Length Of Alkyl Substituent Research Articles

Синтез производных класса 2-алкил-5-фенил-4,5,6,7- тетрагидро-[1,2,4]триазоло[1,5-a]пиримидин-7-ола

The problem of acid corrosion of steel is of significant importance, particularly in the context of the oil extraction industry, where acid treatment of wells and surrounding spaces is widely employed. This research article focuses on the synthesis and investigation of previously unstudied derivatives of the class of 2-alkyl-5-phenyl-4,5,6,7-tetrahydro-[1,2,4]triazolo[1,5-a]pyrimidin-7-ols – organic compounds potentially highly effective as inhibitors of acid corrosion of steel. The method for synthesizing the proposed compounds involves the condensation of 3-alkyl-5-amino-1H-1,2,4-triazoles with cinnamaldehyde. The structure of the synthesized compounds has been confirmed using 1H NMR and LCMS methods. The study has revealed that the developed synthesis conditions yield the target tetrahydrotriazolopyrimidinols with alkyl substituents containing up to three carbon atoms. However, an increase in the length of alkyl substituents intensifies side reactions, making the isolation of the target compounds challenging. The obtained research results are significant for the development of effective organic inhibitors of acid corrosion of steel of a new class. These findings can serve as a basis for further research in this area, contributing to the development of new methods for corrosion prevention and improving the resistance of materials used in the oil industry. Thus, this study not only describes a new synthetic approach to obtaining inhibitors of corrosion in the tetrahydrotriazolopyrimidinol class but also holds prospective practical value in the field of industrial technologies and materials science.

SYNTHESIS OF POLYACRYLAMIDE HYDROGELS WITH PORPHYRIN FRAGMENTS IN THE SIDE CHAIN IN THE PRESENCE OF IMIDAZOLIUM IONIC LIQUIDS

The acrylamide hydrogels containing the porphyrin fragments have been obtained by radical polymerization in a solution. The synthesis has been carried out in the presence of imidazolium ionic liquids with length of the alkyl substituent in the imidazolium ring from C4 to C8. The influence of the used ionic liquids on the structure and some properties of the resulting porphyrin-containing acrylamide hydrogels has been established. The addition of an ionic liquid with a different length of the alkyl substituent into the reaction system can influence the structural changes that occur with the porphyrin comonomer during copolymerization with acrylamide. The formation of bacteriochlorin-like structures is inhibited in the presence of an ionic liquid in the reaction medium. This effect is most noticeable when using an imidazolium ionic liquid with a C8 alkyl substituent length. Hydrogels synthesized in the presence of ionic liquids have lower specific surface area compared to ones obtained without the use of ionic liquids. The lowest specific surface area values were shown by hydrogels synthesized using 1-octyl-3-methylimidazolium bromide. It was also found that the introduction of ionic liquid into the reaction mixture can contribute to both increase and decrease in the numerical values of the sorption characteristics of the resulting hydrogels, depending on the length of the alkyl substituent in the imidazolium ring and a porphyrin : acrylamide ratio. Hydrogels synthesized using 1-hexyl-3-methylimidazolium bromide and 1-octyl-3-methylimidazolium bromide at an initial porphyrin : acrylamide ratio of 1:20 have the highest degree of swelling. Varying the ratio of the initial monomers and the structure of the imidazolium ionic liquid during the copolymerization process allows to control the physicochemical characteristics of the resulting porphyrin-containing hydrogels, which can be useful for solving various applied problems. For citation: Pechnikova N.L., Smirnov A.S., Lyubimtsev A.V., Aleksandriiskiy V.V., Ageeva T.A. Synthesis of polyacrylamide hydrogels with porphyrin fragments in the side chain in the presence of imidazolium ionic liquids. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 6. P. 73-79. DOI: 10.6060/ivkkt.20246706.7053.

Self-Assembly Mechanism and Analysis of Smectic Mesophase Induction in Binary Systems of 4-(4-Alkoxyphenylazo)benzonitriles and Dodecyloxybenzoic Acid

Using a combination of experimental methods (polarizing optical microscopy, IR spectroscopy), the two-component systems consisting of 4-dodecyloxybenzoic acid (BA) and 4-(4-alkoxyphenylazo)benzonitriles (BN-n, n = 8, 10, 12) have been studied. The mesophase existence ranges of the systems depending on the length of alkyl substituents of the component BN-n were established. The possibility of formation as well as stability of heterodimeric complexes with a hydrogen bond –COOH···NC – were analyzed by DFT/B97D/6-311++G** method. In all obtained equimolar BN-n:BA (1:1) systems SmA phase was induced, which manifests itself enantiotropically in wide temperature ranges. With the help of computer simulation, it was shown that, unlike homodimers, the expected BN···BA H-complex has an angular structure, which cannot ensure the formation of the SmA phase. To elucidate the mechanism of mesophase formation in BN-n:BA systems, we calculated the energies of intermolecular interaction in homo- and heterodimers, and analyzed the experimental IR spectra of equimolar BN-n:BA systems. The spectra represent a superposition of the spectra of associates BN···BN and cyclic dimers of acid BA···BA. Therefore, we suggest that the BN···BA type H-complexes cannot form in equimolar BN-n:BA mixtures. Instead, a structure consisting of alternating layers of BA···BA dimers and BN···BN associates is formed. The layers of the acid dimer play the main role in the formation of SmA phase. It is noted that –COOH group, in contrast to such proton-donor groups as –NH2, –NH–, –OH, does not form hydrogen bonds with the proton-acceptor –CN group.

The Japanese quail chorioallantoic membrane as a model to study an amphiphilic gradient copoly(2-oxazoline)s- based drug delivery system for photodynamic diagnosis and therapy research

Amphiphilic gradient copoly(2-oxazoline)s are widely researched in the field of drug delivery. They could be used as a transport system for hydrophobic drugs such as hypericin (HYP). We prepared six gradient copolymers (EtOx)-grad-(ROPhOx) by living cationic ring-opening polymerization of a hydrophilic comonomer 2-ethyl-2-oxazoline (EtOx) and a hydrophobic comonomer 2-(4-alkyloxyphenyl)-2-oxazoline (ROPhOx), with different composition ratio (88:12 and 85:15) and three different alkyl chain lengths of alkyl (R) substituents. As an experimental model, Japanese quail chorioallantoic membrane (CAM) was used. The effect of nanoparticles loaded with HYP was evaluated by the changes of fluorescence intensity during photodynamic diagnosis (PDD) monitored under 405 nm LED light before administration, and 0,1,3 and 24 h after topical administration. The effectiveness of photodynamic therapy (PDT) (405 nm, 285 mW/cm2) applied 1h after the administration of HYP-loaded nanoparticles was evaluated using vascular damage score and histological sections. Molecular analysis was done by measuring angiogenesis-related gene expression by qPCR. The application of nanoparticles unloaded or loaded with HYP proved to be biocompatible, non-toxic, and undamaging to the CAM tissue, while they successfully altered the HYP fluorescence. We observed a possible anti-angiogenic potential of prepared nanoparticles, which could present an advantage for PDT used for tumour treatment.

(Invited) Metalation Effect on Diketopyrrolopyrrole-Tetrabenzoporphyrin Conjugate As p-Type Material in BHJ Organic Photovoltaics

Organic photovoltaics have attracted much attention for the next generation of photovoltaics. Tetrabenzoporphyrin (BP) is a p-type organic semiconductor characterized as the large, rigid p-framework, excellent stability, and good photoabsorption capability. Because of the low solubility, thermal precursor approach is necessary for the deposition of BP by solution process, where a soluble precursor (CP) of BP is spin-coated on the substrate, followed by annealing of CP film to make BP film by in-situ retro-Diels-Alder reaction of CP.[1,2] In 2017, we reported side-chain engineering for efficient photocurrent generation using a series of diketopyrrolopyrrole (DPP)–tetrabenzoporphyrin (BP) conjugates named Cn-DPP–BP (n = 4, 6, 8 or 10 depending on the length of n-alkyl groups on the DPP unit) as p-type materials in BHJ OPVs in combination with PC61BM as a n-type material by the thermal precursor approach.[3] The comparative study shows that the short-circuit current density largely depends on the length of alkyl substituents, ranging from 0.88 mA cm-2 with C10-DPP–BP to 15.2 mA cm-2 with C4-DPP–BP. C10-DPP–BP in the film is edge-on orientation dominant while that of C4-DPP–BP is face-on orientation dominant.Encouraged with the results, we synthesized a zinc complex of C4-DPP-CP (C4-DPP-ZnCP) as a soluble precursor of C4-DPP-ZnBP to investigate the effect of metalation of the porphyrin cavity for the BHJ OPV performance. BHJ OPV was prepared by thermal precursor approach: spin-coating of a mixed solution of the precursor, C4-DPP-ZnCP, and PC61BM, followed by annealing at 200 ºC to make a blend film of C4-DPP-ZnBP and PC61BM. Interestingly, the energy gap and ionization potential of C4-DPP-ZnBP film and C4-DPP-BP film are similar to each other, but the Jsc of C4-DPP-ZnBP is 1.5 times larger than that of C4-DPP-BP. We will discuss the relationship between film morphology and OPV performance by studying the blend film of C4-DPP-ZnBP/PC61BM by atomic force microscopy (AFM), X-ray diffraction (XRD) analysis and p-polarized multiple-angle incidence resolution spectrometry (p-MAIRS).References H. Yamada, T. Okujima, N. Ono, Chem. Commun. 2008, 2957-2974. H. Yamada, D. Kuzuhara, M. Suzuki, H. Hayashi, N. Aratani, Bull. Chem. Soc. Jpn. 2020, 93, 1234-1267. K. Takahashi, D. Kumagai, N. Yamada, D. Kuzuhara, Y. Yamaguchi, N. Aratani, T. Koganezawa, S. Koshika, N. Yoshimoto, S. Masuo, M. Suzuki, K. Nakayama, H. Yamada, J. Mater. Chem. A 2017, 5, 14003-14011.

Synthetic ion channels: functional characterization of benzo-crown ether based derivatives

Several benzo-crown ether derivatives have been reported in chemical literature to exhibit ion channel activity but very little is known about their permeation and gating mechanisms. In this study, we characterize two new families of benzo(crown-ether) compounds, termed monoacylated and monoalkylated benzo(crown-ethers) (MABCE). Depending on the length of alkyl substituents, size of the macrocycle, and ionic conditions, MABCE compounds are able to potently inhibit bacterial growth and transport ions across bacterial and synthetic membranes.

Investigation of the intermolecular voids at the dissolution of CO2 in ionic liquids

Empty intermolecular volume in pure liquids and solutions is an important factor determining the mobility of molecules and the ability to dissolve other substances. The investigation of computer models gives insight into the role of intermolecular voids in these processes. In this work, we demonstrate an application of the Voronoi-Delaunay method to describe quantitatively the voids in ionic liquids on the example of the dissolution of carbon dioxide. Molecular dynamics models of 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Cnmim][NTf2]) ionic liquids (ILs) with different lengths of the alkyl substituent n (from 2 to 8 carbon atoms in the alkyl chain), as well as their mixtures containing CO2 at different concentrations have been studied. The contributions of the anions and the cations to the empty volume of the pure ILs and the mixtures are studied. It was shown that the increase in the empty volume with the growth of the alkyl substituent length of the cation is mainly determined by the methyl groups of the substituent, while the empty volume related to the anions and the imidazole ring of the cations practically does not change. CO2 molecules add additional empty volume to the mixture, instead of filling available voids preliminarily formed in a pure IL. The apparent molar volume of CO2 molecules in the studied ILs exceeds their intrinsic volume, defined as their Voronoi volume. However, the distribution of the interstitial spheres radii remains practically the same in the pure ILs and in the mixtures. Moreover, the radial distribution of large intermolecular voids (comparable to the size of a CO2 molecule) in pure ILs does not correspond to the real distribution of CO2 molecules in the mixtures.

Reactive Amphiphilic Aprotic Ionic Liquids Based on Functionalized Oligomeric Silsesquioxanes

Abstract This paper discusses a method for the synthesis of ionic liquids which are mixtures of oligomeric silsesquioxanes (OSS) of polyhedral structure and their analogs with open chains containing aprotic cationic ionic groups with different lengths of alkyl substituents and reactive hydroxyl groups in the organic shell (OSS-ILs). This method includes the quaternization reaction of OSS with tertiary amine and primary and secondary hydroxyl groups by n-bromopropane or n-bromodecane. Obtained compounds were amorphous with glass transition temperature below 0 °C. The ionic conductivity of OSS-ILs increases with decreasing the alkyl substituent length and reaches 1.4·10−3 S/cm at 120 °C. Dynamic light scattering reveals that the length of alkyl substituent of OSS-ILs affects the assembly behavior in aqueous solutions. According to atomic force microscopy images, the surface morphology of the film of OSS-IL with short substituents showed disk-like flat micelles with an average diameter of 229 ± 92 nm and height of 2 nm. OSS-IL with long substituents formed polydisperse micellar morphologies, of which a majority showed elongated, worm-like structures with an average height of 2 nm. The ability to endow ionic conductivity and to tune morphology makes these materials promising as potential polymer electrolytes for various electrochemical applications, in particular ionic sensors and energy storage devices.

Systematic Merging of Nonfullerene Acceptor π-Extension and Tetrafluorination Strategies Affords Polymer Solar Cells with >16% Efficiency.

The end-capping group (EG) is the essential electron-withdrawing component of nonfullerene acceptors (NFAs) in bulk heterojunction (BHJ) organic solar cells (OSCs). To systematically probe the impact of two frequent EG functionalization strategies, π-extension and halogenation, in A-DAD-A type NFAs, we synthesized and characterized four such NFAs: BT-BIC, LIC, L4F, and BO-L4F. To assess the relative importance of these strategies, we contrast these NFAs with the baseline acceptors, Y5 and Y6. Up to 16.6% power conversion efficiency (PCE) in binary inverted OSCs with BT-BO-L4F combining π-extension and halogenation was achieved. When these two factors are combined, the effect on optical absorption is cumulative. Single-crystal π-π stacking distances are similar for the EG strategies of π-extension. Increasing the alkyl substituent length from BT-L4F to BT-BO-L4F significantly alters the packing motif and eliminates the EG core interactions of BT-L4F. Electronic structure computations reveal some of the largest NFA π-π electronic couplings observed to date, 103.8 meV in BT-L4F and 47.5 meV in BT-BO-L4F. Computed electronic reorganization energies, 132 and 133 meV for BT-L4F and BT-BO-L4F, respectively, are also lower than Y6 (150 meV). BHJ blends show preferential π-face-on orientation, and both fluorination and π-extension increase NFA crystallinity. Femto/nanosecond transient absorption spectroscopy (fs/nsTA) and integrated photocurrent device analysis (IPDA) indicate that π-extension modifies the phase separation to enhance film ordering and carrier mobility, while fluorination suppresses unimolecular recombination. This systematic study highlights the synergistic effects of NFA π-extension and fluorination in affording efficient OSCs and provides insights into designing next-generation materials.

Influence of the nature of organic solvents on the process of separation of antioxidative additive in a transformer oil by a gas-chromatographic method

THE PURPUSE. The paper considers the influence of the nature of organic solvents on the process of separation of an antioxidant additive added to transformer oil at a concentration of up to 0.40% by weight, and organic solvents used as selective extractants. Based on the analysis of literature data, it is shown that mineral transformer oil is a complex hydrocarbon composition that undergoes oxidative degradation during operation, leading to aging of transformer oil and deterioration of technical conditions of operation of transformer electrical equipment. As a result of this process, peroxide compounds appear in transformer oil, which affect its color, oxidation stability, aging resistance, compatibility with structural parts of equipment, etc. Gas -liquid chromatography was used to determine the "Ionol" antioxidant additive and organic extractants in transformer oil. Experiments were performed on a chromatograph of Chromosomes GC -1000 with a flame ionization detector and a quartz capillary column 30 m long, 0.32 mm in diamet er, filled with a fixed liquid phase Valko Bond VB-WAX P/n with a film thickness of 0.5 microns. The sample was dosed into the gas-liquid chromatograph injector using an automatic liquid dispenser DAZH-23, designed for entering up to twenty-three samples of sorbates and controlled by a computer with the appropriate software.METHODS. Aliphatic alcohols from C1 to C5 were studied as extractants of the antioxidant additive, which are well separated from the ionol both under isothermal conditions and in the mode of linear programming of the column temperature from 40 to 220 °C. Under these conditions the chromatogram of the separation of antioxidant additives, and aliphatic alcohols, which are used to calculate their relative retained volumes, the asymmetry of chromatographic peaks and the column efficiency, which depends on the physico -chemical nature of the solutes to be analyzed and the conditions of the chromatographic experiment.RESULTS. The dependence of the relative volume of retention of aliphatic alcohols on their permittivity, which has a nonlinear form, is established. At the same time, with a decrease in the chain length of alkyl substituents in the aliphatic alcohol molecule, there is a tendency to increase their permittivity. The dependence of the relative retained volume of aliphatic alcohols on the selectivity coefficient of separation with Ionol is linear. In this case, the most optimal separation selectivity, approaching one, is characteristic of the Ionol – Butanol-1 pair. It is shown that the dependence of the logarithm of the retention time of aliphatic alcohols on their boiling points is linear both at a low temperature of the chromatographic column (40 °C) and at a higher temperature (more than 100 °C). CONCLUSION. At the same time, the angle of inclination of the corresponding lines changes in the boiling point of organic solvents, which is associated with a change in the sorption mechanism in a capillary chromatographic column filled with a polar stationary phase.

Coupled mutual diffusion in aqueous (ammonium monovanadate + butyl-substituted sulfonated resorcinarene) solutions: An experimental and theoretical approach

Binary mutual diffusion coefficients (D) of aqueous solutions of the macrocyclic salt tetrasodium 5,11,17,23-tetrakissulfonatemethylen-2,8,14,20-tetra(butyl)resorcin[4]arene (Na4BRA) have been measured at 298.15 K by the Taylor dispersion method. The limiting diffusion coefficient of Na4BRA obtained by extrapolation of the data is used to evaluate the limiting conductivity and hydrodynamic radius of the BRA4− ion. The change in the hydrodynamic radius of sulfonated resorcinarenes with increasing the length of alkyl substituents is analysed. In the second part of this work, the effect of ammonium monovanadate on the diffusion of aqueous Na4BRA was investigated by measuring apparent ternary mutual diffusion coefficients for aqueous NH4VO3(1) + Na4BRA(2) solutions. In binary aqueous Na4BRA solutions (no added NH4VO3), the BRA4− ions diffuse at the same speed as the smaller and relatively mobile Na+ counterions to maintain electroneutrality. As the NH4VO3 concentration is raised, the main diffusion coefficient of NH4BRA drops to the tracer diffusion coefficients of BRA4− ions in supporting NH4VO3 solutions. Coupled diffusion of NH4VO3 and Na4BRA is significant. In particular, Na4BRA concentration gradients produce significant counter-current coupled flows of NH4VO3. Nernst equations are used to provide an electrostatic interpretation of the strongly coupled diffusion of Na4BRA and NH4VO3.

Thermal decomposition characteristics and potential hazards of three new ionic liquids of alkyl imidazoline hexafluorophosphates by TG and ARC

Imidazoline ionic liquids (IMILs) because of its unique performance in the synthesis, liquid phase extraction environment, energy and other fields have broad application prospects, for the safety of the unknown material, study the thermal decomposition characteristics and potential hazards is very necessary. The purpose of this study was to evaluate the risk of three IMILs during production, transportation, storage, and application using thermogravimetry (TG) and accelerating rate calorimeter (ARC). The influence of different lengths of alkyl substituents on ILs stability was systematically analyzed. The apparent activation energy (Ea) and pre–exponential factor (A) of IMILs were calculated by Flynn–Wall–Ozawa (F–W–O) and Coats–Redfern (C–R) methods. Then, the mechanical function of their decomposition reaction was obtained by using the C–R method. The kinetic compensation effect is discussed. Finally, according to the experimental data under adiabatic condition by accelerating rate calorimeter (ARC), it is proved that the runaway reaction of the three IMILs is slow. This study confirms the low potential harmfulness of the above three microorganisms, gives their safe temperature range, and provides a reference for their safe use.

Effects of alkyl-substituent length on photovoltaic performance of bulk heterojunction solar cells utilizing non-peripherally octaalkyltetrabenzotriazaporphyrins

We report alkyl-substituent length dependences of optical and electronic characteristics, crystal structures, and photovoltaic performances of bulk-heterojunction organic solar cells utilizing non-peripherally alkyl-substituted tetrabenzotriazaporphyrin (CnTBTAPH2). By extending the pentyl (n = 5) to octyl (n = 8) substituents, the molecular alignment was affected and the intercolumnar packing was probably modified from pseudo-hexagonal structure to 2D rectangular lattice. Furthermore, the devices utilizing the C5TBTAPH2 and C6TBTAPH2 discotic macrocycles with the short-alkyl-substituents exhibited a relatively high photovoltaic performance with a power conversion efficiency of around 4.7% in comparison with those utilizing the long-alkyl-substituted macrocycles. These differences in the device performance could be understood by taking the hole mobility and highest occupied molecular orbital energy level into consideration.

Synthesis of Zn(II) porphyrin dyes and revealing an influence of their alkyl substituents on performance of dye-sensitized solar cells

In this study, the series of A3B-type zinc porphyrin dyes have been synthesized for dye-sensitized solar cells (DSSC). All the received zinc-porphyrin complexes bear different alkyl substituents (none, tert-butyl-, methoxy-, hexyloxy-, dodecyloxy-, a pair of hexyloxy-), bulky electron-donating substituent (diphenylamino) in each of three meso-phenyl rings and carboxylic acid as acceptor/anchoring group. The influence of the number and length of alkyl chains on the photophysical properties and DSSCs photovoltaic performance was investigated, as well as quantum-chemical modeling was carried out. Our results reveal that the alkyl chains length and number affect cell performance. We found that DSSC power conversion efficiency increases with an increase in the length and number of alkyl substituents in the porphyrins. A maximum efficiency of 1.29 % was observed in solar cells with dodecyloxy-substituted zinc porphyrin.

Synthesis of Super Hydrophobic Disperse Dyes Having Long Alkyl Substituents and Their Dyeability onto Unmodified Polypropylene Fibers

The new series of super hydrophobic disperse dyes having different length of alkyl substituents was synthesized to dye pure polypropylene fibers. From butyl to dodecyl groups were introduced to an anthraquinoid chromophore. The adsorption interaction of the dyes toward the polypropylene fiber was increased with the increase of the length of alkyl chains due to enhancement of hydrophobicity of the dyes. The optimum alkyl group was determined as the longest dodecyl group in this study. Their absorption spectra in the visible range appeared almost the same regardless of the length of alkyl groups, which meant that the length of alkyl groups did not influence on optical properties of the dyes relating to color appearances. The color fastnesses of the dyed fabrics to washing, rubbing, and light were good enough for practical application.

Effect of Ionic Liquid Structure on the Electrochemical Response of Dopamine at Room Temperature Ionic Liquid‐modified Carbon Paste Electrodes (IL–CPE)

AbstractIn this work 12 different ionic liquids (ILs) have been used added as co‐binders in the preparation of modified carbon paste electrodes (IL–CPEs) used for the voltammetric analysis of dopamine in Britton‐Robinson buffer. The ionic liquids studied were selected based on three main criteria: (1) increasing chain length of alkyl substituents (studying 1‐ethylimidazolium and ethyl, propyl, butyl, hexyl and decylmethylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquids); (2) nature of the counter ion (dicyanamide, bis(trifluoromethylsulfonyl)imide and hexafluorophosphate) in 1‐butyl‐3‐methylimidazolium ionic liquids; and (3) cation ring structures (1‐butyl‐3‐methylimidazolium, 1‐butyl‐1‐methylpiperidinium, 1‐butyl‐1‐methylpyrrolidinium and 1‐butyl‐3‐methylpyridinium) in bis(trifluoromethylsulfonyl)imide or hexafluorophosphate (1‐butyl‐3‐methylimidazolium or 1‐butyl‐3‐methylpyridinium as cations) ionic liquids. The use of IL as co‐binders in IL–CPE results in a general enhancement of both the sensitivity and the reversibility of dopamine oxidation. In square wave voltammetry experiments, the peak current increased up to a 400 % when 1‐ethyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide was used as co‐binder, as compared to the response found with the unmodified CPE. Experimental data provide evidence that electrostatic and steric effects are the most important ones vis‐à‐vis these electrocatalytic effects on the anodic oxidation of dopamine on IL–CPE. The relative hydrophilicity of dicyanamide anions reduced the electrocatalytic effects of the corresponding ionic liquids, while the use of 1‐ethyl‐3‐methylimidazolium hexafluorophosphate or 1‐ethyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide (two relatively small and highly hydrophobic ionic liquids) as co‐binders in IL–CPE resulted in the highest electrocatalytic activity among all of the IL–CPE studied.

Synthesis and antibacterial activity of new dimeric pyridinium chlorides based on 2,2-bis(hydroxymethyl)propane-1,3-diyl spacer

New bispyridinium dichlorides based on 2,2-bis(hydroxymethyl)propane-1,3-diyl spacer were synthesized from pentaerythritol, 4-aminopyridine, and carboxylic acids. The resulting biocides possess a high antibacterial effect. The minimal inhibitory concentration (MIC) of these compounds against pathogenic bacteria, namely, gram-positive Methicillin-resistant Staphylococcus aureus (strain ATCC 25923) and gram-negative Escherichia coli (ATCC 25922) and Pseudomonas aeruginosa (ATCC 27853), was established. The influence of the alkyl substituent length in salts on their microbiological activity was studied.

Evaluation of Electrochemical Stability and Li-ion Interactions in Ether Functionalized Pyrrolidinium and Phospholanium Ionic Liquids

Potential electrolytes for lithium ion batteries (LIB) depicting high electrochemical stability and ionic conductivity still represents a great challenge. Herein, we investigate the reduction stability and Li+ cation interactions with substituted cyclic phospholanium (CylP5+) and pyrrolidinium (Pyr+) ionic liquids (ILs) with bis(trifluoromethanesulfonyl)imide (TFSI−) anion. The cations CylP5+ and Pyr+ are functionalized with varying chain lengths of alkyl and alkoxy substituents and their reduction potentials evaluated with respect to Li+/Li. CylP5+ cations, in general have better stability than Pyr+ based ILs, while the alkoxy substitution is found to lower the reduction stability compared to alkyl substituents in both ILs. Furthermore, the interaction energies between the substituent modified-cations (C), Li+ cation and the anion (A) were evaluated. The ion-pair (C-A) interaction energies on addition of Li+ cation is shown to decrease for both Pyr+ and CylP5+ cations with shorter alkoxy chain lengths, thereby implying faster diffusion of ions due to weaker interactions. Similarly, among the two cations, lowest ΔE were noted between alkoxy substituted [Li(CylP5)]2+ cation and TFSI−, signifying faster diffusion of ions in CylP5+ based electrolytes than that of Pyr+ based ILs. These results govern the synthesis of novel ILs with promising base cation and functionalization for LIB.

A Study of the Products of Alkylation of Turbine Oil Distillate with Catalytic Cracking Gases

The main physicochemical properties and structural parameters of the products of alkylation of the turbine oil distillate with catalytic cracking gases on Zeokar-600 and Omnikat-210P zeolite catalysts have been determined using IR, 1H NMR, and UV spectroscopy techniques. Alkylation has been carried out in the temperature range of 50–150°C at oil : gas ratios of 1 : 1 and 1 : 2. The reaction products have been studied. The products have been obtained under optimal conditions, ensuring the maximum increase in the viscosity index of the oil fraction from 32 to 75 and 53 on the Zeokar-600 and Omnikat-210P catalysts, respectively. It has been shown that the kinematic viscosity and viscosity index of the oil fraction are increased by the alkylation. This is due to an increase in the length and quantity of alkyl substituents of aromatic hydrocarbons by adding propylene and butylene units of olefin hydrocarbon gases of catalytic cracking.

PH-Sensitive N,N-Dimethylalkane-1-amine N-Oxides in DNA Delivery: From Structure to Transfection Efficiency.

pH-sensitive liposomes composed of homologues of series of N,N-dimethylalkane-1-amine N-oxides (CnNO, n = 8-18, where n is the number of carbon atoms in the alkyl substituent) and neutral phospholipid dioleoylphosphatidylethanolamine (DOPE) were prepared at two molar ratios (CnNO/DOPE = 0.4:1 and 1:1) and tested for their in vitro transfection activity. Several techniques (SAXS/WAXS, UV-vis, zeta potential measurements, confocal microscopy) were applied to characterize the system in an effort to unravel the relationship among the transfection efficiency, structure, and composition of the lipoplexes. The transfection efficiency of CnNO/DOPE for plasmid DNA in U2OS cells follows a quasi-parabolic dependence on CnNO's alkyl substituent length with a maximum at n = 16. The transfection efficiency of CnNO/DOPE (n = 12-18) lipoplexes was found to be higher than that of commercially available Lipofectamine 2000. C16NO/DOPE also positively transfected HEK 293T and HeLa cells. Small-angle X-ray scattering (SAXS) shows large structural diversity depending on the complex's composition and pH. Transfection efficiencies mediated by two structures, either a condensed lamellar (Lαc) or epitaxially connected Lαc and a condensed inverted hexagonal (HIIc) phase (Lαc & HIIc), were found to be very similar. The change in pH from acidic to neutral induces phase transition Lαc & HIIc → QII + Lα, with cubic phase QII of the Pn3m space group. QII detected in lipoplexes of most efficient composition CnNO/DOPE (n = 16 and 18) facilitates DNA release and promotes its internalization in the cell.