Synthesis of Some Novel Nonionic Ethoxylated Surfactants Based on α-Amino Acids and Investigation of Their Surface Active Properties

Eight novel ethoxylated nonionic surfactants were prepared based on oil soluble α-amino acids. The L-phenylalanine and L-leucine were esterified and amidated with cetyl alcohol and palamitic acid, respectively; two amides and two esters of α-amino acids were obtained. The ethylene oxide was condensed with the prepared amides and esters to get three different polyethylene oxide units (40, 60, and 100) as phenylalanine derivatives. The amide and ester of α-L-leucine were ethoxylated at (60 ethylene oxides units). The analytical micro analysise, FTIR, ¹H NMR, ¹³C NMR, mass spectra were carried out to confirm the chemical structures. The surface tension of the water soluble prepared compounds was measured at 25°C, further the surface active properties were determined and calculated. Such that critical micelle concentration (CMC), surface excess (Γ_max); area per molecule (A_min), effectiveness (γ_CMC) free energy of micellization and adsorption (ΔG_mic, ΔG_ad). From the data obtained it was found that the CMC of phenylalanine esters is greater than that obtained for the amide derivatives. The Γ_max decreased as the ethylene oxide units (EO) increased. It was found also that the ΔG_ad was greater than the ΔG_mic. The obtained data and discrepancy were discussed on the light of surfactant chemical structure.     

Solubility, Acid–Base and Complexation Properties of Calix[4]resorcinarene in Aqueous Solutions of Nonionic Surfactants

Solubility and acid–base properties of calix[4]resorcinarene (H₈L) in aqueous solutions of nonionic surfactants Triton X-100, Triton X-405, and Brij-35, as well as isopropanol were studied by pH-potentiometry. The dependence of the amount of a nonionic surfactant necessary to dissolve H₈L on the length of ethylene oxide chain was found. The dissociation constants of macrocycle for the first four steps are low sensitive to the medium nature (micellar or water–alcohol solutions). Complexation ability of the [H_{8 – n} L] ^n– anions with respect to tetramethyl- and tetraethylammonium, N-methylpyridinium, and [Co(En)₂(C₂O₄)]⁺ cations was studied by pH-potentiometry. A noticeable increase in the selectivity of guest–host binding was found on going from aqueous or water–alcohol to micellar solutions.     

Synthesis and Acid-Base Properties of Tetraphenylporphine Derivatives with Amino Acid “Anchor” Groups

Russian Journal of General Chemistry - Asymmetrically substituted 5,10,15,20-tetraphenylporphyrin derivatives such as 5-(4-aminophenyl)10,15,20-triphenylporphine,...     

Acid–Base Properties of Polyhalogenated Tetraphenylporphyrins

Russian Journal of Organic Chemistry - [2,3,7,8,12,13,17,18-Octabromo-5,10,15,20-tetrakis(2,6-dichlorophenyl)porphyrinato]zinc(II) and...     

Synthesis and Acid–Base Properties of β-Octabromo-Substituted Unsymmetrical Nitrophenylporphyrins

Russian Journal of Organic Chemistry - The bromination of [5-(4-nitrophenyl)-10,15,20-triphenylporphyrinato]cobalt(II) and [5,10,15-tris-(4-nitrophenyl)-20-phenylporphyrinato]cobalt(II) with...     

Surface Acidic Properties of Loaded Heteropoly Acid and Preparation of Dimethylether by Catalyzed Dehydration of Methyl Alcohol

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Synthesis,Characterization, and Antimicrobial Evaluation of Quinoline-Oxadiazole–Based Azetidinone Derivatives

A series of 3-chloro-1-(aryl)-4-(2-(2-chloroquinolin-3-yl)-5-(pyridin-4-yl)-1,3,4-oxadiazol-3(2H)-yl)-4-ethyl-azetidin-2-ones (5a–l) have been synthesized and characterized by IR, ¹H NMR, and¹³C NMR. Synthesized compounds were screened for their antimicrobial activity against different strains of bacteria (E. coli, P. aeruginosa, S. aureus, S. pyogenes, C. albicans, A. niger, and A. clavatus). On the basis of statistical analysis, it has been observed that compounds had significant correlations.     

Synthesis and Properties of Gemini Cationic Surfactants with Amide Spacers

Four gemini cationic surfactants {N,N‘-di[2-(lauryldimethylamino)acetyl]polymethylenediamine dichloride, LAA-s-LAA, s = 2,3,4,6 } were synthesized by using four bis (a-chloroacetamide)s and N, N-dimethyl-laurylamine, respectively. The molecular structures were characterized by means of IR, ^1H NMR. ^13C NMR and MS, and the behavior of their aqueous solutions was studied. The critical micell concentrations (CMC) of LAA-s-LAA were one order of magnitude lower than that of dodecyltrimethyl ammonium chloride (DTAC). With the change of the length of spacer chain(s), their CMC values change, and CMC reaches the top value at s=4.     

Synthesis and Properties of Novel Cationic Maleic Diester Polymerizable Surfactants

The surfactants used in the emulsion polymerization can be thereafter the source of many problems for the application, such as adhesives and coatings. To overcome these negative aspects essentially related to their mobility in the final polymer, surfactants can be covalently linked to the particle surface through incorporation into the polymer chains. Recent years, polymerizable surfactants (surface active monomer or surfmer) are widely reported and used in the emulsion polymerization, many po…     

Surface and Catalytic Properties of TiO2–ZrO2 Mixed Oxides

This paper reviews acid–base bifunctional catalysis and surface properties (morphology, composition, specific area, acidity/basicity, site density) on TiO₂–ZrO₂ (abbreviated as TZ) mixed oxides. The phase change from crystalline single oxides (TiO₂ and ZrO₂) to amorphous TZ mixed oxide results in decreasing grain size and site density, increasing surface area, acid/base amount and strength, and better activity/selectivity. Different acid–base bifunctional mechanisms (concerted, go-together, stepwise) were proposed to interpret the reaction behavior of various reactions (esterification, dehydration, dehydrogenation, isomerization, dehydrocyclization) over the acid–base bifunctional TZ catalysts.     

Synthesis of β–Amino Acid Derivatives

In recent years, β-amino acids and their derivatives have attracted considerable attention due to their occurrence in biologically active natural products, such as dolastatins, cyclohexylnorstatine and Taxol. β–Amino acids also find application in the synthesis of β–lactams, piperidines, indolizidines. Moreover, the peptides consisting of β–amino acids, the so-called β–peptides, have been extensively studied recently. Consequently, considerable efforts have been directed to the synthe…     

Synthesis and Acid–Base,Absorption, and Fluorescence Properties of Phthalocyanine Derivatives

Russian Journal of General Chemistry - Tetrakis{5,6-bis(4-tert-butylphenyl)pyrazino[2,3-c]}porphyrazine and tetra(4-tert-butyl)phthalocyanine have been synthesized, and their acid–base...     

Synthesis of Macrocycles Containing Amino Acid Ester and Aryl-heterocyclic Units

AmongmanynatUraImacrocycleswithbiologicalactivity,therearealInostsomekeystrUctUreunitS.ForinStance,thereareesterresidueinmacrocycliclactonesI'],andaminoacidresidueincycIopeptidesI'].Thesyntheticmacrocycles,ontheotherhand,havebeenfocusedoncrownether,whichhavebeenwelldevelopedfrOmsingleoxygen-containingcrownethertoaza-,thiaandaZahiacrownether.BecauseoftheirspecialtyasenZyInemodels,theyhavebeingcloselycormectedwithBiomirneticChemisnyl'].lnordertoboitatethecomplexnatUrlmacrocycles,weusednat…     

Acid–Base Properties of Macroporous Weak Base Anionite Based on Aminated Acrylonitrile/Divinylbenzene Copolymer

Potentiometric titration of weak base anionite (the degree of crosslinking was 12–16%) was performed within the pH range of 2–12 and NaCl concentration range of 0.1–1.0 mol/L. The maximum ionexchange ability against HCl does not depend on the solution ionic strength and is 6.50 ± 0.12 mmol/g of dry solid matter. It was shown that the process of acid–base equilibrium can be adequately described by the Gregor equation within the studied stock electrolyte concentration and pH ranges. Two type of groups were discovered in anionite. The ionization constants of these groups differ by three orders of magnitude. The existence of amino groups of different nature was proved by the data obtained by functional analysis; it was estimated that the acidity of these groups decreases as NaCl concentration increases.     

Synthesis and Properties of Aromatic Side Chained N‐Acyltaurate Surfactants

A series of anionic N‐acyltaurate surfactants, side chain containing aromatic nucleus (abbreviated as SAATT), were synthesized via Williamson reaction, hydrolyzation, and acylation. Krafft temperatures and surface properties of these surfactants at 30°C, that is, critical micelle concentration, cmc, surface excess concentration, Γ_max, surface area demand per molecule, A _min, efficiency in surface tension reduction, pC₂₀, effectiveness in surface tension reduction, π_cmc, and cmc/C₂₀ parameter were determined. It was shown that these surfactants exhibit good solubility which was confirmed by measuring Krafft temperature. The cmc of SAATT was much smaller than that of conventional surfactants with similar effective carbon numbers, and shifted to lower concentration with increasing hydrocarbon chain length. In addition, the γ_cmc decreased with decrease in Γ_max. The pC₂₀ and the cmc/C₂₀ got larger with the increase in hydrocarbon chain length. From the fluorescence intensity ratios of I ₁ (373 nm) and I ₃ (384 nm) using pyrene as a probe, it was indicated that the molecules of SAATT formed loose micelles with a broad size distribution.     

Oil Solubilization Capacity,Liquid Crystalline Properties,and Antibacterial Activity of Alkanolamine‐Based Novel Cationic Surfactants

A series of monomeric and dimeric cationic surfactants with tuned polarity was synthesized. Oil solubilization capacity, thermotropic liquid crystalline properties, and minimum inhibitory concentration (MIC) of novel hydroxylated cationic surfactants using selected gram positive and gram negative bacteria were examined. Antibacterial activity and the propensity of gemini surfactants for oil solubilization were observed to be better than those of corresponding monomeric surfactants. Pseudo ternary phase diagrams for these surfactants, methyl methacrylate (MMA), and water clearly showed, that microemulsions can be easily formulated with all these surfactants. Solubilization and foam studies of mixed surfactant systems were also examined. Molecular architecture like the tail length, head group area, and presence of ethanolic goups in the surfactant affect the performance properties. Unlike conventional gemini surfactants the synthesized gemini surfactants also show thermotropic liquid crystalline properties (smectic‐A, L_α phase).     

Combination of Derivatization–HPLC–MS and Enzymatic Hydrolysis–Edman Degradation for Amino Acid Sequence and Configuration of Polymyxin B Components

Chromatographia - An analysis strategy that can simultaneously determine the amino acid site information and configuration for polymyxin (PM) components is reported in this study. The main...     

Synthesis and Surface Activity of Novel Triazole—based Cationic Gemini Surfactants

Gemini surfactants, which contain two hydrophilic groups and two hydrophobic groups in the molecule, are considered as a new generation of surfactants. These surfactants are about 3 orders of magnitude more efficient at reducing surface tension and more than 2 orders of magnitude more efficient at forming micelles than conventional surfactants1. During recent years, many gemini surfactants have been synthesized, and a considerable number of investigations have been reported on their unusua…     

Chromatographic Properties for Enantiomeric Separation of Amino Acid Derivatives on the Molecularly Imprinted Monoliths

Since their introduction in 1992 by Fréchet and Svec[1], monolithic supports as stationary phases in high performance liquid chromatography (HPLC) and capillary electrochromatography (CEC) have gained significant interest due to a number of unique properties. Their ease of preparation, high reproducibility, versatile surface chemistry and fast mass transport are advantageous in a variety of applications[2-4]. Separations in diverse chromatographic modes have been performed in either HPLC or CEC, showing their strong point for high-speed separations of biological and synthetic molecules[5-12]. Although a number of papers have been reported on the application of monolithic supports as chiral stationary phases in CEC and pressure-assisted capillary electrochromatography (p-CEC)[13-19], few reports have so far been published on chiral monolithic stationary phases for liquid chromatography[20].