Synthesis and molecular structure oftrans-2,6-dimethallyl-1,1-dimethyl-1,2,3,6-tetrahydropyridinium iodide

The structure oftrans-2,6-dimethallyl-1,1-dimethyl-1,2,3,6-tetrahydropyridinium iodide was established by X-ray structural analysis. The corresponding base was synthesized by reductive diallylation of pyridine with trimethallylborane in the presence of 2-propanol. Deceased in 1995. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1413–1415, July, 1997.     

Synthesis and properties of long-chain quaternary ammonium hydroxides

A series of long-chain quaternary ammonium hydroxides were synthesized from tertiary amines and confirmed by ~1H NMR and FTIR.Surface properties and pH of these surfactants were investigated.The critical micelle concentrations(CMC) of the synthesized quaternary ammonium hydroxides are lower than the conventional quaternary ammonium surfactants.The micelles shapes of these long-chain quaternary ammonium hydroxides in aqueous solution are spherical at a concentration of 0.1 mol/L.The pH values of the synthesized quaternary ammonium hydroxides are 12.25-12.51.     

An NMR study of quaternary ammonium salts of 5,7-dimethyl-1,3-diazaadamantan-6-one

The temperature dependence of the ¹H NMR spectra of quaternary ammonium salts of 5,7-dimethyl-1,3-diazaadamantan-6-one in D₂O was examined. The molar ratio of the ketone and hydrate forms was determined.     

Crystal and molecular structure of two new Schiff bases: Paeonol-ethylenediamine and paeonol-1,3-propylenediamine

Two new Schiff bases were prepared by the condensation reaction of paeonol with ethylenediamine (for compound 1) and 1,3-propylenediamine (for compound 2). The compounds were studied with single crystal X-ray diffraction method. Compound 1 is monoclinic, space group P2₁/c, a = 10.956(15) Å, b = 6.767(10) Å, c = 12.494(18) Å; β = 104.66(2)°, V = 896(2) ų, Z = 2. Compound 2 is triclinic, space group P-1, a = 6.878(2) Å, b = 12.141(4) Å, c = 12.414(4) Å; α = 101.023(6)°, β = 103.415(6)°, γ = 102.337(6)°, V = 952.8(6) ų, Z = 2. The molecular structures of 1 and 2 are similar; the molecule being centrosymmetric in 1 but asymmetric in 2.     

The molecular structure of 1,1-dimethyl-3-phenylpyrazolium-5-oxide

The molecular structure of 1,1-dimethyl-3-phenylpyrazolium-5-oxide has been determined by a single crystal x-ray diffraction study. The crystals are monoclinic, space group P2₁/a, with unit cell dimensions a = 12.630 (5) Å, b = 6.644 (1) Å, c = 12.486 (5) Å, β = 99.17 (2)°. The final R value was 0.049 for 2930 reflections. The bond lengths and angles suggest that a significant contribution to the structure is made by a resonance form in which one of the ring bonds does not exist. No close intermolecular approaches were found.     

Synthesis,molecular structure and optical properties of glycidyl derivatives of quercetin

Structural Chemistry - Synthesis of glycidyl ethers of quercetin and studies of their structure and spectral properties have been carried out. Using FTIR spectroscopy, 1H and HSQC NMR spectroscopy,...     

三烷基季铵盐阳离子表面活性剂的合成与性能测定

用柠檬酸、十二烷基二甲基叔胺与环氧氯丙烷反应合成了柠檬酸三酯三烷基季铵盐阳离子表面活性剂。实验结果表明,在异丙醇溶剂中,反应体系在80℃,反应时间12h,产物的收率为91.5%。用红外光谱、元素分析、高效液相色谱对其结构进行了表征,通过测定其临界胶束浓度、Krafft点及泡沫性能,对产物表面活性进行了分析。     

Synthesis and spectral luminescence properties of stilbene derivatives containing 2-pyrazolinyl and 1,3-oxazolyl groupings

A number of trans-stilbene derivatives containing 2-pyrazolinyl and 1,3-oxazolyl groupings were synthesized by PO olefination from 1-(4-formylphenyl)-3-aryl-5-phenyl-2-pyrazolines and 2-(4-bromomethylphenyl)-5-phenyl-1,3-oxazole. The products fluoresce intensely in the green or yellow-green region (quantum yields 0.4–0.57). The intense long-wave absorption band of the investigated compounds is due to an electron transition that is localized primarily in the stilbene fragment of their molecules that includes, as a substituent, the amine nitrogen atom of the pyrazoline ring; the less intense shortwave band corresponds to localization of the electronic excitation in the hydrazone grouping.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 656–661, May, 1977.     

Synthesis, structure, and spectral luminescent properties of novel 1,2,4-triazole derivatives containing benzthiazole group

Novel derivatives of 1,2,4-triazol with benzthiazole fragment have been prepared, including Cu(II) and Be complexes. Their structure and spectral luminescent properties have been investigated. With ohydroxyphenylbenzthiazolyl-1,2,4-triazole as an example, the density functional theory has been applied to find the stable conformers with different structures of coordination nodes, stabilized by intramolecular hydrogen bonds between hydroxyl group hydrogen and either triazole of benzthiazole nitrogen.     

Synthesis,structure, spectral properties,and electrochemistry of bis(crown ether) containing 1,3-distyrylbenzenes

The reaction of tetraethyl [1,3-phenylenedi(methylene)]bis(phosphonate) with formyl derivatives of benzocrown-ethers or formyl derivatives of o-dimethoxybenzene lead to high yield formation of the respectful bis(crown ether) containing 1,3-distyrylbenzenes or tetramethoxy-substituted 1,3-distyrenebenzenes. NMR spectra and quantum-chemical calculations showed the prevalence of unsymmetrical syn/anti,(syn,anti),syn/anti-conformations in 1,3-distyrylbenzenes. 1,3-Distyrylbenzenes absorb in shorter wavelength spectral region and have a weaker fluorescence than 1,4-distyrylbenzenes. The difficulty in the electrochemical reduction of 1,3-distyrylbenzenes comparing with 1,4-distyrylbenzenes is due to a less effective conjugation system in the metaderivatives.     

Effect of the nature of quaternary ammonium surfactants on the structure and properties of mesoporous molecular sieves

The influence of the nature of surfactant cations (dodecyltrimethylammonium bromide and tosylate and ethonium chloride) on the structure and adsorbent properties of mesoporous molecular sieves has been studied. The possibility of spatial self-organization of silica-surfactant systems without hydrothermal treatment has been observed. The influence of the surfactant counterions on the structure formation process has also been noted. L. V. Pisarzhevskii Institute of Physical Chemistry, Ukrainian Academy of Sciences, Ukraine, 252039 Kiev, Science Prosp., 31. Translated from Teoreticheskiya i éksperimental’naya Khimii, Vol. 33, No. 1, pp. 53–57, January–February, 1997.     

Synthesis and properties of new polymeric surfactant with quaternary ammonium salt

The polymeric surfactant with quaternary ammonium salt (PQ) was synthesized by cationic ring-open polymerization using boron trifluoride diethyletherate as cationic catalyst. The chemical structure and aggregation behavior of PQ were studied by ¹H NMR, surface tension, static light scattering, dynamic laser light scattering, electrical conductivity, and fluorescence measurement. The results show the surface tension (γ_cmc) and critical micelle concentration (cmc) of PQ decrease with increasing of sodium chloride concentration. The cmc and γ_cmc values of PQ measured by electrical conductivity and fluorescence measurements mainly identify with that obtained by surface tension measurements. The thermodynamic parameters (DG_m⁰ \Delta G_m^0 ,DH_m⁰ \Delta H_m^0 ,DS_m⁰ \Delta S_m^0 ) from electrical conductivity indicated that the micellization of PQ was mainly the process of entropy-driven. In addition, the results from the viscosity stability between hydrolyzed polyacrylamide (HPAM) and PQ showed that the viscosities of mixed system for HPAM and PQ are higher than the viscosity of HPAM.     

Synthesis and properties of quaternary ammonium Gemini surfactants with hydroxyl groups

The article describes synthesis of four hydroxyethyl alkylene–double alkyl bromide through substitution of nucleophilic d iethanolamine, 1-bromododecane, and 1,4-dibromobutane. The structure of the new hydroxyl cationic surfactant (HDCS) was characterized by ¹H NMR and FTIR spectra. The aqueous solution of HDCS showed critical micelle concentration, i.e., 5.6 × 10^?2 mM, and could reduce oil/water interfacial tension to 3.28 × 10^?3 mN m^?1. The surface tension measurements provided a series of parameters, including critical micelle concentration (CMC), surface tension at the CMC (γ_CMC), adsorption efficiency (pC₂₀), and effectiveness of surface tension reduction (Π_CMC). In addition, maximum surface excess concentration (Г_max) and minimum surface area/molecule (A_min) at the air/water interface were obtained by the Gibbs adsorption isotherm. The influence of inorganic salts (sodium chloride, calcium chloride) and organic salts (sodium benzoate) on the surface tension of HDCS in aqueous solution was investigated. For wettability alteration measurement, contact angle measurement as a quantitative method was utilized. Meanwhile, foam ability, foam stability, and emulsifying property of the synthesized surfactant were also examined at different concentration. HDCS also had excellent viscosity property.     

Electron impact mass spectral fragmentation of chiral bisbenzoxazole,bisbenzothiazole and biscarbamide derivatives of 2,2-dimethyl-1,3-dioxolane

The mass spectrometric fragmentation behaviour of five pairs of (R,R)- and (S,S)-4,5-bis(benzoxazol-2-yl)-2,2-dimethyl-1,3-dioxolane derivatives, one pair of (R,R)- and (S,S)-4,5-bis(benzothiazol-2-yl)-2,2-dimethyl-1,3-dioxolanes, and three pairs of (R,R)- and (S,S)-N,N'-bis(2-hydroxyaryl)-2,2-dimethyl-1,3-dioxolane-4,5-dicarbamides, all important compounds for asymmetric catalysis (P. Jiao et al., Tetrahedron Asymmetry 2001; 12: 3081), has been studied with the aid of mass-analyzed ion kinetic energy spectrometry and accurate mass measurements under electron impact ionization conditions. The spectral observations have been rationalized in terms of fragment ion structures and fragmentation mechanisms that will provide an aid to spectral interpretation for new compounds of this type.     

Synthesis, molecular structure, conformational analysis, and chemical properties of silicon-containing derivatives of quinolizidine

A silicon analog of quinolizidine 3,3,7,7-tetramethylhexahydro-1H-[1,4,2]oxazasilino[4,5-d][1,4,2]oxazasilin-9a-yl)methanol 3 was synthesized. X-ray diffraction analysis confirmed the trans configuration and low temperature NMR spectroscopy both the flexibility (barrier of interconversion 5.8 kcal mol(-1)) and the conformational equilibrium (chair-chair and chair-twist conformers) of the compound. The relative stability of the different isomers/conformers of 3 was calculated also at the MP2/6-311G(d,p) level of theory. Intra- and intermolecular hydrogen bonding in 3 and the appropriate equilibrium between free and self-associated molecules was studied in solvents of different polarity. Both the N-methyl quaternary ammonium salt and the O-trimethylsilyl derivative of 3 could be obtained and their structure determined.     

Synthesis,structure, and spectral properties of some bioxazoles

Syntheses of systems containing two oxazole rings [2-phenyl-, 2-(2-furyl)-, and 2-(2-thienyl)-2,5-bioxazoles, and 2,2-(2,5-furylene)bisoxazole] from aldehydes obtained by formylating 2-phenyl-, 2-(2-furyl)-, and 2-(2-thienyl)oxazole have been developed. Terephthalate and thiophen-2,5-dicarboxylate esters have been used to obtain 2,2-(1,4-phenylene)- and 2,2-(2,5-thienylene)bisoxazoles. The PMR, UV, and luminescence spectra of these systems have been examined, and quantum chemical calculations carried out in the PPP approximation.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 826–836, June, 1986.     

溴化苄基取代吡啶类季铵盐的制备和抗菌性能

抗菌材料和抗菌制品的研究与应用一直是世界各国研究的重要课题~([1-3]),其中有机抗菌剂占据主要地位.季铵盐是研究比较多的一类有机抗菌剂,它们表现出良好的物理性质,如胶束浓度低,黏弹性好和溶解性强~([4]),同时此类抗菌剂具有强效的抗菌作用~([5]),引起了人们的极大兴趣.季铵盐广泛应用于医药、卫生、食品、饲料工业、农业、纺织、塑料、橡胶、造纸、水处理、油田开采、涂料、日常生活等多种领域~([6-10]).