2-[2-(2,3-Dihydrobenzimidazolylidene)]- and 2-[2-(2,3-Dihydropyrido[2,3-d]imidazolylidene)]-5,5-dimethyl-1,3-cyclohexanediones

The reaction of 2-aminocarbonyl-5,5-dimethyl-1,3-cyclohexanedione with 2,3-diaminopyridine, 1,2-phenylenediamine (and its 4-methyl, 4-nitro, 4-carboxy, and 4-benzoyl derivatives), and 3,3-diaminobenzidine gave the corresponding 2-[2-(2,3-dihydrobenzimidazolylidene)]- and 2-[2-(2,3-dihydropyrido[2,3-d]imidazolylidene)]-5,5-dimethyl-1,3-cyclohexanediones. Their structure was confirmed by ¹H NMR spectroscopic data and X-ray analysis.     

Synthesis of (2-hydroxy-5-nitrophenyl)di[1-(2-hydroxynaphthyl)]methane and 12-[1-(2-hydroxynaphthyl)]-10-nitro-12H-benzo[α]xanthene from of 5-nitrosalicylaldehyde derivatives and β-naphthol

The reaction of the morpholinal or anil of 5-nitrosalicylaldehyde with β-naphthol yielded (2-hydroxy-5-nitrophenyl)di[1-(2-hydroxynaphthyl)]methane. Condensation of the latter compound in boiling nitromethane gave 12-[1-(2-hydroxynaphthyl)]-10-nitro-12H-benzo[α]xanthene. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1336–1339, July, 1997.     

Reactions of 5-[3-(trifluoromethyl)-phenyl]furan-2-carbaldehyde

The Knoevenagel condensations of 5-[3-(trifluoromethyl)phenyl]furan-2-carbaldehyde with seven compounds containing an active methyl or methylene group have been studied. The compounds used were: methyl 2-cyanoacetate, malononitrile, 2-furylacetonitrile, acetophenone, 2-thioxo-1,3-thiazolidin-4-one (rhodanine), 5,5-dimethylcyclohexane-1,3-dione (dimedone), and methyl 2-azidoacetate. The effect of microwave irradiation on the condensation reactions was studied and compared with “’classical”’ conditions. Thermolysis of methyl 2-azido-3-{5-[3-(trifluoromethyl)phenyl]-2-furyl}propenoate afforded methyl 2-[3-(trifluoromethyl)phenyl)]-4H-furo[3,2-b]pyrrole-5-carboxylate. (2E)-3-{ 5-[3-(Trifluoromethyl)phenyl]-2-furyl}propenoic acid was converted to the corresponding azide, which was cyclized on heating into 2-[3-(trifluoromethyl)phenyl)]-4,5-dihydrofuro[3,2-c]pyridin-4-one. The latter after successive action of POCl₃ and NH₂NH₂-Pd/C gave 2-[3-(trifluoromethyl)-phenyl]furo[3,2-c]pyridine. Published in Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 825–831, June, 2006.     

2-[2-(6-Methylbenzothiazolyl)azo]-5-Diethylaminobenzoic acid as a new analytical reagent for the spectrophotometric determination of nickel

A new thiazolylazo chromogenic reagent, 2-[2-(6-methylbenzo-thiazoly)azo]-5-diethylaminobenzoic acid (6-Me-BTAEB), has been synthesized. Its chromogenic reaction with microamounts of nickel in the presence of sodium dodecylsulfate (SDS) has been thoroughly studied. 6-Me-BTAEB reacts with nickel(II) in weak acid medium containing appropriate amounts of SDS to form a blue-violet complex with high sensitivity, good selectivity and high stability. The composition is found to be 1:2 (nickel to 6-Me-BTAEB) and its absorption maximum is at 650 nm with an apparent molar absorptivity of 1.67 × 10⁵l mole^–1 cm^–1. Beer's law is obeyed over the range 0-0.4 g of nickel per ml. The proposed method has been applied to the direct determination of nickel in aluminium alloys, pure magnesium and low alloy steels at the 0.2–0.3% (w:w) level with satisfactory results.     

Spectral properties and inclusion of 3-(4'-dimethylaminophenyl)-1-(2-furanyl)prop-2-en-1-one in organized media of micellar solutions, beta-cyclodextrin and viscous medium

On the line of a previous work on the spectral properties of some of heteroaryl chalcone, the absorption and fluorescence emission spectral properties of 3-(4'-dimethylaminophenyl)-1-(2-furanyl)prop-2-en-1-one (DMAFP), have been investigated in organized media of aqueous micellar and beta-cyclodextrin (beta-CD) solutions. While the absorption spectra are less sensitive to the nature of the added surfactant or beta-CD, the characteristics of the intramolecular charge transfer (ICT) fluorescence are highly sensitive to the properties of the medium. The ICT maximum is strongly blue-shifted with a great enhancement in the fluorescence quantum yield on adding micellar or beta-CD. This indicates the solubilization of DMAFP in the micellar core and formation of an inclusion complex with beta-CD. The critical micelle concentrations (CMC) as well as the polarity of the micellar core of SDS, CTAB and TX-100 have been determined. The CMC values are in good agreement with the reported values while the polarity is lower indicating that DMAFP molecules are incorporated in the micellar core not at the micellar interface. The inclusion constants of binding of DMAFP in micellar or beta-CD have been also determined. The thermodynamic parameters of formation of DMAFP:CD inclusion complex have been calculated from the temperature dependence of the fluorescence spectra of the formed complex. The highly negative value of formation entropy (DeltaS=-98.0Jmol(-1)K(-1)) reflects the high restrictions imposed on the movement of both the host and included guest molecules which is consistent with the increase of the fluorescence yield and blue shift of the fluorescence maximum.     

Effect of type and concentration of surfactants on swelling behavior of poly[<Emphasis Type="Italic">N</Emphasis>-[3-(dimethylamino)propyl]methacrylamide-co- <Emphasis Type="Italic">N,N</Emphasis>-methylenebis(acrylamide)] hydrogels

A series of thermosensitive hydrogels were prepared from N-[3-(dimethylamino)propyl]methacrylamide (DMAPMA) monomer by using 11.6–17.8% (m/m) N,N-methylenebis(acrylamide) (MBAAm) as the crosslinker and comonomer in water. A kinetic study of the absorption determined the transport mechanism. The diffusion coefficients of these hydrogels were calculated for the Fickian mechanism. It was shown that the swelling behavior of the P(DMAPMA-co-MBAAm) hydrogels can be controlled by changing the amount of MBAAm. The swelling equilibrium of the P(DMAPMA-co-MBAAm) hydrogels was also investigated as a function of temperature in aqueous solutions of the anionic surfactant sodium dodecyl sulfate (SDS) and the cationic surfactant dodecyltrimethylammonium bromide (DTAB). In pure water, irrespective of the amount of MBAAm, the P(DMAPMA-co-MBAAm) hydrogels showed a discontinuous phase transition between 30 and 40 °C. However, the transition changed from discontinuous to continuous with the addition of surfactants, this is ascribed to the conversion of non-ionic P(DMAPMA-co-MBAAm) hydrogel into polyelectrolyte hydrogels due to binding of surfactants through the hydrophobic interaction. Additionally, the amount of free SDS and DTAB ions was measured at different temperatures by a conductometric method, it was found that the electric conductivity of the P(DMAPMA-co-MBAAm) – surfactant systems depended strongly on both the type and concentration of surfactant solutions.     

Resonance Rayleigh scattering spectra of ion-association nanoparticles of [Co(4-[(5-Chloro-2-pyridyl) azo]-1, 3-diaminobenzene)2]-sodium dodecyl benzene sulfonate system and its analytical application

In pH 1.8-3.0 Britton-Robinson (BR) buffer solution, cobalt (II) reacts with 4-[(5-Chloro-2-pyridyl) azo]-1, 3-diaminobenzene (5-Cl-PADAB, L) to form a cationic chelate [CoL₂]²⁺. When interacting with anionic surfactants (AS) such as sodium dodecyl benzene sulfonate (SDBS), sodium dodecyl sulfate (SDS) or sodium dodecyl sulfonate (SLS), the chelate can only react with SDBS to form ternary ion-association complexes ([CoL₂][SDBS]₂). By virtue of the extrusion action of water and Van der Waals force, the hydrophobic ion-association complexes draw close to each other and further aggregate to form {[CoL₂][SDBS]₂}_n nanoparticles with an average diameter of 30 nm. As a result, resonance Rayleigh scattering (RRS) is enhanced greatly and new RRS spectra appear. Under the same conditions, both SDS and SLS exhibit no similar reactions and do not result in obvious change of RRS. Therefore, SDBS can be determined selectively by RRS method in the presence of SDS or SLS. The wavelength of 516 nm was chosen as a detection wavelength, the linear range and the detection limit (3σ) are 0.05-6.0 μg mL⁻¹ and 0.015 μg mL⁻¹ for the determination of SDBS, respectively. The characteristics of RRS spectra of the [CoL₂]²⁺-SDBS system, the optimum conditions of the reaction and the influencing factors have been investigated. The effects of coexisting substances have been examined too, indicating a good selectivity of the method for the determination of SDBS. The method can be used for the determination of SDBS in waste water and river water samples, and the results are satisfactory compared with those of standard samples of SDBS. Based on the formation of {[CoL₂][SDBS]₂}_n nanoparticles, a sensitive, simple and rapid method has been developed for the determination of SDBS in environmental water samples using a RRS technique. Moreover, the reaction mechanism was discussed.     

Synthesis and Characterization of p—[Perfluoro—1—（2—fluorosulfonylethoxy）]ethylated Polystyrene

A new fluorinated polystyrene bearing a p-sulbstiuted perfluoro[1-(2-fluorosulfonylethoxy)]ethyl group was synthesized via one-electron oxidation of polystyrene by perfluoro[2-(2-fluorosulfonylethoxy)]propionyl peroxide at different peroxide to polystyrene molar ratios.The yield of perfluoroalkylation decreases with the increase of the reactant molar ratio.The modified polymer has been characterized by various techniques:the ring pefluoro[1-(2-fluorosulfonylethoxy)]ethylation has been proved by FT-IR and ^19FNMR;the X-ray photoelectron spectra(XPS) show the maximum binding energy of F18,O18,C18(two kinds of carbon atoms,namely C-H and C-F)and S2p,respectively; desulfonylation of the fluorinated polystyrene appearing at 217℃ has been found by its thermogravimetric analysis (TGA).The determinations of contact angle,refractive index and glass transition temperature of the modified polymer have disclosed that when the contact angle increases with the increase of the molar ratio,the refractive index and glass transition temperature decrease.The polydispersity values indicate that the degradation of the polymer chains did not occur during the reaction.     

钴(II)-2-(5-溴-2-吡啶偶氮)-5-二乙氨基酚体系共振瑞利散射法测定环境 水样中十二烷基苯磺酸钠

在pH 1.8～3.0的Britton-Robinson (BR)缓冲溶液中, 钴(II)与2-(5-溴-2-吡啶偶氮)-5-二乙氨基酚(5-Br-PADAP)(HL)反应形成紫红色螯合阳离子, 此时仅能引起吸收光谱的变化, 不能导致共振瑞利散射(RRS)的增强. 当钴(II)-5-Br-PADAP螯合阳离子与阴离子表面活性剂十二烷基苯磺酸钠(SDBS)、十二烷基磺酸钠(SLS)和十二烷基硫酸钠(SDS)作用时, 仅能与SDBS进一步反应形成三元离子缔合物并引起RRS的显著增强, 而不与SDS和SLS产生类似反应. 离子缔合物的RRS峰分别位于306, 370和650 nm处, 在一定范围内RRS增强(ΔI)与SDBS浓度成正比, 当用650 nm处测量时, 其检出限为0.043 μg&#8226;mL－1, 线性范围为0.14～6.0 μg&#8226;mL－1. 文中研究了反应产物的RRS光谱特征, 适宜的反应条件及分析化学性质, 据此发展了一种在一定量SDS和SLS等阴离子表面活性剂存在下选择性测定SDBS的新方法, 方法灵敏、简便、快速,用于天然水和污水中SDBS的测定, 获得满意结果. 文中还对反应机理进行了讨论.     

Reactions of 3-[N-chloroacetylamino-N-(4-nitrophenyl)]-2-formylindole with alkylamines

The reactions of 3-[N-chloracetylamino-N-(4-nitrophenyl)]-2-formylindole (1a) with 2-(N, N-dialkylamino)ethylamines afford complex condensation products 7b,c consisting of two similar but not identical diazepinoindole fragments. For the reaction of compound 1a with 3-(N,N-diethylamino)propylamine, the process occurs in a different manner, and the predominant product is 4-ethylaminopropyl-1-(4-nitrophenyl)-2-oxo-1,2,3,4,5,6-hexahydro[1,4]diazepino[6,5-b]indole hydrocloride (14). Two routes of these unexpected transformations were proposed. The structures of the synthesized products were proved by the ¹sH and ¹³C NMR, HMBC, and HSQC (direct proton-carbon correlation) spectra. Dedicated to Academician V. A. Tartakovsky on the occasion of his 75th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1536–1542, August, 2007.     

[SiZn(H2O)W11O39]6-在玻碳电极上的多层组装及电催化性能

采用循环伏安法研究一取代硅钨杂多酸在酸性水溶液中的电化学行为及pH的影响.制备了包含杂多酸[SiZn（H2O）W11O39]%6-（SiZnW11）和聚合物阳离子-聚二烯丙基二甲基氯化铵（PDDA）的多层膜修饰电极,研究了其电化学行为.逐层的循环伏安行为表明膜的增长均匀,峰电流随膜层数的增加而增加,与其在液中的氧化还原行为相比,多层膜中的SiZnW11显示出一些特殊的性质.对BrO3^-和NO2^-体系的还原具有良好的电催化性能.     

2-(5-取代苯氧甲基-1,3,4-噻二唑-2-亚胺基)-5-(取代苯基亚甲基)-4- 噻唑啉酮的合成

以2-氨基-5-取代苯氧甲基-1,3,4-噻二唑(1)为起始原料, 合成了中间体2-氯乙酰氨基-5-取代苯氧甲基-1,3,4-噻二唑)-2-乙酰亚胺(2)和2-(5-取代苯氧甲基-1,3,4-噻二唑-2-亚胺基)-4-噻唑啉酮(3), 化合物3进一步与取代苯甲醛发生类Knoevenagle缩合反应, 得到了一系列2-(5-取代苯氧甲基-1,3,4-噻二唑-2-亚胺基)-5-(取代苯基亚甲基)-4-噻唑啉酮类化合物4a～4p. 目标化合物4a～4p的结构经IR, ¹H NMR和元素分析确证.     

Surfactant tail length-dependent lipase activity profile in cationic water-in-oil microemulsions

The catalytic activity of Chromobacterium viscosum lipase (CV-lipase) was estimated across varying surfactant tail lengths (C-10-C-18) in water-in-oil (w/o) microemulsions of cationic surfactants containing four different hydroxyethyl-substituted head groups. An attempt to find a correlation, if any, between the activity of interfacially solubilized lipase and the varying surfactant tails was made for the first time in micellar enzymology. The second-order rate constant, k2, in lipase-catalyzed hydrolysis of p-nitrophenyl-n-hexanoate at pH 6.0 and 25 degrees C shows an improvement in enzyme activity (approximately 30-140%) across different head groups of amphiphiles with increasing tail lengths in varying solution compositions. Improvement of enzyme activity is prominent in ascending from C-10 to C-14/C-16, depending on the nature of polar head group. The hydrolytic activity of lipase in different surfactant (50 mM)/water/isooctane/n-hexanol with varying z= [alcohol]/[surfactant] (6.4 or 4.8) was amplified by 25-250% with increment in surfactant tail length in comparison with widely used cationic w/o microemulsions having solution compositions (z=16). As a notable outcome of this research, we found w/o microemulsions of 25 mM tetradecyltrimethylammonium bromide/water/isooctane/n-hexanol (z=8) producing the highest ever activity of lipase in any w/o microemulsions.     

Interaction of Ionic Surfactants with a Hydrophobic Modified Thermosensitive Polymer

The interactions of a hydrophobic modified thermosensitive polymer poly(N-isopropylacrylamide)-ran-poly(methacrylic acid)-ran-poly(octadecyl acrylate) with five ionic surfactants, namely, sodium dodecyl sulfate (SDS), dodecayltrimethylaminium bromide (DTAB), 1,2-bis(dodecyldimethylammonio)- hexane dibromide (12-6-12), 1-dodecanaminium, N,N′-[(1,4-dioxo-1,4-butanediyl) bis(oxy-2,1-ethanediyl)] bis[N,N-dimethyl-, bromide] (12-su-12), and dodecanaminium, N, N′-[[(2E)-1,4-dioxo-2-butene-1, 4-diyl]bis(o-xy-2,1ethanediy-l)] bis[N,N-dimethyl-, bromide] (12-fo-12) were investigated by the static-steady fluorescence methods using crystal violet and pyrene as the probes. It was found that the SDS interacted with the polymer driven by the hydrophobic interaction, while the cationic surfactants first entered the core of the polymer micelle through the hydrophobic interaction then the corona area of the polymer micelle through the hydrophobic and static electrical interactions. Measurements of the transmittances of the polymer/surfactants/PBS mixtures at different temperatures showed that the SDS suppressed the phase transition of the system, while additions of the cationic surfactants into the polymer induced the phase transitions of the polymer complex systems first, then suppressed them after the minimum values of the lower critical phase transition temperatures (LPTT) was reached. It was also found that increase of the MAA content in the polymer could broaden the LPTT range adjusted by the cationic surfactants.      

Synthesis and analytical properties of the polymerized surfactant pposa

A new low-polymer surfactant, poly(propylene oxide)--stearyldimethylammonium chloride (PPOSA) has been synthesized. It contains a polyglycol main chain and quaternary ammonium branched chains. Investigation of the surface-active properties of PPOSA showed that as a sensitizing and solubilizing reagent for spectrophotometric analysis it possesses some of the characteristics of both cationic and non-ionic surfactants. The surfactant shows a sensitizing effect superior or equal to that of classical surfactants commonly used in analytical chemistry. Use of PPOSA leads to development of some excellent micellar spectrophotometric procedures for determining trace metals.     

Synthesis of 3-[2-(1,3-butadienyl)]-1H-indoles en route to murrapanine analogue

A three-step procedure has been developed for the synthesis of 3-[2-(1,3-butadienyl)]-1H-indoles. TBAF was proved to be an effective reagent for dehydrobromination and carbomethoxy deprotection in one step to give 3-[2-(1,3-butadienyl)]-1H-indoles from the corresponding bromo-derivatives. Suitably substituted indolyl-1,3-butadiene has been successfully applied to prepare murrapanine analogue via Diels-Alder reaction.     

Synthesis and Crystal Structure of 1-（4-Fluorophenyl）-2-hexylthiobenzo[4,5]-furo[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidin-5（1H）-one

The crystal structure of the title compound 1-(4-fluorophenyl) -2-hexylthio-benzo [4,5]furo[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidin-5(1H) -one(C23H21FN4O2S,Mr = 436.5) has been prepared and determined by single-crystal X-ray diffraction. The crystal is of monoclinic,space group P21/n with a = 13.9854(3) ,b = 17.2678(4) ,c = 18.1828(5) ,β = 99.364(2) °,V = 4332.58(18) 3,Z = 4,Dc = 1.338,F(000) =1824,μ = 0.185 mm-1,MoKa radiation(λ = 0.71073) ,R = 0.0538 and wR = 0.1162 for 4728 observed reflections with I > 2σ(I) . X-ray diffraction analysis reveals the fused rings of benzo[4,5]furo[3,2-d]-1,2,4-triazolo[1,5-a] pyrimidin-5(1H) -one system are nearly coplanar. The crystal packing is mainly stabilized by weak intermolecular C-H···O hydrogen bond and π-π interactions.     

Interaction between the water soluble poly{1,4-phenylene-[9,9-bis(4-phenoxy butylsulfonate)]fluorene-2,7-diyl} copolymer and ionic surfactants followed by spectroscopic and conductivity measurements

The interaction has been studied in aqueous solutions between a negatively charged conjugated polyelectrolyte poly{1,4-phenylene-[9,9-bis(4-phenoxybutylsulfonate)]fluorene-2,7-diyl} copolymer (PBS-PFP) and several cationic tetraalkylammonium surfactants with different structures (alkyl chain length, counterion, or double alkyl chain), with tetramethylammonium cations and with the anionic surfactant sodium dodecyl sulfate (SDS) by electronic absorption and emission spectroscopy and by conductivity measurements. The results are compared with those previously obtained on the interaction of the same polymer with the nonionic surfactant C12E5. The nature of the electrostatic or hydrophobic polymer-surfactant interactions leads to very different behavior. The polymer induces the aggregation with the cationic surfactants at concentrations well below the critical micelle concentration, while this is inhibited with the anionic SDS, as demonstrated from conductivity measurements. The interaction with cationic surfactants only shows a small dependence on alkyl chain length or counterion and is suggested to be dominated by electrostatic interactions. In contrast to previous studies with the nonionic C12E5, both the cationic and the anionic surfactants quench the PBS-PFP emission intensity, leading also to a decrease in the polymer emission lifetime. However, the interaction with these cationic surfactants leads to the appearance of a new emission band (approximately 525 nm), which may be due to energy hopping to defect sites due to the increase of PBS-PFP interchain interaction favored by charge neutralization of the anionic polymer by cationic surfactant and by hydrophobic interactions involving the surfactant alkyl chains, since the same green band is not observed by adding either tetramethylammonium hydroxide or chloride. This effect suggests that the cationic surfactants are changing the nature of PBS-PFP aggregates. The nature of the polymer and surfactant interactions can, thus, be used to control the spectroscopic and conductivity properties of the polymer, which may have implications in its applications.     

[Ru(bpy)2(L-Trp)]ClO4-KCl水溶液体系的电致化学发光特性研究

合成了[Ru(bpy)2(L-Trp)]ClO4, 并对其电致化学发光特性进行研究。发现在KCl溶液中, 在三角波脉冲电压作用下, 该配合物在铂电极上有电致化学发光活性。其线性动力学响应范围为5.9×10^-^9～1.2×10^-^7mol . L^-^1。当信噪比为3时, 可检测浓度为5.9×10^-^9mol . L^-^1。浓度为5.9×10^-^8mol . L^-^1时, 10次测试的相对标准偏差为5.3%。根据电化学研究的结果, 提出了该配合物的电致化学发光反应机理。     

New synthesis of liquid polysulfide polymers in the presence of hydrazine. I. Synthesis of linear polysulfide polymers from 1,1′-[methylenebis (oxy)]-bis-[2-chloroethane] and sodium tetrasulfide

The results of our studies show that liquid linear polysulfide polymers of an average molecular weight 4260–1030 g mol⁻¹ can be obtained by the reaction of sodium tetrasulfide and 1,1′-[methylenebis(oxy)]-bis-[2-chloroethane] in the presence of 2.0–5.0 mol of hydrazine and at least 4.0 mol of sodium hydroxide/mol of hydrazine in a one-step procedure. The disulfide polymers in the form of sodium mercaptide are soluble in the supernatant liquid from which they are separated by acidification of the solution to a pH value of about 4. The average molecular weight and the content of sulfur in the obtained linear polymers were determined and their IR spectra were recorded. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1363–1367, 1997