Kinetic and spectroscopic investigations of aqueous micelles of cationic surfactants

The aqueous micellar solutions of monocationic surfactants N-hexadecyl-N,N,N-trimethylammonium bromide (CTABr), N-hexadecyl-N,N,N-trimethylammonium nitrate (CTANO₃), N,N,N-tributyl-N-hexadecylammonium bromide (CTBABr) and gemini surfactants 1,4-bis(N-hexadecyl-N,N-dimethylammonium)ethane dibromide (C-E-C2Br), 1,4-bis(N-hexadecyl-N,N-dimethylammonium)propane dibromide (C-P-C2Br), and 1,4-bis(N-hexadecyl-N,N-dimethylammonium)butane dibromide (C-B-C2Br) were studied with a solvatochromic probe, 2,6-diphenyl-4-(2,4,6-triphenylpyridinium-1-yl)phenolate, better known as Reichard’s ET-30 dye. The local polarity at the probe site (E_T) was calculated from the wavelength maximum of the lowest-energy intramolecular charge-transfer ϖ-ϖ* absorption band of ET-30. The results were compared with a kinetic investigation of the cyclization of 2-(3-bromopropyloxy)phenoxide (PhBr7) in micelles; this reaction is a model for S_N2 reactions and it depends on medium polarity.     

Isolation and characterisation of products from the reactions between [Co2(nta)2(μ-OH)2]2− and different ligands. The crystal structure of [Co(nta)(N,N-Et2en)]

The crystal structure of [Co(nta)(N,N-Et₂en)] (nta = nitrilotriacetate and N,N-Et₂en = N,N-diethylethylenediamine) was determined from three-dimensional X-ray diffraction data. The substituted nitrogen of N,N-diethylethylenediamine is bonded trans to the nta nitrogen with the Co—N_{(N,N Et2en)}= 2.011(5) and Co—N_(nta) = 1.950(4) Å while the cis Co—N bond is 1.953(4) Å. The Co—O bond lengths are 1.905(2) and 1.884(4) Å respectively.     

Synthesis of Isatin Derivatives

Reactions were studied of isatin sodium salt with bromocyclohexane, p-ethoxyphenyl chloroethyl ketone, 4,4'-di(chloromethyl)biphenyl, and 4,4'-(dichloromethyl)diphenylmethane. N-cyclohexylisatin, p-ethoxyphenyl N-isatinoethyl ketone, 4,4'-di(N-isatinomethyl)biphenyl, 4-chloromethyl-4'(N-isatinomethyl)biphenyl, 4,4'-di(N-isatinomethyl)diphenylmethane, 4-chloromethyl-4'(N-isatinomethyl)diphenylmethane, and 4-(N-morpholinomethyl)-4'-(N-isatinomethyl)diphenyl were synthesized.     

Synthesis of 2-amino-4-imino-4,5-dihydrothiazoles from N-sulfonyl-α-chloroamidines and thiourea

A number of new and interesting 2-amino-4-(N-substituted)imino-4,5-dihydrothiazoles were synthesized by reacting thiourea (or thiourea hydrochloride) with N-alkyl- or N,N-dialkyl-N′-p-toluenesulfonyl-α-chloroacetamidines, where the N,N-alkyl groups were ethyl, cyclohexyl, benzyl, β-phenethyl, (3,5-dimethyl-1-adamantyl)-methyl, as well as N,N-dimethyl- and N,N-pentamethylene. Reactions of N-alkyl-N-p-toluenesulfonyl-2-chloroacetamidines (substituents being N-ethyl, N-benzyl and N,N-dimethyl) with thiourea hydrochloride in hot 2-propanol furnished 2-amino-4-(p-toluenesulfonyl)imino-4,5-dihydrothiazole (in 51, 60 and 65% yields, respectively) and the corresponding amine hydrochloride. In hot acetone or butanone, the reactions of these N-sulfonyl-2-chloroacetamidines with excess thiourea provided 2-amino-4-N-(alkyl or N,N-dialkyl)imminium-4,5-dihydrothiazole chlorides in 25–80% yield. The by-product from these reactions was p-toluenesulfonamide. The structures of the products were established by chemical transformations and spectral methods (nmr and mass spectra).     

Syntheses of N-substituted carbazoles involving polymerizable terminal vinyl groups

Eleven N-substituted carbazoles (CZ) with terminal vinyl groups were synthesized by five sequences of reaction: N-(p-vinylbenzyl)- and N-β-(vinyloxyethyl)CZ by N-alkylations of potassium CZ with corresponding chlorides; N-(β-acryloyloxyethyl)CZ by the esterification of N-(β-hydroxyethyl)CZ with acryloyl chloride; N-acrylamido-or methacryl-amido-methyl CZ from N-hydroxymethyl CZ and acryl- or methacrylamide; N-(3-acryloyl- or methacryloyl-oxy-2-hydroxypropyl)CZ and N-[3-(p- or m-vinylanilino)-2-hydroxypropyl] CZ from N-(2,3-epoxypropyl)CZ and acrylic or methacrylic acid and p- or m-vinylaniline, respectively; and 2-[β-(N-carbazyl)propionyloxy]ethyl acrylate or methacrylate by the Michael addition of CZ to 2-hydroxyethyl acrylate or methacrylate, followed by esterifications. The vinyl polymers with pendant carbazyl groups more or less distant from the polymer backbones, prepared by conventional radical or cationic polymerization procedures, indicated charge-transfer spectra with 2,4,7-trinitrofluorenone (TNF) in tetrahydrofuran (THF) solutions that are spread over most of the visible range.     

The Rates of Diazomethane Formation from Methylnitrosoamides. The stability of diazomethane solutions towards aqueous alkalis

The rate of hydrolysis of N-methyl-N-nitrosoamides by aqueous alkalis varies greatly. Methylnitrosourea (1) is hydrolyzed rapidly by aqueous KOH-solutions at low temperatures to give a high yield of diazomethane. Under similar conditions, N,N′-dimethyl-N,N′-dinitroso-oxamide (3) is hydrolyzed more slowly, but also gives a good yield of diazomethane. N,N′-Dimethyl-N,N′-dinitrosoterephthal-amide (4) , and (N-methyl-N-nitroso)-4-amino-4-methyl-2-pentanone (5) are less easily hydrolyzed by aqueous KOH-solutions. N-Methyl-N-nitroso-p-toluenesulfonamide (2) was the least reactive out of those tested. The hydrolysis of diazomethane in toluene with aqueous bases follows first order kinetics. The hydrolysis rate is greatly influenced by the concentration and strength of the base and temperature.     

Competition of Dehydrochlorination and Dehydrobromination in Reactions of N,N,N-Trialkyl-N-(2,3-dibromo-3-chlorobutyl)ammonium Bromides with Alcoholic Solution of KOH

Reactions of N,N,N-trialkyl-N-(2,3-dibromo-3-chlorobutyl)ammonium bromides with alcoholic solution of KOH mainly follow the dehydrochlorination pathway, yielding N,N,N-trialkyl-N-(2,3-dibromo-2-butenyl)ammonium bromides as major products.     

Synthesis of isonipecotinoyl analogues of aminopterin and folic acid

The preparation of isonipecotinoyl analogues of aminopterin and methotrexate is described. Condensation of diethyl N-isonipecotinoyl-L-glutamate 4 with 2-amino-5-bromomethyl-3-cyanopyrazine 5 afforded diethyl N-(N-[(2-amino-3-cyanopyrazin-5-yl)methyl]isonipecotinoyl)-L-glutamate 6 . Cyclisation of 6 with guanidine followed by blocking group hydrolysis afforded N-([N-(2,4-diaminopteridin-6-yl)methyl]isonipecotinoyl)-L-glutamic acid 8 . Coupling of N-(2-amino-4(3H)ioxopteridin-6-yl]methyl)isonipecotinic acid 11 with diethyl L-glutamate gave diethyl N-[(N-[2-amino-4(3H)-oxopteridin-6-yl]methyl)isonipecotinoyl]-L-glutamate 12 . Blocking group hydrolysis afforded N-[(N-[2-amino-4(3H)-oxopteridin-6-yl]methyl)isonipecotinoyl]-L-glutamic acid 13 .     

Cyclocopolymerization of allyl‐acrylate quaternary ammonium salts with diallyldimethylammonium chloride

A series of copolymers of N,N‐dialkyl‐N‐2‐(methoxycarbonyl)allyl allyl ammonium chloride, N,N‐dialkyl‐N‐2‐(ethoxycarbonyl)allyl allyl ammonium chloride, and N,N‐dialkyl‐N‐2‐(t‐butoxycarbonyl)allyl allyl ammonium bromide with diallyldimethylammonium chloride (DADMAC) were prepared in water at 60 °C with 2,2′‐azo‐bis(2‐amidinopropane)dihydrochloride. A strong effect of ester substituents on cyclopolymerization was observed. The methyl and ethyl ester monomers showed high cyclization efficiencies during homopolymerizations and copolymerizations. Unexpectedly, the t‐butyl ester derivatives showed high crosslinking tendencies. Water‐soluble copolymers were obtained only with a decrease in the molar fraction of t‐butyl ester monomer below 30%. Relative reactivities of the allyl‐acrylate monomers in photopolymerizations were compared with the relative reactivity of DADMAC. Allyl‐acrylate monomers were much more reactive than DADMAC; the photopolymerization rate decreased in the following order: N,N‐morpholine‐N‐2‐(t‐butoxycarbonyl)allyl allyl ammonium bromide > N,N‐piperidyl‐N‐2‐(t‐butoxycarbonyl)allyl allyl ammonium bromide > N,N‐dibutyl‐N‐2‐(ethoxycarbonyl)allyl allyl ammonium chloride > N,N‐piperidyl‐N‐2‐(ethoxycarbonyl)allyl allyl ammonium chloride ∼ N,N‐morpholine‐N‐2‐(ethoxycarbonyl)allyl allyl ammonium chloride ∼ N,N‐piperidyl‐N‐2‐(methoxycarbonyl)allyl allyl ammonium chloride > N‐methyl‐N‐butyl‐N‐2‐(ethoxycarbonyl)allyl allyl ammonium chloride. Intrinsic viscosities of the polymers measured in 0.09 M NaCl ranged from 1.06 to 3.20 dL/g. The highest viscosities were obtained for copolymers of the t‐butyl ester monomers with piperidine and morpholine substituents. The copolymer of the t‐butyl ester with piperidine substituent and DADMAC was hydrolyzed in acid to give a polymer with zwitterionic character. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 640–649, 2001     

Synthesis, X-Ray Diffraction Data, and 1H and 13C NMR Spectra of N-(N-Arylsulfonylimidoyl)-1,4-benzoquinonimines Derived from N-Aroyl(acetyl)-1,4-benzoquinonimines

Oxidation of N-(N-arylsulfonylimidoyl)-4-aminophenols gave the corresponding N-[N-arylsulfonylimidoyl)-1,4-benzoquinonimines, derivatives of N-aroyl- and N-acetyl-1,4-benzoquinonimines. The structure of the products was studied by the X-ray diffraction method and ¹H and ¹³C NMR spectroscopy. N-(N-Arylsulfonylimidoyl)-1,4-benzoquinonimines were found to undergo fast (on the NMR time scale) Z E isomerization about the CÍN bond in the quinonimine fragment. N-(N-Arylsulfonylacetimidoyl)-1,4-benzoquinonimines in solution give rise to dynamic Z E-isomerization with respect to the CÍN bond in the N-arylsulfonylacetimidoyl fragment.     

Studies on the syntheses of azole derivatives. Part IX. Formation of 2,4-disubstituted δ2 -1,3,4-oxadiazolin-5-one and 4-substituted 1,2,4-triazolidin-3,5-dione derivatives by thermal reaetion of N-aryl-N-benzylearbamoyl azides

The structure of the novel produets, 2,4-ltis-(N-benzy1-4-nitroanilino)-Δ²-1,3,4-oxadiazolin-5-one (VII), 2-benzy1-1-(N-benzy1-4-chloroanilino)-4-(4-chlorophenyl)-1,2,4-triazolidin-3,5-dione (XIVa), and 2-benzy1-1-(N-benzylanilino)-4-pheny1-1,2,4-triazolidin-3,5-dione (XIVb), obtained upon thermal reaction of N-bcnzyl-N-(4-nitrophenyl)carbamoyl azide (la), N-benzyl-N-(4-chloro-phenyl)carbamoyl azide (Ib) and N-benzyl-N-phcnylcarbamoyl azide (le), respectively, were determined.     

Micellization of some amphiphilic quaternary ammonium chlorides

The micellization processes of N-dodecyl-N,N-dimethyl-N-[3-(β-methyl-β-nitrovinyl)-6-methoxybenzyl] ammonium chloride (I-A), N-dodecyl-N,N-dimethyl-N-benzylammonium chloride (I-B), N-dodecyl-N, N,N-trimethylammonium chloride (I-C), N-dodecyl-[3-(β-methyl-β-nitrovinyl)-4-methoxybenzyl] morpholinium chloride (IV-A), N-dodecyl-N-benzylmorpholinium chloride (IV-B), N-dodecyl-N-methylmorpholinium chloride (IV-C), and N-dodecyl-N-methylpiperidinium chloride (VI-C) were studied by means of the calorimetric titration method. The critical micelle concentrations and enthalpies of micellization were determined. It is suggested that the benzyl groups of I-B and IV-B and the nitrovinylbenzyl groups of I-A and IV-A behave as second chains during the micellization.     

Effect of Chemical Structure and Charge Distribution on Behavior of Polyzwitterions in Solution

Summary: The hydrodynamic and conformational properties of polyelectrolyte poly(N,N-diallyl-N,N-dimethylammonium chloride) and its corresponding polybetaine poly(2-diallyl(methyl)ammonio)acetate) molecules in aqueous solutions with various ionic strength and pH, were studied by viscometry, static and dynamic light scattering methods. It was established that a 1 M NaCl solution is a thermodynamically good solvent for poly(N,N-diallyl-N,N-dimethylammonium chloride). In water solutions conformation of poly(2-diallyl(methyl)ammonio)acetate) molecules corresponds to polymer coil under θ–conditions. An increase in the concentration of NaCl in water and 0.1M NaOH solutions from 0 to 1 mol/l brings about a sharp gain in the intrinsic viscosity of the polymer and in the hydrodynamic radius of molecules. This effect results from the decomposition of zwitterion pairs responsible for the compact conformation of polymer molecules in water and 0.1 M NaOH. The Kuhn segment length for poly(2-diallyl(methyl)ammonio)acetate) molecules A = 6.3 nm determined in water and in 0.1 M NaOH solutions practically coincided with A value 6.6 nm, received in 1 M NaCl and in 0.1 M NaOH/1M NaCl. For poly(N,N-diallyl-N,N-dimethylammonium chloride) molecules in 1 M NaCl solutions A = 3.9 nm.     

Synthesis and Structure of N,N-Dimethyldithiocarbamates of Tetraphenylantimony and Tetra-p-tolylantimony

Tetraphenylantimony N,N-dimethyldithiocarbamate (I) and tetra-p-tolylantimony N,N-dimethyldithiocarbamate (II) were synthesized via the reaction of tetraarylantimony chloride Ar₄SbCl (Ar = C₆H₅ or C₆H₄Me-4) with sodium N,N-dimethyldithiocarbamate in water. According to the X-ray diffraction data, the tetraarylantimony N,N-dimethyldithiocarbamate molecules have a distorted octahedral configuration. The Sb–S bond lengths are equal to 2.7158(5) Å, 2.7440(5) Å and 2.761(2) Å, 2.8002(2) Å for I and II, respectively.     

Studies on the syntheses of azole derivatives. Part IV. Novel Syntheses of 1-Benzylbenzimidazolines by Photolysis of N-Aryl-N-benzylcarbamoyl Azides [Studies on the Syntheses of Heterocyclic Compounds. Part CCCLXXVIII

Photolysis of N-benzyl-N-(4-substituted-phenyl)carbamoyl azides (Ia and Ib) afforded N-benzylidene-N′-benzylhydrazines (XIIa and XIIb) and the debenzylated benzimidazolines (XIIIa and XIIIb).     

Reaction of Phenylurea and N-Trimethylsilyl-N'-phenylurea with Vanadocene and N-Bromosuccinimide

Phenylurea and N-trimethylsilyl-N'-phenylurea react with vanadocene (Cp₂V) in toluene to give N-(⁵-cyclopentadienyl)vanadio-N'-phenylurea as a major product and Cp₂VN = C = O and aniline as byproducts. The reaction of N-trimethylsilyl-N'-phenylurea with N-bromosuccinimide in THF produces, instead of expected N-phenylureidosuccinimide and bromotrimethylsilane, succinimide and N-(p-bromophenyl)-N-trimethylsilylurea which hydrolyzes to form (p-bromophenyl)urea.     

Synthese und Struktur von N,N,N‴,N‴‐Tetraisobutyl‐N′,N″‐isophthaloylbis(thioharnstoff) und Dimethanol‐bis(N,N,N‴,N‴‐tetraisobutyl‐N′,N″‐isophthaloylbis(thioureato))dicobalt(II)

Synthesis and Structure of N,N,N?,N?‐Tetraisobutyl‐N′,N″‐isophthaloylbis(thiourea) and Dimethanol‐bis(N,N,N?,N?‐tetraisobutyl‐N′,N″‐isophthaloylbis(thioureato))dicobalt(II) The synthesis and the crystal structure of the ligand N,N,N?,N?‐tetraisobutyl‐N′,N″‐isophthaloylbis(thiourea) and its Co^II‐complex are reported. The ligand co‐ordinates quadridentately forming a di‐bischelate. The donor atoms O and S are arranged in cis‐position around the central Co^II ions. In addition the co‐ordination geometry is determined by methanol molecules resulting in the co‐ordination number five. The complex crystallizes in the space group P1 (Z = 1) with two additional methanol molecules per formula unit. The free ligand crystallizes in the space group P1 (Z = 2) with one methanol molecule per formula unit. It shows the typical keto form of N‐acylthioureas with a protonated central N atom. The structures of both acylthiourea fragments come close to E,Z′‐configurations.     

Three gemini cationic surfactants as biodegradable corrosion inhibitors for carbon steel in HCl solution

Three gemini cationic surfactants with different hydrophobic spacer chain lengths were synthesized and characterized. The inhibition effect of N,N′-bis(2-hydroxyethyl)-N,N′-dimethyl-N,N′-bis(2-(tetradecanoyloxy)ethyl)ethane-1,2-diaminium bromide (G-2); N,N′-bis(2-hydroxyethyl)-N,N′-dimethyl-N,N′-bis(2-(tetradecanoyloxy)ethyl) hexane-1,6-diaminium bromide (G-6); and N,N′-bis(2-hydroxyethyl)-N,N′-dimethyl-N,N′-bis (2-(tetradecanoyloxy) ethyl) dodecane-1,12-diaminium bromide (G-12) on the corrosion of carbon steel in 1.0 M HCl solution at 25–60 °C was studied by weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy. The results show that the synthesized inhibitors are effective inhibitors even at very low concentration, and the adsorption on the carbon steel surface obeys the Langmuir adsorption isotherm. Potentiodynamic polarization curves reveal that the synthesized inhibitors behave as a mixed-type inhibitor. Adsorption of used inhibitors led to a reduction in the double layer capacitance and an increase in the charge transfer resistance. Thermodynamic parameters have been obtained by adsorption theory. Surface activity and corrosion inhibition relationship were discussed. The biodegradability of the synthesized surfactants showed their readily biodegradation in the open environment and were considered as environmentally friendly corrosion inhibitors.

     

Effect of the Structure of Oxypropylated Hydroxyl-Containing Molecules on Glycolysis of Foamed Polyurethane

The activity of a polyether derived from ethylene and propylene oxides (Laprol 5003) and of N,N,N',N'-tetra(hydroxypropyl)ethylenediamine (Lapramol 294) in glycolytic degradation of elastic foamed polyurethane was studied.     

Oxidation of N-(1-Hydroxypolychloroethyl)sulfonamides

N-(2,2,2-Trichloro-1-hydroxyethyl)- and N-(2,2-dichloro-1-hydroxy-2-phenylethyl)arenesulfonamides are oxidized with chromium(VI) oxide to give, respectively, N-(arylsulfonyl)trichloroacetamides and N-(arylsulfonyl)dichloro(phenyl)acetamides. Under analogous conditions N-(2,2,2-trichloro-1-hydroxyethyl)trifluoromethanesulfonamide is converted into 1,1,1-trichloro-2,2-bis(trifluoromethylsulfonylamino)ethane.