Conductimetric investigations on salts in N,N-dimethylthioformamide at 25° C

Conductimetric measurements have been performed on solutions of the following salts in N,N-dimethylthioformamide (DMTF) at 25°C:- triisoamyl-n-butylammonium tetraphenylborate, triisoamyl-n-butylammonium iodide, triisoamyl-n-butylammonium perchlorate, tetra-n-butylammonium tetraphenylborate, tetra-n-butylammonium iodide, tetra-n-butylammonium perchlorate, bis(DMTF)copper(I)chloride, bis(DMTF)copper(I) bromide, bis(DMTF)copper(I) iodide, tetrakis(DMTF)copper(I) perchlorate, bis(DMTF)silver(I) chloride, bis(DMTF)silver(I) bromide and (DMTF)silver(I) iodide. The data have been analysed with the Pitts and the Fuoss—Justice conductivity equations and single ion conductivities have been calculated based on the assumption of equal limiting anion and cation conductivities for triisoamyl-n-butylammonium tetraphenylborate.     

表面改性对丁腈橡胶耐油及耐磨性能的影响

采用卤化(氟化、溴化、碘化)及混合氧化方法对丁腈橡胶表面进行化学改性,研究其对丁腈橡胶耐原油性能和摩擦磨损性能的影响,并借助SEM、摩擦磨损试验机等设备分析比较这几种方法的改性效果及其摩擦磨损机理。结果表明：氟化、溴化、碘化和混合氧化改性均能提高丁腈橡胶表面的拉伸强度、拉断伸长率、硬度等物理性能,其中氟化和混合氧化改性的效果尤其明显,碘化次之,溴化效果稍差;对丁腈橡胶表面进行卤化(氟化、溴化、碘化)改性并没有明显提高材料的耐油性能,而采用混合氧化方法改性的丁腈橡胶的耐油性能明显提高;改性后试样的耐磨性能均得到提高,其中混合氧化改性的效果最好,氟化次之,然后依次碘化、溴化。     

The use of N-bridgehead heterocyclic indolizinium ylide in the synthesis of aza-cyanine dyes

The reaction of 3-methyl-8-oxime-1-phenylpyrazolo [4,5-d]indolizinium (bezoindolizinium) ylide iodide with 2(4)-methyl substituted heterocyclic quaternary salts give 8[2(4)]-aza-monomethine cyanine dyes. Meanwhile, the reaction with carbonyl compounds followed by reaction with 2-methyl quinolinium methiodide salts afforded 5(2)-aza-trimethine cyanine dyes. On the other hand, the reaction of 5-formyl-2-methyl-4-phenylpyrazolo[4,5-d]indolizinium (benzoindolizinium) ylide iodide with hydroxylamine hydrochloride followed by reaction with N-methyl heterocyclic quaternary salts afforded the corresponding 5[4(1)]-aza-dimethine cyanine dyes. These new compounds are characterized with elemental analyses, visible absorption, IR, ¹³C NMR, ¹H NMR and mass spectroscopy. The correlations between the structure and spectral properties of these dyes have been studied.     

Thermodynamic and Surface Properties of Aqueous 1-Dodecyl-3-Methylimidazolium Chloride [C12mim][Cl] Solution in the Presence of a Series of Inorganic Salts

The micellization behavior of amphiphiles is a well-analyzed physicochemical phenomenon, which can be easily influenced by various parameters such as pressure, temperature, and the presence of different additives. Inorganic salts are able to affect the thermodynamic and surface properties of amphiphiles significantly. The effect of a series of salts as additives namely lithium chloride (LiCl), potassium chloride (KCl), sodium chloride (NaCl), sodium bromide (NaBr), and sodium iodide (NaI) on interfacial chemical characteristics of the surface-active ionic liquid (SAIL) 1-dodecyl-3-methylimidazolium chloride [C₁₂mim][Cl] in aqueous solution were examined through conductance, surface tension, fluorescence, ¹H NMR, and dynamic light scattering measurements. The interfacial and thermodynamic parameters of all investigated SAIL-salt systems were evaluated from surface tension and conductance measurements, respectively. A detailed analysis of the microenvironment of the micelles and the size of the micelles was done using ¹H NMR and dynamic light scattering measurements.     

Studies of tetra-(bipyridilium) salts as possible polyelectrochromic materials

A polybipyridilium species has been prepared with four diquaternised bipyridine moieties around a durene core; mixed halide (bromide with iodide or with chloride) as well as single-anion (chloride) salts were studied, and their electrochemistry investigated. Three reduction processes are inferred producing a pink (di-reduced) species, a purple (tetra-reduced) species and a beige-coloured fully-reduced product. Mixed anion effects, in conjunction with dimer association and comproportionation, led to more complicated anodic electrochemistry than when only chloride anions were involved.     

A new family of ionic liquids based on the 1-alkyl-2-methyl pyrrolinium cation

Five new salts based on 1-alkyl-2-methyl pyrrolinium ion are reported, two involving the iodide ion and three involving the bis(trifluoromethanesulfonyl) amide ion. The iodide salts have melting points around 100 °C, while the amide salts have melting points around room temperature. Two of the amide salts can be easily quenched into the glassy state and exhibit glass transition temperatures around −70 °C. The 2-methyl pyrrolinium cation bears structural similarities to the aromatic imidazolium cations on one hand and the cyclic ammonium cation family based on the pyrrolidinium cation on the other. The properties of the salts reported here are compared within these two related families of salts.     

Chemo-Enzymatic Synthesis and Antimicrobial Evaluation of Alkyloxy Propanol Amine-Based Cationic Ether Lipids

The present study involved the synthesis and antimicrobial evaluation of alkyloxy propanol amine-based cationic lipids N,N-dimethyl-1-octadecylamino-3-alkyloxy-2-propanol (series A, 7a–e) and N-methyl-N,N-di-(2-hydroxy-3-alkyloxy-2 propyl) octadecylamine (series B, 9a–e) and their acetylated derivatives (8a–e and 10a–e). A simple three-step chemo-enzymatic approach was employed for the synthesis of 7a–e and 9a–e in 71–80 and 67–88 % yields, respectively. The first step involved the synthesis of a series of glycidyl ethers from a series of alcohols (C₄, C₈, C₁₀, C₁₂, C₁₄) which were opened in the second step with octadecylamine to obtain 1-octadecylamino-3-alkyloxy-2 propanol (5a–e) and N,N-di-(2-hydroxy-3-alkyloxypropyl) octadecylamine (6a–e). In the third step, alkyloxy propanolamines (5a–e, 6a–e) were quaternized using methyl iodide to yield quaternized ammonium salts. The quaternized ammonium salts were enzymatically acetylated using Candida antarctica lipase-B based immobilized enzyme Novozym 435 to obtain their acetylated derivatives. The quaternized salts as well as their acetylated derivatives were evaluated for antibacterial and antifungal properties. The title compounds were found to possess moderate to good antibacterial activities against all the studied bacterial strains namely, Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Klebsiella aerogenes compared to streptomycin and cetyl trimethyl ammonium bromide (CTAB). The title compounds exhibited relatively good antifungal activities against Candida albicans and no significant activities against other fungal strains namely, Saccharomyces cerevisiae, Rhizopus oryzae and Aspergillus niger when compared to amphotericin B and CTAB.     

Organic halides as cationic initiators

The reaction of organohalides with silver hexafluorophosphate or silver perchlorate in THF to generate cationic initiators has been examined. Reactivities in the order fluoride < chloride < bromide < iodide and $\text{alkyl « allyl ≈ benzyl}$ were found. Selected halides were examined in more detail, and it was shown that under controlled conditions living poly THF could be obtained. This was difunctional if p-xylylene dibromide or 1,4-dibromobut-2-ene was used, or monofunctional with conventional monohalides. Molecular weight distributions of $\text{M}{}_{\mathrm{w}}\text{M}{}_{\mathrm{n}}\text{? 1.2}$ were obtained. Experiments demonstrated that allyl bromide and p-methylbenzyl bromide initiated THF polymerization entirely additively but, with isopropyl iodide at room temperature, up to 10% proton transfer occurred.     

Polymerization of methylmetacrylate in the presence of quaternary ammonium salts

Summary At 50°C, trioctyl methyl ammonium salts influence the rate of bulk polymerization of methylmetacrylate initiated by dibenzoyl peroxide. Acetate increases it, chloride, chlorate, and bromate increase it only on start, hydroxide, bromide, tetrachlorozincate, trifluoroacetate and trifluoromethanesulfonate decrease it, iodide and dichromate inhibit the polymerization, whereas fluoride, perchlorate, some (substituted) benzoates as well as sulfonates do not change the reaction rate. The influence on kinetic parameters of polymerization and the formation of intermediates and products suggest that the exchange of anions between the quaternary ammonium salt and dibenzoyl peroxide is the primary mechanism of action of these salts and other effects accompany it.     

Thermal and electrochemical properties of morpholinium salts with bromide anion

The present work is a study of the thermal properties and electrochemical stabilities of N-ethyl-N-methylmorpholinium bromide ([Mor_1,2][Br]), N-butyl-N-methylmorpholinium bromide ([Mor1_1,4][Br]), N-octyl-N-methylmorpholinium bromide ([Mor1_1,8][Br]), N-dodecyl-N-methylmorpholinium bromide ([Mor1_1,12][Br]), and N,N-dihydroxyethylmorpholinium bromide ([DHEMor][Br]). The melting points, decomposition temperatures, and electrochemical stabilities of the salts were measured by DSC (differential scanning calorimetry), TGA (thermogravimetric analysis), and CV (cyclic voltammogram), respectively. All salts were decomposed below approximately 230.00 °C and their melting points were above 100.00 °C except [DHEMor][Br], which melted at 75.17 °C. [DHEMor][Br] appeared to possess the most wide liquid-phase range between melting point and decomposition temperature. The electrochemical windows of salts ranged from 3.3 V for [Mor_1,8][Br] to 3.6 V for [Mor_1,4][Br] and thus did not show any noticeable variation with cations used for salt synthesis.     

Micellization Studies of Dicationic Gemini Surfactants (m-2-m Type) in the Presence of Various Counter- and Co-Ions

Salts have the ability to influence the water activity and self-association of ionic micelles. In the present case, gemini surfactants; ethanediyl-α,ω-bis(dimethyl alkyl ammonium bromide) (referred to as m-2-m, m = 10, 12, 14) are synthesized and their micellization study in aqueous medium in presence of monovalent inorganic (NaBr, NaNO₃, NaCl, KCl, LiCl) and organic salts (NaTos, NaBenz, NaSal) at 303 K is systematically investigated by conductometric and tensiometric methods. All the salts have the tendency to lower the critical micelle concentration of the surfactants. The effect of inorganic salts on the micellization properties has been found to obey the Hofmeister series. Organic salts reduce the CMC more effectively as compared to inorganic salts. The theoretical models of Rubingh and Rosen have been used to compare the results and obtain the interaction parameters, minimum area per molecule, surface excess, mixed micelle composition, activity coefficients and free energies of micellization/adsorption.     

Synthesis of novel fluorescent styryl dyes based on the imidazo[1,2-a]pyridinium chromophore and their spectral-fluorescent properties in the presence of nucleic acids and proteins

The imidazo[1,2-a]pyridinium heterocyclic system was used to prepare styryl dyes. Improved synthetic methods were proposed for the parent imidazo[1,2-a]pyridines and their corresponding quaternary salts. The standard method for preparing styrylcyanines was modified for the synthesis of the target imidazo[1,2-a]pyridinium dyes. Spectral-luminescent properties of the obtained dyes in free state and in the presence of nucleic acids, BSA, and BSA/detergent system were studied. 7-[2-(4-Dihexylaminophenyl)-1-ethenyl]-2-(2,4-dimethoxyphenyl)-1-ethylimidazo[1,2-a]pyridin-1-ium iodide (SIP-8) containing C₆ aliphatic tails and 2,4-methoxy substituents in the 2-phenyl ring exhibited specificity to BSA.     

Influence of anions on the corrosion of high speed steel

Corrosion potential measurements, voltammetric techniques and electrochemical impedance have been used to evaluate the corrosion resistance of M2 high speed steel in aqueous solutions containing chloride, bromide, iodide, nitrate, sulfate and perchlorate salts of sodium and potassium of varying concentration. The influence of changing the cation was found to be small and an order of anion aggressivity was established as: sulfate>chloride>bromide>perchlorate>iodide>nitrate. The data obtained are important for the diagnosis, prediction and analysis of corrosion processes due to the breakdown of sputtered coatings on M2 steel in diverse environments.     

Electrolyte—solvent interaction in the dipolar aprotic solvent dimethyl sulphoxide at 25°C

Conductance measurements are reported for s-alkylisothiouronium bromide, iodide and picrate salts in the dipolar aprotic solvent DMSO at 25°C. The data were analysed by Fuoss's equation (1975–1980) for 1:1 electrolytes, from which the values of Λ₀, the Gurney's cosphere diameter R and K_A are obtained. The results are discussed in the light of the recorded values of the constants K_R and K_S and the free energy term G_s.     

季铵卤化银的制备及其热分解特性(英文)

季铵盐如十六烷基三甲綦经铵(CTAB)或十六烷基碘化铵(CTAI)与硝酸银反应得到新的沉淀物A,B,C和D。测试沉淀物的元素组成以及XRD,TG-DTA和IR,表明沉淀物是不于卤化银的新的化合物,暂时叫做季铵卤化银如十六烷基三甲基溴化银铵或十六烷基三甲基碘化银铵。分子式是A:C19H42NAg2Br3;B:C19H42NAgBr3;C:C19H42NAg2I3;和D:C19H42NAgI2;.我们季铵卤化银是季铵阳离子部分取代卤化银分子中的银离子的结果。     

国际影像公司中国专利申请分析报告(一)

21世纪是影像业快速向数字化、网络化发展的时代。传统影像材料公司、影像器材生产商和IT企业纷纷汇集于这一极具发展前景的产业,竞争日益激烈,其中面对中国市场,各大公司都寄予厚望。对国际大公司申请的中国专利情况进行跟踪分析,有助于我们及时掌握国内技术和市场的发展动向,开阔思路,激发创新灵感。本次分析报告针对惠普、佳能、富士、柯达、精工爱普生、柯尼卡美能达、爱克发和三菱制纸八家公司,统计了公开日从2001年至2005年6月的近9000件中国专利。报告主要分为3个部分:(1)通过对比各公司在全球、本国和中国的专利数据,从侧面了解各公司的经济实力、技术创新能力、对外发展战略、对中国市场的定位以及对中国市场创新性技术投入的策略;(2)对各公司的专利数据按照所属技术领域进行归纳和分析,详细分析各公司近年来中国专利技术的全貌、重点技术领域、最新发展动向以及采取的专利策略;(3)对各公司中国专利涉及的主要技术领域作简要的横向对比,由此从产业全景角度,发现重点领域,挖掘空白领域,并提出有关未来技术发展和专利工作的一些建议。     

Polyphenylglyoxamide-Based Amphiphilic Small Molecular Peptidomimetics as Antibacterial Agents with Anti-Biofilm Activity

The rapid emergence of drug-resistant bacteria is a major global health concern. Antimicrobial peptides (AMPs) and peptidomimetics have arisen as a new class of antibacterial agents in recent years in an attempt to overcome antibiotic resistance. A library of phenylglyoxamide-based small molecular peptidomimetics was synthesised by incorporating an N-alkylsulfonyl hydrophobic group with varying alkyl chain lengths and a hydrophilic cationic group into a glyoxamide core appended to phenyl ring systems. The quaternary ammonium iodide salts 16d and 17c showed excellent minimum inhibitory concentration (MIC) of 4 and 8 μM (2.9 and 5.6 μg/mL) against Staphylococcus aureus, respectively, while the guanidinium hydrochloride salt 34a showed an MIC of 16 μM (8.5 μg/mL) against Escherichia coli. Additionally, the quaternary ammonium iodide salt 17c inhibited 70% S. aureus biofilm formation at 16 μM. It also disrupted 44% of pre-established S. aureus biofilms at 32 μM and 28% of pre-established E. coli biofilms 64 μM, respectively. A cytoplasmic membrane permeability study indicated that the synthesised peptidomimetics acted via disruption and depolarisation of membranes. Moreover, the quaternary ammonium iodide salts 16d and 17c were non-toxic against human cells at their therapeutic dosages against S. aureus.     

An Eco-Friendly Ultrasound-Assisted Synthesis of Novel Fluorinated Pyridinium Salts-Based Hydrazones and Antimicrobial and Antitumor Screening

The present work reports an efficient synthesis of fluorinated pyridinium salts-based hydrazones under both conventional and eco-friendly ultrasound procedures. The synthetic approach first involves the preparation of halogenated pyridinium salts through the condensation of isonicotinic acid hydrazide (1) with p-fluorobenzaldehyde (2) followed by the nucleophilic alkylation of the resulting N-(4-fluorobenzylidene)isonicotinohydrazide (3) with a different alkyl iodide. The iodide counteranion of 5–10 was subjected to an anion exchange metathesis reaction in the presence of an excess of the appropriate metal salts to afford a new series of fluorinated pyridinium salts tethering a hydrazone linkage 11–40. Ultrasound irradiation led to higher yields in considerably less time than the conventional methods. The newly synthesized ILs were well-characterized with FT-IR, ¹H NMR, ¹³C NMR, ¹¹B, ¹⁹F, ³¹P and mass spectral analyses. The ILs were also screened for their antimicrobial and antitumor activities. Within the series, the salts tethering fluorinated counter anions 11–13, 21–23, 31–33 and 36–38 were found to be more potent against all bacterial and fungal strains at MIC 4–8 µg/mL. The in vitro antiproliferative activity was also investigated against four tumor cell lines (human ductal breast epithelial tumor T47D, human breast adenocarcinoma MCF-7, human epithelial carcinoma HeLa and human epithelial colorectal adenocarcinoma Caco-2) using the MTT assay, which revealed that promising antitumor activity was exhibited by compounds 5, 12 and 14.     

O-alkylation of disodium salt of diethyl 3,4-dihydroxythiophene-2,5-dicarboxylate with 1,2-dichloroethane catalyzed by ionic type phase transfer catalyst and potassium iodide

Diethyl 3,4-ethylenedioxythiophene-2,5-dicarboxylate was efficiently synthesized via the O-alkylation of disodium salt of diethyl 3,4-dihydroxythiophene-2,5-dicarboxylate with 1,2-dichloroethane over ionic type phase transfer catalysts, such as tetrabutyl ammonium bromide and benzyltriethyl ammonium chloride. The ionic type phase transfer catalysts showed higher catalytic activities than the nonionic type phase transfer catalysts, such as triethylamine, pyridine, 18-crown-6, and polyethylene glycol 400/600, in the O-alkylation reaction. The conversion of the disodium salt of more than 97% and the selectivity of diethyl 3,4-ethylenedioxythiophene-2,5-dicarboxylate of more than 98% were achieved when the O-alkylation reaction was synergistically catalyzed by tetrabutyl ammonium bromide and potassium iodide.     

Dicationic bis-imidazolium molten salts for efficient dye sensitized solar cells: Synthesis and photovoltaic properties

New dicationic bis-imidazolium salts based ionic liquids were synthesized to develop new electrolytes to improve photovoltaic properties of dye sensitized solar cells. Various properties of electrolytes such as viscosities, ion diffusion coefficients, charge transfer resistances and photovoltaic properties were studied. Electrochemical impedance spectroscopy has been performed to investigate diffusion coefficients and charge transfer resistances. Influence of polarity and chain length on the photovoltaic performance, was investigated. A DSSC employing the K34 (butyl-1,4-bis(3-methyl imidazolium iodide) gives an open-circuit voltage of 0.64 V, a short-circuit current of 17.11 mA/cm² and conversion efficiency of 5.60% under light intensity of 100 mW/cm² while the DSSC based on 1-butyl-3-methyl imidazolium iodide which is a reference ionic liquid exhibited 5.64% efficiency due to the lowest viscosity, highest diffusion coefficient.