reveal that the reaction of BTCA with papers is essentially quantitative after 15 min of curing. The amount of once‐reacted BTCA increases in the initial phases of the curing reaction and then decreases as more and more carboxylic acid units are converted into crosslinking sites, while the amount of crosslinked BTCA increases throughout the curing reaction. The reaction profile of papers with TCA differs from that of BTCA in that the curing reaction is initially dominated by the formation of ester appendages; crosslinking becomes the main reaction only after extended curing times. We attribute this difference to the ability of BTCA to form an highly reactive difunctional crosslinking reagent at the outset of the curing reaction, while TCA is initially monofunctional in its reaction with cellulosic hydroxyl groups (formation of a monoanhydride). The relationship between the wet tensile strength of the treated papers and their degree of crosslinking is also discussed. © 1995 John Wiley & Sons, Inc.

Polyfunctional Carboxylic Acids as Coprecipitating Agents For Barium, Yttrium, and Copper

ABSTRACTThe suitability of several polyfunctional carboxylic acids as coprecipitating agents for Ba, Y, and Cu was investigated. Essentially complete precipitation from alcoholic solutions was achieved for all three metals when tartaric acid was employed as the precipitating agent. The amorphous precipitate formed under these conditions was composed of uniform particles about 50 nm in diameter, and was converted readily to high purity Ba2YCu3O7−x.

Ionic polymerisation as a means of end-point indication in non-aqueous thermometric titrimetry. Part VIII. Solvent effects in the determination of polyfunctional carboxylic acids and phenols

A systematic study has been made of the effect of the solvent for the sample on the end-point sharpness and the reaction stoicheiometry in the catalytic thermometric titration of polyfunctional carboxylic acids and polyhydric phenols. Acrylonitrile was used as the end-point indicator.The mechanisms proposed for the reactions involved in the neutralisation and indicator processes are based on the assumption that the titrants can exist as mixtures of ion pairs, solvent-separated ion pairs and free ions in the sample solution. It is suggested that the ratio of free ions to ions pairs is the factor that controls the reaction stoicheiometry, and the cation solvating power of the solvent is more important than the dielectric constant of the solution in influencing this ratio.Solvent and titrant combinations are recommended for the determination of the total acidities of a range of benzene carboxylic acids, polyhydric phenols and hydroxybenzoic acids by the catalytic thermometric procedure.