POLYMER—SUPPORTED SINGLE AND MIXED AMMONIUM AND PHOSPHONIUM SALTS AS CATALYSTS FOR PHASE—TRANSFER REACTIONS

In this study was to investigate,by phase-transfer catalysis,the activity of single and mixed ammonium and phosphonium salts grafted on a “gel-type“ stryene-7% divinylbenzene copolymer in the oxidation of benzyl alcohol with hydrogen peroxide.A wide variety of catalysts with different quaternary groups and different quaternary chain length substitutents were examined.The activity of single“onium“salts increases as a consequence of the association of ammonium and phosphonium salts grafted onn the same polymeric support.The activity of polymer-supported ammonium and phosphonium salts increases with the number of carbon atoms contained in the alkyl radicals of the -onium and of the functionalization degree with phosphonium groups.     

POLYMER-SUPPORTED SINGLE AND MIXED AMMONIUM AND PHOSPHONIUM SALTS AS CATALYSTS FOR PHASE-TRANSFER REACTIONS

1. INTRODUCTION A variety of organic reactions have recently been reported to be catalysed by quaternary ammonium and phosphonium salts [1~4]. In same time, the attachment of phase-transfer catalysts to insoluble polymer supports greatly simplified their use in organic reactions [5~7]. The aim of this study was to investigate the effects of single and mixed ammonium and phosphonium salts, grafted on a 揼el-type?styrene-7% divinylbenzene copolymer, upon the phase-transfer catalytic process…     

Modified gelatin with quaternary ammonium salts containing epoxide groups

An EPDDMAC-GE polymer （hydrophilic molecule） has been synthesized based on epoxypropyl dodecyl dimethyl ammonium chloride （EPDDMAC） and gelatin. A DEEPSAC-GE polymer （hydrophobic molecule） has been synthesized based on diethyl-2,3-epoxypropyl-[3-methyldimethoxyl] silpropyl ammonium chloride （DEEPSAC） and gelatin. Compared with initial gelatin, the gelatin modified with quaternary ammonium salts containing epoxide groups exhibits stronger antibacterial activity.     

Synthesis and Antimicrobial Properties of the Novel Fluorinated Bis-ammonium Salts with Two Primary Amine Groups

In order to resolve the increasing resistance phenomena of the Gram-negative bacteria against single chain quaternary ammonium salts （QAS）, lysine with a pedant fluorinated bis-ammonium salts was synthesized and its antimicrobial properties were evaluated in this work. The novel fluorinated bis-ammonium salts shows similar activity with conventional single chain quaternary ammonium salts against Gram-positive bacteria but stronger activity against Gram-negative bacteria and yeast compared with the single chained counterpart.     

Synthesis and Antimicrobial Properties of the Novel Fluonnated Bis-ammonium Salts with Two Primary Amine Groups

In order to resolve the increasing resistance phenomena of the Gram-negative bacteria against single chain quaternary ammonium salts (QAS), lysine with a pedant fluorinated bis-ammonium salts was synthesized and its antimicrobial properties were evaluated in this work. The novel fluorinated bis-ammonium salts shows similar activity with conventional single chain quaternary ammonium salts against Gram-positive bacteria but stronger activity against Gram-negative bacteria and yeast compared with the single chained counterpart.     

Study on the synthesis and antimicrobial activity of novel cationic porphyrins

A novel series of quaternary ammonium cationic derivatives based on tetrapyridyl-porphyrin was synthesized.All the compounds were evaluated for their in vitro antibacterial activities against S.aureus,E.coli and P.aeruginosa,and antifungal activities against C.albicans,where microorganisms were exposed and unexposed to the irradiation.The results revealed that some of these compounds,especially,3a and 4a displayed satisfactory antibacterial activity against Gram-positive bacteria S.aureus and moderate an...     

STUDIES ON RESPONSE CHARACTERISTICS OF DRUG ION-SELECTIVE ELECTRODES (Ⅱ)——SULPHA-DRUG SENSITIVE ELECTRODES USING QUATERNARY PHOSPHONIUM AND ARSONIUM COMPOUNDS

Ion-pair complexes of sulphonamide derivatives with quaternary phosphonium and quaternary arsonium have been synthesized and their electrode performances studied. It has been found that the electrode functions depend mainly on the site cation rather than on the anionic species and deteriorate in the order of cetyhrioctylammonium>cetyltriphenylphosphonium> cetyhriphenylarsonium. The electrode selectivity for different sulpha-drugs decreases in the order of sulphathiazole>sulphamethoxazole>sulphadimethoxine, sulphadoxine>sulphacetamide>sulphadiazine>sulphanilamide. Selectivity coefficients depend not only on the molecular connectivity index χ, but also on the electronic charge at the ionizing amide nitrogen atom σ and pK, according to the following formula: logK_(ij)=aχ+bσ—CpK_a—d. The quaternary phosphonium type electrodes have been suggested for use in the potentiometric determinations of sulpha-drugs.     

Synthesis and Antibacterial Activity of New Cephalosporin Compounds

The fourth generation cephalosporin cefepime I exhibited potent antibacterial activity with board antibacterial spectrum1,2.Based on the structure of cefepime,we synthesized its analogs Ia having fluoro atom at the aminothiazolyl oxime moiety at the7-position of the cephem nucleus,and Ib possessing1-(2-fluoroethyl)pyrrolidium methyl group at the3-position.It was reported that cephalosporin derivatives with a quaternary ammonium moiety at the3-position of the cephem nucleus,showed enhanced ant…     

SYNTHESIS AND CATALYSTIC BEHAVIOR OF A HEW PHASE-TRANSFER CATALYST SUPPORTEI) OB SILICA GEL

A new catalyst with quaternary ammonium cation activated polyether chains immobilized on silica gel was applied to promote the reations of KI with n-C_4H_9-Br and KSCH with n-C_4H_9Br. The new catalyst showed much significant activity over other PEG functionalized silica gel.     

PREPARATION AND PHOTOSENSITIVITY OF WATER SOLUBLE PHENOLIC RESINS CONTAINING ACRYLOYL AND QUATERNARY AMMONIUM CHLORIDE GROUPS

New water soluble and photocrosslinkable prepolymers colltaining acrylate and quaternary ammonium salt groupswere synthesized from epoxy phenolic resin via ring-opening reaction with acrylic acid and with aqueous solution oftriethylamine hydrochloride successively. The second reaction needs no phase transfer catalyst to accelerate, since theproduct formed can act as a phase transfer catalyst. The prepolymer obtained contains both photocrosslinkable acrylategroups and hydrophilic quaternary ammonium salt groups. Optimum conditions for these reactions were studied. Thephotosensitivity of the prepolymer was also investigated. The effects of different photoinitiators, different crosslinkablediluent monomers and amine accelerator on the photosensitivity of the prepolymer were compared. The photoinitiator ofhydrogen abstraction type is still effective without using amine or alcohol as accelerator, because the prepolymer containsα H beside the OH groups formed in the ring-opening reactions     

Studies on Solid-Liquid Phase Transfer Equilibrium of Onium Salts(Ⅱ)

The present paper contains the effects of the ammonium ion, counter ion, solvent and anion being transferred on the solid-liquid phase transfer equilibrium constant of quaternary ammonium salts. The most striking difference between solid-liquid and liquid-liquid phase transfer equilibriums is that the length of alkyl chain shows a large effect on the latter but little on the former This means that the chain length affects only the hydrophobicity, rather than the lipophilicity.Keywords Quaternary ammonium salt, Phase transfer catalysis, Equilibrium constant, Hydrophobicity, Lipophilicity     

Synthesis and Spectroscopic Characterisation of 2,3‐Epoxy/ 3‐Chloro‐2‐hydroxy Propyl Derivatives of Quaternary Ammonium Salts:Useful Cationic Fixing Agents

Eight mono-reactive and four bis-reactive 2,3-epoxy/3-chloro-2-hydroxy propyl derivatives of quaternary ammonium salts have been synthesised by reacting epichlorohydrin with suitable tertiary amines and diamines. Mono-reactive derivatives also contain cyano and carboxylic groups in addition to 2,3-epoxy/3-chloro-2-hydroxy propyl groups. The structures of these quaternary ammonium salts have been characterised using IR and ¹H NMR spectroscopic techniques. These quaternary ammonium chlorides have been applied to the cotton fabrics as pretreatments and aftertreatments and promising results have been obtained.     

Characterization and phase transition study for vesicles of fluorocarbon amphiphiles with 1,3-disubstituted glycerol structure

This paper presents the preparations and characterization of vesicles of four new fluoro-carbon amphiphiles with 1,3-disubstituted glycerol structure in common and different headgroups(OH, 1; CO_2H, 2; quaternary ammonium salt, 3; and pyridinium salt, 4). These vesicles havehigher transition temperature due to the stronger hydrophobic interaction between fluorocarbonchains. Addition of fluorocarbon additives with carboxylic acid or quaternary ammonium salt headgroup respectively shows different influences on phase behavior of vesicles of 2. These results arediscussed based on the interaction within headgroup, hydrophobicity and specific mutahydrophobicinteraction between fluoro- and hydrocarbon chains.     

ε-Poly(L-lysine)-based Hydrogels with Fast-acting and Prolonged Antibacterial Activities

Bacterial infections and the associated morbidity and mortality due to bacterial pathogens in wounds and medical implants have been increasing as most of current coatings cannot fulfill all the requirements including excellent intrinsically antibacterial activity,low cytotoxicity, and favorable physical properties. Herein, we present a kind of antibacterial hydrogel based on ε-poly(L-lysine)(EPL)grafted carboxymethyl chitosan(CMC-g-EPL) as the inherently antibacterial matrix and the surplus EPL as highly efficient antimicrobial agent. Such hydrogels possess tunable swelling abilities with water absorption percentages of 800%–2000% and modulus varying from10 kPa to 100 kPa, and exhibit two-stage excellent antibacterial behavior. First, the free EPL can be released from the hydrogel network for quick and highly efficient bacteria killing with 99.99% of efficacy; second, the grafted EPL endows hydrogel matrix with prolonged intrinsically antibacterial activity, especially when most of free EPL is released from the hydrogel. Overall, we provide a new insight for preparing highly effective antibacterial hydrogels.     

Facile Fabrication of Hyperbranched Polyacetal Quaternary Ammonium with pH-Responsive Curcumin Release for Synergistic Antibacterial Activity

In the current global crisis of antibiotic resistance, persuit of an effective multi-pathway collaborative approach to enhance antibacterial activity is urgently needed. Here, a kind of hyperbranched polyacetal quaternary ammonium(Hyper-ace-QA) with efficiently antibacterial function were synthesized by a succession of efficient click strategies. The high molecular weights can be obtained just after UV irradiation for 3 h, and the grafting ratio can be easily adjusted through controlling solvent...     

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.     

SYNTHESES AND ANTIMICROBIAL ACTIVITY OF NOVEL POLYURETHANE IONOMERS

This study is concerned with the removal of Staph aureus from water by polyurethaneionomers. All the samples are quaternary ammonium salts which possess a positive chargeon the surface. The ratio of the soft segment to diisocyanate and chain extender is 1:2:1and the ionization degree is 100%. The ionomers strongly capture microbial cells on theirsurfaces in a living state and the hydrophilicity of polymer matrix used in the studyenhanced the affinity of the polymer for bacterial cells. The adhesion of the microorganismto polymer was due mainly to electrostatic interaction between them. The calculation ofthe viable cell count showed that D value for Staph.aureus is not proportional to the nitro-gen concentration. The microorganism capture ability of pyridinium-containing polymer isgreater than that of piperazine based samples.     

STUDIES ON THE ACTIVITY COEFFICIENTS OF NONELECTROLYTES IN AQUEOUS SALT SOLUTIONS——Ⅱ. THE EFFECTS OF SALTS OF FATTY ACIDS AND QUATERNARY AMMONIUM SALTS ON THE SOLUBILITIES OF NAPHTHALENE IN WATER

On the assumption that the salt effect (salting-out or salting-in) representsthe balance of the electrostatic effect between the ion and the water dipole andthe dispersion effect between ion and nonelectrolyte molecule, the solubilitiesof n-valeric acid in five cobaltammimes were studied and reported in article Ⅰof this series. In the present investigation the activity coefficients of naph-thalene in two series of salts are determined spectrophotometrically. The firstseries consists of seven sodium salts of fatty acids (sodium formate to sodiumn-heptylate), differing from one another only by the number of CH_2 groups inthe anions. The second series consists of ammonium bromide and three tetra-     

Synthesis of novel quaternary ammonium surfactants containing adamantane

A series of novel quaternary ammonium surfactants containing adamantane were designed and synthesized from 1-adamantanecarboxylic acid.The structures of target surfactants were confirmed by]H NMR,elements analysis and FTIR.Surface properties of these surfactants were investigated.Due to the lipophilicity of adamantane,the critical micelle concentration（CMC） and C₂₀ values of the synthesized quaternary ammonium surfactants are lower than that of conventional quaternary ammonium surfactants.     

STUDIES ON RESPONSE CHARACTERISTICS OF DRUG ISE''''S (Ⅲ)——ERYTHROMYCIN ELECTRODES AND THEIR SELECTIVITY TOWARD QUATERNARY AMMONIUMS

Erythromycin sensitive electrodes have been proposed. Their selectivity toward quaternary ammoniums is described in terms of induction effect and steric hindrance effect: logKil=a_1I-a_2Z/R+a_0, where I is induction effect index, a_1,a_2 and a_0 are coefficients which depend on the electro-active material. A general formula has been suggested to relate the electrode selectivity to the carbon atom number (n) of the alkyl of the quaternary ammonium; logK_(ij)=A/2.7~R-B/(0.80+1.26n)+C, where A, B and C are coefficients which depend on the electro-actlve material, logK_(ij) tends to a limited value C when n increases.