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1.
A. N. Chekhlov 《Journal of Structural Chemistry》2004,45(4):724-728
The crystal structure of 1-(2-pyridiniomethyl)-2,4-bis(phenylsulfonyl)benzene bromide, (C24H20NO4S2)+. Br– (I) has been investigated by X-ray diffraction (XRD)analysis. The triclinic structure of I (space group P1, a = 7.863 , b = 8.350 , c = 9.043 , = 94.00°, = 97.81°, = 104.62°, Z = 1) was solved by direct methods and refined by full-matrix least-squares analysis in an anisotropic approximation to R = 0.048 for all 4570 reflections collected (CAD-4 automatic diffractometer, CuK
). The geometrical parameters of the organic cation were determined with a sufficient degree of accuracy. The crystal structure of I involves a very strong interionic hydrogen bond N+-HBr–.Original Russian Text Copyright © 2004 by A. N. ChekhlovTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 4, pp. 759–763, July–August, 2004.This revised version was published online in April 2005 with a corrected cover date. 相似文献
2.
Henryk Piekarski Katarzyna Łudzik Michał Wasiak 《Journal of Thermal Analysis and Calorimetry》2011,104(2):765-770
The critical micelle concentrations of gemini surfactants having different spacer chain lengths 8-7-8 and 8-8-8 in aqueous
solutions have been determined by calorimetric and densimetric methods within a wide temperature range. The isothermal volume
change upon micellisation of the title surfactants has been obtained from density measurements using pseudo-phase model. Predicted
values for apparent molar volume of the surfactant at the critical micellisation concentration (c.m.c.) agree very well with
infinite dilution volumes calculated from additivity method. It has been shown that the inflection point in the curves of
the dependence of volume expansion coefficient on molality can be used to determine the value of c.m.c. similar as the second
one of the two maxima which are observed on the concentration function of apparent molar heat capacity. The experimental determined
values of c.m.c. have been compared with the values presented in the literature data for 8-s-8 gemini surfactants. 相似文献
3.
Previously unknown E isomers of azomethines (Schiff bases) were synthesized from vanillal and vanillin esters by their reaction with cyclohexylamine. 相似文献
4.
Summary. Treatment of meso-tetra(tert-butyl)porphyrin with sulfuric acid/n-butanol affords a mixture of porphyrin and mono-tert-butylporphyrin in relatively high yield. 相似文献
5.
O. G. Strukov V. B. Kondrat’ev Z. V. Vlasova V. A. Petrunin 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2017,91(1):100-105
Conformers of the biologically active compounds CH3P(O)(OR)(SCH2CH2NR 2 ′ ), where (I) R = i-C4H9, R′ = C2H5 and (II) R = C2H5, R′ = i-C3H7, are calculated within the AM1 level of theory. The elongated and twisted forms with maximum and minimum distances between a nitrogen atom and those of a phosphorus tetrahedron, respectively, and bearing a syn and anti oriented alkoxy group relative to a phosphoryl oxygen, are studied. It is found that the differences between the energy, electronic, and geometric parameters of these forms are apparent in differences between their properties, e.g., the ability to participate in complexation and protonation, reactions that to some extent simulate the interaction between a substance and a biological object. 相似文献
6.
A number of (Z)-N,N-dialkyl- and (Z)-N-acyl-N-alkyl-O-methylnicotinamide oximes was synthesized. Their configuration was confirmed by the NOESY experiment. Evaluation of fungicidal
activity of compounds obtained was performed. 相似文献
7.
8.
D. A. Köse G. Gökçe S. Gökçe İ. Uzun 《Journal of Thermal Analysis and Calorimetry》2009,95(1):247-251
Three novel mixed ligand complexes of Ni(II), Zn(II) and Cd(II) with p-chlorobenzote and N,N-diethylnicotinamide were synthesised and characterized on the basis of elemental analysis, FTIR spectroscopic
analysis, solid state UV-Vis spectrometric and magnetic susceptibility data. The thermal behavior of the complexes was studied
by simultaneous TG-DTA methods in static air atmosphere and the mass spectra data were recorded.
According to microanalytical results, formulas of complexes are C34H40N4O8ClNi, C34H40N4O8ClZn and C34H44N4O10ClCd. The complexes contain two moles of coordination waters, two moles p-chlorobenzoate and two mole N,N-diethylnicotinamide (dena) ligands per formula unit. In these complexes, the p-chlorobenzoate and N,N-diethylnicotinamide behave as monodentate ligand through acidic oxygen and nitrogen of pyridine ring.
The decomposition pathways and the stability of the complexes are interpreted in the terms of the structural data. The final
decomposition products were found to be as metal oxides. 相似文献
9.
Victor V. Dotsenko Sergey G. Krivokolysko Victor P. Litvinov 《Monatshefte für Chemie / Chemical Monthly》2008,139(6):657-661
Morpholinium 3-cyano-4-methyl-6-oxo-1,6-dihydropyridine-2-thiolate upon treatment with primary amines and a formaldehyde excess
under mild conditions produces bis(pyrido[2,1-b][1,3,5]thiadiazin-7-yl)methane derivatives in good yields (67–87%).
Correspondence: Victor V. Dotsenko, State Enterprise “Luganskstandartmetrology”, 91021 Lugansk, Ukraine. 相似文献
10.
N. A. Ivanova Z. R. Valiullina O. V. Shitikova L. V. Spirikhin M. S. Miftakhov 《Russian Journal of Organic Chemistry》2008,44(3):335-339
(2S,3S,4S)-2,3-O-Isopropylidene-4-(methoxycarbonylmethyl)cyclopentan-1-one was synthesized starting from D-ribose through methyl (Z)-3-(5-acetyl-2,2-acetoxyacetyl-2,2-dimethyl-1,3-dioxolan-4-yl)prop-2-enoate which was subjected to cyclization in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene, followed by decarboxylation. 相似文献
11.
12.
Chemical and electrochemical syntheses of the zinc(II) and cadmium(II) complexes with the tetradentate Schiff base (H2L), the condensation product of 2-N-tosylaminobenzaldehyde with diaminodipropylamine, are carried out. The structures, compositions, and properties of the synthesized metal complexes are studied by elemental analyses, IR spectroscopy, 1H NMR, UV spectroscopy, X-ray absorption spectroscopy, and quantum-chemical calculations. The structure of the cadmium(II) complex is determined by X-ray diffraction analysis (CIF file CCDC no. 1446393). The cadmium(II) and zinc(II) complexes exhibit luminescence in a CH2Cl2 solution in the blue spectral range (λPL = 425–428 nm) with the photoluminescence quantum yields ? = 0.20 and 0.75, respectively. 相似文献
13.
Manish G. Yadav Monali R. Kavadia Rajeshkumar N. Vadgama Annamma A. Odaneth Arvind M. Lali 《Applied biochemistry and biotechnology》2018,184(4):1168-1186
l-ascorbyl palmitate (ASP) is an oil-soluble derivative of ascorbic acid which is used extensively in food, cosmetics industry, and medical hygiene. Enzymatic synthesis of ascorbyl palmitate in tert-butyl alcohol was carried out using indigenously immobilized lipase preparation PyCal with ascorbic acid and palmitic acid as starting material. The developed batch process under optimized reaction conditions resulted in conversion of 90% with relatively shorter reaction time of 6 h. Continuous process in packed bed reactor gave conversion of 50% with space time yield of 15.46 g/L/h which was found to be higher than the reported literature on enzymatic synthesis of ascorbyl palmitate. The immobilized lipase used in the present work showed good reusability. Characterization of formed ascorbyl palmitate was carried out by FTIR, MS/MS, H1-NMR, and C13-NMR. The enzymatic process resulted in selective synthesis of 6-O-l-ascorbyl palmitate with purity of 98.6% and no side product formation. The use of underivatized starting materials, high space time yield of 15.46 g L?1 h?1, high recyclability of catalyst, and no by-product formation make the overall process highly efficient and clean in terms of energy consumption and waste generation, respectively. The optimized reaction parameters for ascorbyl palmitate synthesis in the present study can be used as a useful reference for industrial synthesis of fatty acid esters of ascorbic acid by enzymatic route. 相似文献
14.
P. S. Vijayanand J. Vivekanandan A. Jeeva R. Arun Prasath 《Polymer Science Series B》2016,58(5):580-586
A new series of copolymers of poly(m-toluidine-co-m-aminoacetophenone) were synthesized by the chemical oxidative method in acid medium. The copolymers were characterized by UV–Vis and FTIR spectroscopy. X-ray diffraction analysis revealed the partial crystalline nature of copolymer. The morphological study by SEM analysis indicated that the surface of the copolymer had the granular structure of agglomerated morphology with average particle size of 200 nm. The conductivity of the copolymers ranged from 2 × 10–4 to 3.3 × 10–8 S/cm and the conductivity decreased with the increase of comonomer concentration. The resultant copolymers showed an enhanced solubility and an improved processability when compared with pure polyaniline. 相似文献
15.
S. Vidhisha Kotha Laxma Reddy K. Ashwini Kumar Yata Praveen Kumar S. Satyanarayana 《Transition Metal Chemistry》2010,35(8):1027-1034
This article describes the synthesis of a polypyridyl ligand, namely 2-(2, 5-dimethoxyphenyl)-1H-imidazo[4,5-f]1,10-phenanthroline (DMPIP) and its Ru(II) complexes, namely [Ru(bipy)2DMPIP]2+ (1), [Ru(dmb)2DMPIP]2+ (2) and [Ru(phen)2DMPIP]2+ (3) ((bipy = 2,2′-bipyridine, dmb = 4,4′-dimethyl-2,2′-bipyridine, phen = 1,10-phenanthroline). The complexes were characterized
by elemental analysis, plus IR, 1H-NMR and 13C [1H]-NMR spectra. The interactions of the complexes with calf thymus DNA were investigated. The results indicate that the three
complexes can intercalate into DNA. Under irradiation at 365 nm, all three complexes promote the photocleavage of plasmid
pBR 322 DNA. Inhibitor studies suggest that singlet oxygen plays a significant role in the cleavage mechanism for the complexes. 相似文献
16.
The effect of a spatially-hindered phenol, namely sodium 1-N-acetylamino-1-carboxy-2-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, on the functionality of mitochondria of rat liver was studied. Stress impact caused a 3 to 4-fold increase in the fluorescence intensity of the products of lipid peroxidation (LPO) in the membranes of these organelles. The preparation reduced the intensity of LPO to the control level, which was conductive to maintaining high functional activity of the mitochondria. Prevention of mitochondrial dysfunction was probably associated with an increase in the resistance of animals to stress factors. 相似文献
17.
Chiral dialkyl- and tetraalkylglycolurils have been obtained using chiral (S)-(+)- and (R)-(-)-1-sec-butyl-3-methylurea as starting materials. The diastereomer (S)-(+)-2,6-di-sec-butyl-4,8-dimethyl-2,4,6,8-tetraazabicyclo[3.3.0]-octane-3,7-dione was separated into stereoisomers, for the higher melting of which the absolute configuration was determined as (S,S,S,S) by X-ray structural analysis. 相似文献
18.
Ju-Lan Zeng Sai-Bo Yu Bo Tong Li-Xian Sun Zhi-Cheng Tan Zhong Cao Dao-Wu Yang Jing-Nan Zhang 《Journal of Thermal Analysis and Calorimetry》2011,103(3):1087-1093
An N-tert-butyloxycarbonylated organic synthesis intermediate, (S)-tert-butyl 1-phenylethylcarbamate, was prepared and investigated by means of differential scanning calorimetry (DSC) and thermogravimetry
(TG). The molar heat capacities of (S)-tert-butyl 1-phenylethylcarbamate were precisely determined by means of adiabatic calorimetry over the temperature range of 80-380 K.
There was a solid–liquid phase transition exhibited during the heating process with the melting point of 359.53 K. The molar
enthalpy and entropy of this transition were determined to be 29.73 kJ mol−1 and 82.68 J K−1 mol−1 based on the experimental C
p–T curve, respectively. The thermodynamic functions, [HT0 - H298.150 H_{T}^{0} - H_{298.15}^{0} ] and [ST0 - S298.150 S_{T}^{0} - S_{298.15}^{0} ], were calculated from the heat capacity data in the temperature range of 80–380 K with an interval of 5 K. TG experiment
showed that the pyrolysis of the compound was started at the temperature of 385 K and terminated at 510 K within one step. 相似文献
19.
A new type of hexane-soluble polymeric surfactant based on poly(4-tert-butoxystyrene) (P
t
BSt) was prepared by the nitroxide-mediated living radical polymerization, and their self-assemblies in hexane were explored.
Polystyrene-block-P
t
BSt diblock copolymers with six different P
t
BSt block lengths were obtained by the sequential living radical polymerization of styrene followed by 4-tert-butoxystyrene using 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl as the mediator; Mn(P
t
BSt block) = 13,500, 21,700, 26,600, 47,500, 91,300, and 108,000 at the constant length of the PSt block (Mn = 12,900). Dynamic
light-scattering studies demonstrated that the copolymers self-assembled into monodispersed spherical micelles in hexane.
The hydrodynamic diameter of the micelles increased with an increase in the P
t
BSt block length. The micellar size also increased as the copolymer concentration increased. However, the size decreased as
a result of the increasing temperature due to a decrease in the aggregation number. The 1H NMR analysis confirmed that the copolymers formed micelles with PSt cores. 相似文献
20.
I. N. Stan’kov A. A. Sergeeva V. B. Sitnikov O. T. Morozova I. D. Derevyagina S. N. Mylova V. M. Shchukin 《Journal of Analytical Chemistry》2007,62(6):564-570
A procedure was proposed for the gas-chromatographic determination of trace O-isobutyl-S-2-(N,N-diethylamino)ethyl ester of methylthiophosphonic acid (mixed ester, ME) in burning products formed after the detoxication of elements in building constructions, personal protection equipment, waste degassing solutions, and other production wastes (slime) at a level of (1.0–10.0) × 10?8 mg/g. The procedure is based on the extraction of ME from an analyzed material with a mixture of aqueous solutions of monoethanolamine and NaOH, its back extraction to hexane, the evaporation of the hexane layer (with the addition of HCl) to dryness, the transformation of ME into methyl ester of O-isobutylmethylphosphonic acid with the use of methanol in the presence of AgNO3, and the chromatography of the derivative on an open tubular column with the chemically modified HP-INN OWax stationary phase with the use of a flame-photometric detector. 相似文献