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A straightforward photo-annealing approach was developed for building functional polymer layers on paper. Conducting polyaniline with the ability for photothermal conversion can be readily annealed by near-infrared light. The annealed polymers become both insulating and hydrophobic. Selective photo-annealing produces a functional layer with patterned conductive arrays. This material exhibits real-time response to ammonium gas. Complete photo-annealing preserves the porous structure but changes the wettability of the polyaniline-nanofiber film. [ABSTRACT FROM AUTHOR]

A response to the comment by Gernot Frenking, outlining common ground, as well as differences, with regard to a recent paper on charge-shift bonding in quaternary ammonium cations. [ABSTRACT FROM AUTHOR]

There is an urgent need to develop green catalytic transesterification technology to reduce liquid waste and instrument corrosion. Ionic liquids with controlled activity, easy recovery, and corrosion resistance have great potential as catalysts for transesterification reactions. In this paper, a series of ionic liquids were prepared using imidazole and ammonium compounds as cations, and sulphuric acid, p‐toluenesulfonate, and bistrifluoromethanesulfonate anions as anions. In comparison, the ionic liquid made from imidazole with H2SO4 (IMIHS) was found to be the best catalyst for the esterification reaction with high speed, high activity, low corrosion, and high stability, and its catalytic performance was superior to that of sulphuric acid. The optimum reaction conditions were as follows: the molar ratio of ethanol to acetic acid was 1:1, the catalyst amount was 5 wt.%, the reaction temperature was 80°C, and the reaction time was 120 min. The maximum yield of ethyl acetate was 66.2% under the optimum reaction conditions. The catalytic activity was not declined obviously by reusing six times. The activation energy of the reaction is 48.748 kJ/mol. [ABSTRACT FROM AUTHOR]

In this paper, we present the synthesis of new selenoloquinoxaline derivatives starting from 2‐chloroquinoxaline‐3‐carbonitrile 1. The compound 1 was subjected to a reaction with selenium metal in the presence of NaBH4 as a reducing agent in ethanol, under a nitrogen atmosphere. This reaction resulted in the formation of the sodium salt of 3‐cyanoquinoxaline‐2‐selenolate, which was subsequently reacted with α‐halogenated carbonyl compounds in situ. This reaction produced a series of newly synthesized 3‐aminoselenolo[2,3‐b]quinoxaline‐2‐substituents. Ethyl 3‐aminoselenolo[2,3‐b]quinoxaline‐2‐carboxylate 3a was hydrolyzed by sodium hydroxide to give the corresponding sodium salt 9. This salt was then refluxed with acetic anhydride to produce oxazinone compound 10. The reaction of compound 10 with ammonium acetate afforded pyrimidoselenolo[2,3‐b]quinoxaline derivative 11. Compound 11 was then chlorinated using phosphorous oxychloride to give the corresponding chlorocompound. [ABSTRACT FROM AUTHOR]

The paper by Gershoni-Poranne and Chen (R. Gershoni-Poranne, P. Chen, Chem. Eur. J. 2017, 23, 4659) gives an incorrect definition of covalent bonding. Furthermore, the assignment of so-called charge shift bonds in ammonium compounds has no physical foundation and is conceptually redundant. [ABSTRACT FROM AUTHOR]

This paper describes a new analytical method, using a combination of ammonium pyrrolidine dithiocarbamate/methyl isobutyl ketone (APDC-MIBK) microextraction and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), for the determination of the concentrations of Cd and Pb in aqueous samples. Only 200 μL of organic solvent was used throughout the entire analysis process, with enhancement factors as high as 25. Recoveries from replicate analyses of natural water [NIST 1640(a)] containing mean concentrations of 3.1 μg Cd L−1 and 9.3 μg Pb L−1 were 95 ± 3 and 104 ± 4%, respectively. The corresponding detection limits were 0.6 μg L −1 for Cd and 0.9 μg L −1 for Pb. The main advantage of this approach is its simplicity in terms of sample preparation, as demonstrated by quantifying the levels of Cd and Pd in real samples, including tap water, groundwater, and seawater, using a standard addition method. [ABSTRACT FROM AUTHOR]

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This paper reports works conducted on intumescent stereocomplexed polylactide synthesized for the first time by reactive extrusion. This reactive extrusion process is an innovative, efficient and ecofriendly way to product polylactides. This stereocomplexed polylactide results from the two-step polymerization of L-lactide and D-lactide to yield poly-L,D-lactide multiblocks. Our reactive extrusion process permits to make polylactide matrix able to form stereocomplex crystallinity and to incorporate flame-retardant additives during synthesis at the same time. This material can be molded keeping its stereocomplex crystallinity. The flame retardants which are a combination of ammonium polyphosphate, melamine and organoclay provide an intumescent behavior upon heating to the stereocomplex, and the flame-retarded material exhibits very low flammability (peak of heat release rate is decreased by 83% and total heat released is decreased by 95% during cone calorimetry experiment). Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The Indian Environmental Protection Act (EPA) came into force in 1986 after Bhopal Gas Tragedy. It stipulates that no person or industry or processor shall discharge or emit environmental pollutants in excess of prescribed standards. Dihydroxyl ammonium 5,5′-bistetrazole-1,1′-diolate, abbreviated as TKX-50, was synthesized in this laboratory. During synthesis of TKX-50 a large volume of effluent was generated, which was acidic and hazardous in nature and therefore can damage the environment if discharged without proper treatment. Literature survey reveals that TKX-50 effluent analysis and its treatment have not been reported so far. In order to meet EPA norms and protect the environment TKX effluent samples of different steps of synthesis were collected and analyzed for environmental parameters such as pH, chemical oxygen demand (COD), bio-chemical oxygen demand (BOD), total dissolved solids (TDS) and bioassay test (toxicity to zebra fish survival) followed by the treatment of composite effluent. This paper presents analysis results of TKX-50 effluent samples before and after treatment. The results of finally treated TKX-50 effluent indicate that the same can be safely discharged on land for irrigation without adverse effect on environment. This study may be suitable for environmentalists and community of high energy materials. [ABSTRACT FROM AUTHOR]

The paper concerns factors which affect the binding and plaque-inhibiting effect of chlorhexidine-digluconate (CM) in the human oral cavity. About one-third of the administered dose was retained after mouth rinses (0.05-0.40% w/v) and after toothbrushing with a CH gel (1% w/w) measured by [14C]-chlorhexidine. The following CH concentration in saliva showed an almost logarithmic fall during the first 4-8 h, followed by a more steady low concentration, with CH still present after 24 h. The amount retained after mouth rinses increased almost linearly with the increase in the concentration. Time studies showed that about 55% of the amount retained after 60 sec was retained after the first 15 sec. Lowering the pH of the rinsing solution reduced the retention, and increase in ionic strength of after-rinses increased the release of CH. Calcium in a 250 mM concentration significantly reduced the retention and increased the release when present in after-rinses. The detergent sodium dodecyl (lauryl) sulphate greatly reduced both the retention and the plaque-inhibiting effect. Comparative studies between CH and quaternary ammonium compounds showed that 60-65% of the quaternaries was retained, compared to 32% of CH. When used four times daily, the plaque-inhibiting effect of the quaternaries approached that of CH. Their concentration in saliva fell more rapidly than that of CH. [ABSTRACT FROM AUTHOR]

In paper [5] a simplified model for the hydrophobic binding sites of trypsin was proposed, showing where 1-amino-n-alkanes and α,ω-diamino-n-alkanes are bound while they competitively inhibit the catalyzed hydrolysis of a substrate ester. In the model, the enzyme bas two hydrophobic binding sites separated by an aqueous region which presumably contains the catalytic important residues. The first site binds up to 4 methylene groups of the aliphatic side chain adjacent to the ω-amino group: additional—CH2 groups in t, he chain extend into the aqueous region. If the chain is larger than 7 carbon atoms, the additional methylene or methyl groups are bound to the second hydrophobic site. This site is found to bind less strongly than the first site. This paper presents a thermodynamic investigation of the binding properties of trypsin in the formation of complexes with cationic esters and amids which bear an ammonium group on either the end of the acid side chain or the end of the alcohol or amine component. Free energy and in addition enthalpy and entropy of binding were measured as a function of the length of the inhibitor molecule and as a function of the position of the ester or amide carbonyl group. It was found that thc stability of a complex increases linearly with length of the molecule, and that the magnitude of increase depends on the position of the carbonyl group. Amides always exhibit a smaller increase than esters. Inhibitors with the ammonium group on the alcohol component, were bound with about, the same stability than the corresponding ω-aminoacidesters. The results are consistent, with the model. Positioning of the carbonyl group within the first or second binding site reduces stability due to restricted interaction of the hydrophobic residues on enzyme and inhibitor. Only when the carbonyl group falls into the aqueous region, the free energy for an inhibitor containing the ester group is similar to that for a 1-amino-n-alkane with identical chain length. Enthalpy and entropy as functions of the position of the carbonyl group show minima for the position within the aqueous region. This observation is correlated with the jump of enthalpy and entropy of complex formation of trypsin in the series of 1-amino-n-alkanes reported earlier. It is shown that the magnitude of free energy of complex formation with specific substrates is well estimated on basis of the model. As a consequence, the alternative binding of either the 2-N-acyl group or the alcohol or amine component, to the second hydrophobic site may imply a mode of less productive binding. It is emphasized that unproductive binding should be reflected in the Michaelis Menten constants for substrate amides whereas thc Michaelis Menten constant, for a substrate ester is normally not perturbed. [ABSTRACT FROM AUTHOR]

A novel and efficient approach to sulfonamides has been developed. Using TBHP as the oxidant and NH4I (20 mol%) as the catalyst, arylsulfonyl hydrazides reacted with amines to provide sulfonamides in moderate to good yields. Possible reaction pathway for the formation of the products was also discussed in this paper. [ABSTRACT FROM AUTHOR]

In this paper, β-cyclodextrin (CD) was used as effective 'green' carbon source to replace pentaerythritol (PER) in an intumescent flame retardant (IFR). The combination of CD with traditional acid resource ammonium polyphosphate (APP) and/or blowing agent melamine (MA) at different weight ratios exhibited outstanding char-forming ability. It was demonstrated that strong interactions occurred in APP-CD and MA-CD systems through thermogravimetric analysis (TGA). Mechanisms of esterification between APP and CD or dehydration between MA and CD were discussed. The APP/MA/CD complexes showed doubled char residue of those calculated based on three single components in nitrogen atmosphere. For instance, the char residue of CD-APP (at the weight ratio of 1:1) complex was 38 wt% at 700°C, while the calculated char formation was only 19 wt% in N [ABSTRACT FROM AUTHOR]

In this paper, a software sensor based on a fuzzy neural network (FNN) approach was proposed for the real-time estimation of nutrient concentrations and overcoming the problem of delayed measure- ments. To improve the FNN performance, fuzzy subtractive clustering was used to identify the model's architecture and optimize the fuzzy rule; meanwhile, a split network structure, applied separately for anaerobic and aerobic conditions, was used with dynamic modeling methods, such as an auto-regressive model with exogenous inputs. The proposed methodology was applied to a bench-scale anoxic/oxic process for biological nitrogen removal. It was possible to partially overcome the extrapolation problem of FNNs with the aid of multi-way principal component analysis, because it has the ability to detect abnormal situations, which could generate extrapolation. Real-time estimation of chemical oxygen demand, nitrate, and ammonium concentrations based on the model was successfully carried out with the simple online information of the anoxic/oxic system. Water Environ. Res., 81, 654 (2009). [ABSTRACT FROM AUTHOR]

Thiolase was purified 600–700 fold from a crude extract of pig heart by use of differential adsorption on Al(OH)3 gel, ammonium sulfate fractionation and ion exchange chromatography on DEAE­Sephadex and phosphorylated cellulose. The enzyme preparation is homogenous by the following criteria: sedimentation analysis and electrophoresis on polyacrylamide gel and on cellulose acetate membranes. The isoelectric poit of the protein was found to be approximately pH 7.2–7.3. The enzyme crystallized from ammonium sulfate solutions as thin plates of irregular shape. Crystalline thiolase stored for 18 months at –10° did not show any loss of activity. The thiolytic activity and the acyl transferase activity of the enzyme could be demonstrated separately. The thiolytic activity was demontrated by the specific incorporation of 14C from [1 ­14C]­acetyl­CoA into the carboxyl position of unlabelled acetoacetyl­CoA on incubation wtih the enzyme. The acyl transferase activity eas studied using either [1­14C]­CoA and patethein as substrates or 14C­labelled CoA and acyl­CoA derivatives of varius chain length. A remarkable specificity was found for the transfer of the acetyl group. Thiolase activity and acyl transferase activity of the enzyme were diminished with the same kinetics during heat treatment or incubation with N ­ethylmaleeimide, ρ­cholomercuribenzoate or iodoacetamide. this indicates that both activities belong to the same protein. Inhibition of thiolase and acyltranferase activities by iodoacetamide (5 x 10­5 could be prevented by preicubation of the enzyme with acetoacetyl­CoA or acetyl­CoA. The acyl transfer is the rate determining step when the thiolase reaction operates in the direction of chain cleavage. Incubation of thiolase with acetyl­Coa results in binding of acetyl groups to the protein. The uptake of acetyl groups is dependent upon the specific activity of the enzyme and corresponds to 3 acetyl residues per molecule of protein (molecular weight 170,000) for the highest enzymatic activity obtained. both incorporation of acetyl groups into the enzyme and thiolase activity are inhibited to the same extent by iodoacetamide. the incorportion of radioactivity into the enztme during incubation with iodo­[1­14C]­acetamide can be divided into two different reactions: a fast incorporation with accompanying loss of enzymatic and a much slower process which continues after complete inactivation. From the initial rate of incorporation, it was calculaetd that incorporation of 3.1 carbamoylmethyl residues per molecule of protein would completely inhibit the enzyme withthe highest obtained activity. this ration cmpares well with the results obtained by acetyl binding studies and indicates a minimum of 3 active sites per molecule of enzyme. Enzyme labelled with iodo­[1­14C]acetamide was hydrolyzed with 6 N HCl. Approximately 95% of the radioactivity in the hydrolysate was found to coincide with S­carboxymethyl­L­cystine on electrophoresis and paper chromatography. Repeated crystallization with authentic carboxymethyl­cystine did not result in a decrease of specific radioactivity. [ABSTRACT FROM AUTHOR]

Spray water quality parameters such as hardness, pH, alkalinity, turbidity, and total dissolved solids (TDS) can influence the performance of herbicides. Polyvalent cations found in hard water can reduce the efficacy of post‐emergence herbicides that are weak acids. Various approaches have been proposed to mitigate the negative effects of spray water properties on herbicide performance. Water conditioning adjuvants are designed for overcoming the adverse effects of hard water. One group of adjuvants are nitrogen containing compounds such as ammonium sulfate (AMS). The ability of AMS to overcome hard water antagonism is well‐documented but the positive effect of other ammonium compounds are variable and depend on herbicides and weed species. Other adjuvant groups that can overcome effects of poor spray quality are ethoxylated amine surfactants, organic acids and ethylenediaminetetraacetic acid (EDTA). Water quality is poor in many parts of the world, and accordingly, the study of water property effects on herbicide performance is needed to optimize use, and prevent overuse, of herbicides. [ABSTRACT FROM AUTHOR]

Herein, the authors developed a new and potential semi‐interpenetrating polymer network (semi‐IPN) hydrogels of poly vinyl alcohol (PVA), acryl amide and diallyldimethyl ammonium chloride employing chemical cross‐linker N, N'‐methylene bisacrylamide (NNMBA) and ammonium persulphate as an initiator by radical polymerisation. To analyse the copolymer formation between two monomers and IPN cross‐linking reaction, the resulting hydrogel was characterised by Fourier transform infrared spectroscopy and the surface morphology was analysed using scanning electron microscopy. Differential scanning calorimetry and X‐ray diffraction studies were also carried out for investigating drug loading and distribution and swelling experiments were carried out for the uptake of water. In vitro release of ciprofloxacin hydrochloride from hydrogel was performed at intestinal conditions. The amount of PVA, NNMBA and total monomer concentration was found to strongly control the drug release behaviour from the hydrogels. [ABSTRACT FROM AUTHOR]

A thorough thermodynamic analysis by isothermal titration calorimetry of allosteric and chelate cooperativity effects in divalent crown ether/ammonium complexes is combined with DFT calculations including implicit solvent on the one hand and large-scale molecular dynamics simulations with explicit solvent molecules on the other. The complexes studied exhibit binding constants up to 2×106 m−1 with large multivalent binding enhancements and thus strong chelate cooperativity effects. Slight structural changes in the spacers, that is, the exchange of two ether oxygen atoms by two isoelectronic methylene groups, cause significantly stronger binding and substantially increased chelate cooperativity. The analysis is complemented by the examination of solvent effects and allosteric cooperativity. Such a detailed understanding of the binding processes will help to efficiently design and construct larger supramolecular architectures with multiple multivalent building blocks. [ABSTRACT FROM AUTHOR]

Peritonitis is a disease caused by bacterial strains that have become increasingly resistant to many antibiotics. The development of alternative therapeutic compounds is the focus of extensive research, so novel nanoparticles (NPs) with activity against antibiotic-resistant bacteria should be developed. In this study, the antibacterial activity of quaternary ammonium polyethyleneimine (QA-PEI) NPs was evaluated against Streptococcus viridans, Stenotrophomonas maltophilia and Escherichia coli. To appraise the antibacterial activity, minimal inhibitory concentration (MIC), minimal bactericidal concentration and bactericidal assays were utilised with different concentrations (1.56-100 μg/ml) of QA-PEI NPs. Moreover, 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) and annexin V/propidium iodide toxicity assays were performed in cell cultures. MICs for S. maltophilia and E. coli isolates were 12.5 and 25 μg/ml, respectively, whereas the MIC for S. viridans was 100 μg/ml. Furthermore, the growth curve assays revealed that these QA-PEI NPs at a concentration of 12.5 μg/ml significantly inhibited bacterial growth for the bacterial isolates studied. On the other hand, QA-PEI NPs lacked significant toxicity for cells when used at concentrations up to 50 μg/ml for 48 h. The present findings reveal the potential therapeutic value of this QA-PEI NPs as alternative antibacterial agents for peritonitis, especially against Gram-negative bacteria. [ABSTRACT FROM AUTHOR]

A detailed molecular understanding of the mechanisms of the dephosphorylation of phosphate triesters due to nucleophilic attack can be very useful for the design of nucleophiles that are more efficient. In this work, we report a combined experimental and theoretical study of the reaction of hydroxylamine with paraoxon. The profile of the reaction rate according to pH was determined, and it was found that protonated hydroxylamine was unreactive, while the neutral form reacted via the zwitterion tautomer, with an overall free energy barrier of 23.0 kcal mol‐1. The anionic form was the most reactive, with a free energy barrier of 18.1 kcal mol‐1. Computational calculations revealed 2 mechanisms for the nucleophilic attack of the zwitterion form: the usual backside attack and a new frontside attack mechanism. The former proceeded according to a 2‐step associative mechanism, while the latter was a concerted single‐step mechanism involving attack of the hydroxylamine oxygen on the phosphorus center and interaction of the NH3+ group with the oxygen of the P═O group. The calculations indicated that the free energy barrier for the frontside attack was more favorable than the backside attack by 3 kcal mol‐1, supporting the notion that the observed reaction occurs by frontside attack. The reaction with the anionic hydroxylamine form occurred according to a single‐step concerted ANDN mechanism. This paper presents a one‐step front side ANDN low‐barrier energy profile alternative route to the classic backside mechanism AN + DN for the dephosphorylation of paraoxon by hydroxylamine applying computational methods supported by experimental evidences. [ABSTRACT FROM AUTHOR]

Single crystals of tungsten double salt (NH4)3WO2F5 = (NH4)3[WO2F4]F have been synthesized by solid-state reaction or from fluoride solution and its crystal structures at 296 and 193 K were determined by X-ray diffraction. At room temperature, the crystal structure of the compound is dynamically disordered with the ligand atoms statistically distributed on two positions (6 e and 24 m) of the Pm3 m unit cell [ a = 6.0298 (1) Å], and the tungsten atom dynamically disordered on 12 orientations forming a spatial cuboctahedron [W12] that enables the real geometry of cis-WO2F4 octahedron to be determined with two short W-O distances. On cooling, the compound undergoes a first-order phase transition with the symmetry change Pm3 m→ Pa3 and a doubling of the unit-cell parameter [ a = 11.9635 (7) Å]. The ligand F(O) atoms statistically occupy two general 24 d sites and form W1 X6 and W2 X6 octahedra, in which the O and F atoms are not crystallographically different that means a static orientational disorder of (NH4)3WO2F5. [ABSTRACT FROM AUTHOR]

The asymmetric unit of the title salt, C12H24N+·C2H2BrO2−, contains a dicyclohexylammonium cation connected to a bromoacetate anion by means of an N-H...O hydrogen bond. In the crystal, the ion pairs assemble via N-H...O interactions, forming zigzag infinite chains parallel to the c axis with the (...H-N-H...O-C-O...) n motif that is considered to be a prerequisite for ensuring gelation properties of secondary ammonium monocarboxylate salts. The title salt was characterized by FT-IR, X-ray powder diffraction (XRPD), TG-DTA and 1H NMR spectroscopy in solution. Gelation experiments revealed that dicyclohexylammonium bromoacetate forms molecular gels with dimethylformamide and dimethyl sulfoxide. Scanning electron microscopy (SEM) was used to reveal morphological features of dried gels. [ABSTRACT FROM AUTHOR]

In the course of a study on artificial sweeteners, new crystal structures of cyclamic acid, sodium cyclamate, potassium cyclamate, ammonium cyclamate, rubidium cyclamate and tetra- n-propylammonium cyclamate have been determined. Cyclamic acid exists in its zwitterionic form in the crystalline state. The zwitterions are connected through hydrogen bonds of the N—H...O type to form two-dimensional sheets. The sodium, potassium, ammonium and rubidium cyclamates are isostructural, with the cyclamate moieties linked through hydrogen bonds into linear chains. Taking into account the connectivity through cations, two-dimensional layers with a hydrophobic surface are constructed. In tetra( n-propyl)ammonium cyclamate the large, non-coordinating cation apparently prevents the formation of chains and thereby facilitates the centrosymmetric head-to-head discrete dimeric arrangement of the cyclamate moieties. [ABSTRACT FROM AUTHOR]

Recently, a population of nerves has been described in the aganglionic mouse vas deferens, in which electrically evoked contractions were insensitive to high concentrations of the adrenergic neurone blocker, bretylium. In this paper, the pharmacology of this nerve-evoked contraction has been examined in more detail.Bretylium (20 μM) revealed, after 5 h exposure, a new residual neurogenic contraction (20 stimuli at 10 Hz) that was tetrodotoxin-sensitive.The muscarinic antagonist, cyclopentolate (0.1 and 1 μM), reduced this residual component and the inhibition was reversed by the acetylcholinesterase inhibitor, neostigmine (1 and 10 μM).Nicotine (30 μM) enhanced the residual component revealed by bretylium, suggesting that there are prejunctional nicotinic receptors (nAchRs) influencing acetylcholine (Ach) release.In the presence of prazosin (0.1 μM), a selective α1-adrenoceptor antagonist, and α,β-methylene ATP (1 μM), a purinergic agonist that desensitise P2X receptors, neostigmine increased the hump component of contraction and yohimbine (0.3 μM), an α2-adrenoceptor antagonist, enhanced both components of the electrically evoked stimulation. The contraction was blocked by cyclopentolate (1 μM).In the absence of bretylium, neostigmine alone increased the hump component of contraction in a frequency-dependent manner. This increase was reversed by atropine (1 μM) and cyclopentolate (1 μM) to control levels. However, in control experiments, atropine or cyclopentolate did not detectably influence the delayed neurogenic contraction.Ach (10 μM) induced a contraction in the mouse vas deferens, either when applied alone or in the presence of neostigmine.Thus, it has been demonstrated unequivocally that the mouse vas deferens is innervated by functional cholinergic nerves, whose action is terminated by cholinesterase. Furthermore, Ach release can be enhanced by activation of prejunctional nAchRs presumably located on the cholinergic nerve terminals.British Journal of Pharmacology (2005) 146, 927–934. doi:10.1038/sj.bjp.0706357; published online 19 September 2005 [ABSTRACT FROM AUTHOR]

The structures of six 1-phenylethylammonium tartrates have been determined and in each of them a distinctive hydrogenbonded anion substructure can be identified. (S)-l-Phenylethylammonium (R,R)-hydrogen tartrate [(I), P21, Z'= 1] contains anion sheets built from a single type of R44(22) ring with cations pendent, via three N-H…O hydrogen bonds, from just one face of the sheet. (S)-l-Phenylethylammonium rac-hydrogen tartrate [(II), P21, Z' = 2] and its enantiomorph (R)-l-phenylethylammonium rac-hydrogen tartrate [(III), P21, Z'= 2] contain anion sheets built from four types of ring, R2²(10), R2²(12), R24(14) and R44(20), and there are cations pendent from both faces of the sheet. The anion substructure in bis[(S)-l-phenylethylammonium] (R,R)-tartrate [(IV), P21, Z' = 1] consists of simple C(5) chains, which are linked into sheets by the cations, while in bis(rac-l-phenylethylammonium) (R,R)-tartrate [(V), P21, Z' = 2] there are anion sheets containing two distinct types of R44(22) ring, with equal numbers of (R) and (S) cations pendent from each face of the anion sheet. Bis[(R)-l-phenylethylammonium] rac-tartrate methanol hemisolvate [(VI), P1, Z' = 4, with 14 independent components in the asymmetric unit] contains anion sheets built from two types of R2²(12) ring and two types of R66(32) ring; half of the cations and half of the methanol molecules are pendent from each face of the sheet. [ABSTRACT FROM AUTHOR]

Assimilation of 15N-ammonium and 15N-nitrate was examined in 3-year-old satsuma mandarin (Citrus unshiu Marcovitch) trees. Experiments were designed to establish the time course of incorporation of nitrogen just taken up into amino compounds. In fine roots, absorbed 15N-ammonium was actively incorporated into glutamine and then into glutamic acid and asparagine. When feeding 15N-nitrate, glutamic acid and asparagine were actively synthesized, but glutamine synthesis was comparatively low as compared with that in ammonium feeding. In current leaves and fruits, a clear difference in the labelling patterns of amino acids was found between the ammonium and nitrate feedings. The amino acid most markedly labelled was asparagine in the ammonium feeding and glutamine in the nitrate feeding. Considering the most heavily labelled component in leaves and fruits, the main form of the nitrogen components transported upward in the xylem was discussed. [ABSTRACT FROM AUTHOR]

Carboxypeptidase Aγ from porcine pancreas was purified to homogeneity by ammonium sulfate fractionation, autolysis, batch absorption and elution from DEAE-Sephadex, and crystallization. The overall purification was about 32-fold with a yield of 31% and the specific activity of the purified protein was 108 units/mg protein. The apparent relative molecular mass determined by gel filtration on a Sephadex G-200 column was 38 900. The amino-terminal sequence of the porcine carboxypeptidase Aγ was Asn-Tyr-Ala-Thr-Tyr-His-Thr-Leu-Glu- Glu-Ile-Tyr-Asp-Phe-Met-Asp-Ile-Leu-Val-Ala-Glu-His-Pro-Gln-Leu- which was highly homologous to that of bovine carboxypeptidase Aγ. The purified enzyme was characterized with respect to isoelectric point (4.3). K[subm] for N[supα]-carbobenzoxyglycyl-L-phenylalanine (Cbz-Gly-LPhe) (20 mM), amino acid composition, pH optimum, pH stability, stability at different temperatures and effect of drying. The enzyme contained 1.01 mol zinc/mol and was inhibited by chelating agents such as EDTA and o-phenanthroline. Among substrates such as Cbz-Gly-LPhe, N[supα]-benzoylglycyl-L-arginine, various kinds of amino acid esters, casein and elastin, porcine carboxypeptidase AAγ showed an enzymatic activity only towards Cbz-Gly-LPhe and casein. These data are in good agreement with the substrate specificity of bovine carboxypeptidase A. [ABSTRACT FROM AUTHOR]

Horse ribonuclease was purified after acid extraction of pancreas by ammonium sulfate fractionation and chromatography on CM-cellulose. It is a glycoprotein with an average molecular weight of about 18 000. The pure enzyme was chromatographically and electrophoretically heterogeneous due to the heterogeneity of the carbohydrate moiety. The amino-acid sequence was determined from four series of peptides obtained by different cleavage methods. All but four peptide bonds were overlapped by one or more peptides. The polypeptide chain contains 125 amino-acid residues and carries oligosaccharide side-chains at positions 21, 34, and 62; part of Asn-21 occurs in the carbohydrate-free form. There are two additional amino acids at the C-terminus and a deletion at position 39. Including these, horse ribonuclease differs in 35 positions from the bovine enzyme. Horse ribonuclease is more closely related to the artiodactyl ribonucleases than is the rat enzyme. Except for the deletion, all differences can be accommodated in the three-dimensional model of bovine ribonuclease-S without altering the folding of the backbone. Model building of the loop containing the deletion offered an explanation for the deviating titration behavior of one of the tyrosine residues in horse ribonuclease. [ABSTRACT FROM AUTHOR]

A practical straightforward synthesis of medicinally important NH‐δ‐lactams through the three‐component Castagnoli‐Cushman reaction of 3‐arylglutaconic anhydrides with carbonyl compound and ammonium acetate has been developed. The scope of the protocol has been thoroughly explored paying particular attention to the carbonyl component using wide array of aliphatic and aromatic aldehydes as well as rarely involved cyclic and acyclic ketones. Synthetic potential of prepared compounds was demonstrated by a series of post‐modifications, including unexpected isomerization. [ABSTRACT FROM AUTHOR]

BACKGROUND: The so‐called 'Neapolitan limmo' or 'lemoncetta Locrese' is an old and now rare Mediterranean sweet lime, similar to lemon but smaller. It is a fruit distinguished from orange, lemon, mandarin, and lime for its sweeter, watery, and non‐acidic taste, with a pH between 5.6 and 5.9. No compositional studies are currently available for this citrus fruit. Here we report, for the first time, the distribution in the limmo juice of free amino acids and their main derivatives such as betaines and related ammonium compounds. RESULTS: Seven proteinogenic amino acids (proline, asparagine, serine, aspartic acid, glutamine, alanine, and threonine) and a non‐protein amino acid (γ‐aminobutyric acid) characterize Neapolitan limmo juice. Proline betaine is the predominant betaine. The data were compared with those of other important citrus juices. CONCLUSION: The specific 'taste quality' of Neapolitan limmo juice can be attributed to its peculiar composition in amino acids. The species‐specific presence of the ammonium compound derivatives of the amino acid proline, with proline betaine as the predominant betaine, characterize the non‐acidic varieties of Mediterranean sweet lime. Our study constitutes an important step towards the repopulation of this ancient plant and its exploitation in food industry. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The black-eyed pea trypsin and chymotrypsin inhibitor (BTCI) is a Bowman-Birk-type inhibitor from Vigna unguiculata seeds. A complex of BTCI with bovine β-trypsin was crystallized by the hanging-drop vapour-diffusion method with ammonium sulfate as precipitant. Crystals belong to the orthorhombic space group P2[SUB1]2[SUB1]2[SUB1], with unit-cell parameters a = 59.3, b =61.8, c = 80.0 Å. Diffraction data were collected to 2.36 Å resolution and were processed to give an overall R[SUBsym] of 0.137. The Matthews coefficient for one complex per asymmetric unit is 2.2 Å[SUP3] Da[SUP-1], with a corresponding solvent content of 43%. After molecular replacement and initial refinement, the model given an R[SUBeryst] of 0.361 and an R[SUBfree] of 0.432. [ABSTRACT FROM AUTHOR]

The article presents information on the purification, crystallization and preliminary X-ray crystallographic analysis of human CCG1-interacting factor B. Thin plate-like crystals were grown using ammonium sulfate as the primary precipitant. As the CIB protein always precipitated in the presence of ammonium sulfate alone, an additional additive was essential along with ammonium sulfate to initiate the nucleation process.

The complex between Thermus thermophilus prolyl-tRNA synthetase (ProRSTT) and its cognate tRNA has been crystallized using two different isoacceptors of tRNAPro. Similar bipyramidal crystals of the complexes of ProRSTT with the two different tRNA Pro isoacceptors grow within two weeks from 32% saturated ammonium sulfate solution. They belong to space group P43212, with unit-cell parameters a = 143.1, b = 143.1, c = 228.6 Å. The crystals diffract weakly to a maximum resolution of 3.1 Å. Superior quality crystals were obtained by growing slowly from precipitate over 5-6 months. These are of the same space group but have slightly altered unit-cell parameters, a = 140.8, b = 140.8, c = 237.0 Å. These crystals diffract more strongly to at least 2.8 Å resolution and a complete data set to 2.85 Å resolution has been collected from a single crystal. Comparison of the packing in the two crystal forms shows that domain flexibility contributes to the presence of different crystal contacts in the two forms. [ABSTRACT FROM AUTHOR]

Novel gemini (tail‐head‐spacer‐head‐tail) bis‐quaternary ammonium compounds (bis‐QACs) with a biphenyl spacer between two pyridinium heads were synthesized and compared with commonly used antiseptics such as benzalkonium chloride (BAC) and chlorhexidine digluconate (CHG). The series of compounds showed high inhibitory activity against five bacterial strains and two fungi. The compounds, which contain C8H17‐C10H21 aliphatic tails best within the series. A counterion change does not affect MIC in general. Cytotoxicity on human embryonic kidney cells and haemolysis were also investigated. For bis‐QACs cytotoxic effect was lower than for 3,3′‐[1,4‐phenylenebis(oxy)]bis(1‐dodecylpyridinium) dibromide (3PHBO‐12), that is their closest structural analogue, and for BAC. [ABSTRACT FROM AUTHOR]

Thermomechanical pulp (TMP) was pretreated with ammonium polyphosphate (APP) to improve the fire retardancy of extruded thermoplastic composites for facades. In addition, APP was also added during compounding to protect the polymer matrix. The limiting oxygen index (LOI) value of the composites was significantly increased when APP was added during compounding. The additional TMP pretreatment leads to a further increase of the LOI, which resulted in a maximum value of 35% indicating the self‐extinguishing behavior of the material. Compared to untreated TMP, thermal stability of pretreated TMP was lower up to a temperature of ~250 °C which was attributed to the formation of polyphosphoric acid, which catalyzes the degradation of cellulose. Upon formation of a char layer, thermal stability of pretreated TMP was increased compared to untreated TMP. Tensile strength of composites based on pretreated TMP was slightly reduced compared to untreated TMP while tensile modulus of elasticity (MOE) was unaffected. Swelling and water uptake of the composites was increased due to the use of APP during compounding but the fiber pretreatment did not lead to any further increase. The single flame source test showed that the formulations which included APP were self‐extinguishing even when an extended flame treatment of 300 s (normally: 30 s, according to EN ISO 11925‐2) was applied. The fire shaft test was not passed for extruded profiles based on pretreated TMP; however, its conditions are more severe than those of the single‐burning item (SBI) test. POLYM. COMPOS., 40:2410–2423, 2019. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

We report on the structural and luminescence properties of a series of d10 dicyanometallate compounds of formula K3(Me4N)2[M(CN)2]5 (M = Au and Ag). These double salts form isostructural 3D networks in which metallophilic bonding is observed between [M(CN)2]– subunits. Despite their similar structural features, stark differences in luminescence behavior between these crystals are observed. At room temperature Au‐containing crystals are bright emitters at 405 nm while the Ag analog is a weak emitter at 470 nm. At low temperatures the emission of both complexes becomes intense under UV light at a wavelength of 416 nm. Using lifetime measurements, X‐ray crystallography, and Density Functional Theory (DFT) calculations we have been able to assign these emission bands as a transition from a metal‐metal to ligand charge transfer. Networks of [Au(CN)2]– and [Ag(CN)2]– using the cation tetramethylammonium are structurally and photophysical characterized. Temperature‐ and time‐dependent luminescence, supported with DFT calculations, indicate a temperature dependent dual fluorescence/phosphorescence emission pathway in the case of Au. [ABSTRACT FROM AUTHOR]

Methylammonium lead trihalides and their derivatives are photovoltaic materials. CH3NH3PbI3 is the most efficient light harvester among all the known halide perovskites (PSCs). It is regarded as unsuitable for long‐term stable solar cells, thus it is necessary to develop other types of PSC materials to achieve stable PSCs (Wang et al., Nat. Energy 2016, 2, 16195). Because of this, various research efforts are on‐going to discover novel lead‐based or lead‐free single/double PSCs, which can be stable, synthesizable, transportable, abundant and efficient in solar energy conversion. Keeping these factors in mind, we report here the electronic structures, energetic stabilities and some materials properties (viz. band structures, density of states spectra and photo‐carrier masses) of the PSC chloroammonium lead triiodide (ClNH3PbI3). This emerges through compositional engineering that often focuses on B‐ and Y‐site substitutions within the domain of the BMY3 PSC stoichiometry. ClNH3PbI3 is found to be stable as orthorhombic and pseudocubic polymorphs, which are analogous with the low and high temperature polymorphs of CH3NH3PbI3. The bandgap of ClNH3PbI3 (values between 1.28 and 1.60 eV) is found to be comparable with that of CH3NH3PbI3, (1.58 eV), both obtained with periodic DFT at the PBE level of theory. Spin orbit coupling is shown to have a pronounced effect on both the magnitude and character of the bandgap. The computed results show that ClNH3PbI3 may act as a competitor for CH3NH3PbI3 for photovoltaics. © 2018 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Abstract: 3,4‐Dihydroxybenzhydrazide (DHBH) could be considered a structural analogue of dopamine, forming polymers under oxidative conditions in a polydopamine (PDA) fashion. However, the former turns out to be more reluctant to oxidize and thus, more drastic conditions must be applied to achieve polymerization. Heating of DHBH in the presence of ammonium peroxydisulfate in Tris buffer yields a mixture of oligomers (average 9–10 monomer units). Although it looks black like PDA, its structure is very different. The polymer is not built up by CC bond formation but by replacement of hydroxyl groups resulting in acylhydrazine, acylhydrazone, and 1,3,4‐oxadiazoline bridging. Since the catechol moiety of the starting material is destroyed, the polymer lacks the mussel‐like anchoring property found in PDA. [ABSTRACT FROM AUTHOR]

Abstract: Earth‐abundant first‐row transition‐metal nanoclusters (NCs) have been extensively investigated as catalysts. However, their catalytic activity is relatively low compared with noble metal NCs. Enhanced catalytic activity of cobalt NCs can be achieved by encapsulating Co NCs in soluble porous coordination cages (PCCs). Two cages, PCC‐2a and 2b, possess almost identical cavity in shape and size, while PCC‐2a has five times more net charges than PCC‐2b. Co2+ cations were accumulated in PCC‐2a and reduced to ultra‐small Co NCs in situ, while for PCC‐2b, only bulky Co particles were formed. As a result, Co NCs@PCC‐2a accomplished the highest catalytic activity in the hydrolysis of ammonium borane among all the first‐row transition‐metals NCs. Based on these results, it is envisioned that confining in the charged porous coordination cage could be a novel route for the synthesis of ultra‐small NCs with extraordinary properties. [ABSTRACT FROM AUTHOR]

Abstract: Streptococcosis is an important bacterial disease in Nile tilapia causing severe economic losses to tilapia aquaculture worldwide. The effects of water quality (low‐ [LS] and high‐level [HS] soiling, to mimic clean or dirty surface conditions and temperatures) and disinfectant application (diluted concentrations and exposure time) were characterized on the inactivation of Streptococcus agalactiae isolated from diseased tilapia. Five isolates were tested against three commercial disinfectant products with the main ingredients being povidone iodine (Anidine 100™; AD), benzalkonium chloride (Better BKC 80%™; BKC 80), and a mixture of quaternary ammonium compounds and glutaraldehyde (Chloraldehyde™; CR). CR demonstrated highest efficacy to S. agalactiae inactivation, followed by BKC 80 and AD, respectively. Higher‐level soiling, low temperature, diluted concentrations and short exposure time all decreased the disinfectant efficacy. CR and BKC 80 provided more than 5‐log inactivation at 1‐min exposure at 20°C under HS conditions, and also with ten‐fold‐diluted concentrations at 60‐min exposure time at 30°C. However, AD required 10‐min exposure to effectively remove bacteria under LS conditions at 30°C. The results could facilitate aquaculture management planning that leads to operating cost reductions and improvements in biosecurity. [ABSTRACT FROM AUTHOR]

Crosslinked hydroxyl-conductive copolymer/silica composite membranes based on addition-type polynorbornene, poly(dodoxymethylene norbornene-co-norbornene-3-(trimethylpropyl ammonium)-functionalized silica (QP(DNB/NB-SiO2), were prepared by a sol-gel method. Copolymer composite membranes with different degree of quaternary ammonium functional silica, designated as QP(DNB/NB-SiO2-X) ( X = 5, 10, 15 and 25 wt%, respectively), displayed good dimensional stabilities with low in-plane swelling rate of 1.32-3.7%, good mechanical properties with high elastic modulus of 605.4-756.8 MPa and high tensile strength of 13.2-20 Mpa. The achieved copolymer composite membranes could self-assemble into a microphase-separated morphology with randomly oriented long-range aliphatic chain/cylinder ionic channels that were imbedded in the hydrophobic PNB matrix. Among these membranes, the QP(DNB/NB-SiO2-25) showed the parameter with ionic conductivity of 9.33 × 10−3S cm−1, methanol permeability of 2.89 × 10−7cm2 s−1, and ion-exchange capacity(IEC) of 1.19 × 10−3 mol g−1. A current density of 82.3mA cm−2, the open circuit voltage of 0.65 V and a peek power density of 32 mW cm−2 were obtained. POLYM. ENG. SCI., 58:13-21, 2018. © 2017 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

The synthesis of an organoammonium diphosphopentamolybdates(VI), (C6H14N)5[HP2Mo5O23]·4H2O (1), is reportet. The molecular structure and spectroscopic analysis were performed using experimental techniques like X-ray diffraction, FT-IR, and UV/Vis. The single crystal analysis of the title compound shows that the compound crystallizes in the monoclinic crystal system with space group P21/c and cell constants of a = 12.7934(2) Å, b = 14.8145(2) Å, c = 27.2637(5) Å, and β = 92.9298(14)°. The Hirshfeld surfaces and the associated 2D fingerprint plots were investigated to study the intermolecular interactions in the crystal packing and this study has confirmed that the hydrogen bonding interactions play a dominating role in the stability of crystal structure. The theoretical calculations were done using PM3 semi-empirical model and several properties were studied. [ABSTRACT FROM AUTHOR]

Three ammonium-cationic zeolites (ferrierite, ZSM5, and zeolite BETA) are individually analyzed to produce branched-chain fatty acid (i.e., isostearic acid) from unsaturated linear-chain fatty acid (ulc-FA) with up to 98% conversion and 80% selectivity. The SiO2/Al2O3 molar ratio of zeolite, amount of water and choice of additive are found to be the key factors for the efficiency of zeolites in this particular reaction. Detailed characterization of zeolites supports the optimization parameters to produce the best results. Large scale production of isostearic acid achieving a 76% selectivity and 96% conversion demonstrates the potential of this system's capability at the pilot scale. Variation in isomeric composition of branched-chain fatty acid (bc-FA) product is observed for the three different catalytic methods. Dimer production due to interaction with the external acidic surface of these zeolites has been observed, but it can be suppressed. Practical Application: Lubricant, cosmetic and surfactant fields are examples where these biodegradable isostearic acid and other bc-FA materials are applied. Three ammonium cationic zeolites (i.e., ferrierite, BETA, ZSM-5) are used to produce the iso-oleic acid (precursor of isostearic acid) with high selectivity. The iso-oleic acid products are found to have different isomeric compositions which could potentially expand the application of the isostearic acid. [ABSTRACT FROM AUTHOR]

ABSTRACT To increase the encapsulation efficiency of microcapsules composed of water-soluble salt cores and hydrophobic material shells, we herein reported a facile and versatile strategy to improve the hydrophobicity of water-soluble salts [i.e., ammonium persulfate (APS)] by surface modification of APS using oleic acid or silane coupling agent, respectively. The results confirmed that the hydrophobicity of the two modified APS had been successfully improved compared with that of non-modified APS. Moreover, the two modified APS could be effectively encapsulated into hydrophobic polystyrene and the encapsulation efficiency of the resulting microcapsules goes up significantly. This study was expected to drive progress in the preparation technology of microcapsules which comprise water-soluble salts as cores and hydrophobic polymer materials as shells in many industrial application fields. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45294. [ABSTRACT FROM AUTHOR]

A study of the phase transitions occurring in tetramethylammonium hexachlorometalate compounds with M = UIV, NpIV, ZrIV, SnIV, HfIV, and PtIV were performed using singlecrystal X-ray diffraction across the temperature range 120-400 K. When the crystals are cooled, movement of the octahedral [MCl6]2- anions induces a phase transition from Fm3m to Fd3c with a doubling of the unit cell. For the actinide compounds, no correlation between the f-electron configuration and the transition temperature was observed; instead, a correlation between the transition temperatures and both the [MCl6]2- anion and the TMA cation size is highlighted. Two phase transitions were observed and characterized. The first phase transition occurs with the ordering of the TMA cation and the second from a rotation of the [MCl6]2- octahedra. A third phase transition was observed at lower temperatures and was ascribed to a tetragonal distortion of the [MCl6]2- anions. Synthesis and study of the deuterated compounds did not show a significant isotope effect. Raman spectra of the protonated and deuterated compounds indicate only weak hydrogen bonding interactions between the TMA cations and the [MCl6]2- octahedra. [ABSTRACT FROM AUTHOR]

The plant-availability of phosphorus (P) in fertilizers and soil can strongly influence the yield of agricultural crops. However, there are no methods to efficiently and satisfactorily analyze the plant-availability of P in sewage sludge-based P fertilizers except by undertaking time-consuming and complex pot or field experiments. We employed the diffusive gradients in thin films (DGT) technique to quantify the plant P availability of various types of P fertilizers with a novel focus on sewage sludge-based P fertilizers. Mixtures of fertilizer and soil were incubated for 3 weeks at 60% water holding capacity. DGT devices were deployed at the beginning of the incubation and again after 1, 2, and 3 weeks. Two weeks of incubation were sufficient for the formation of plant-available P in the fertilizer/soil mixtures. In a pot experiment, the DGT technique predicted maize ( Zea mays L.) biomass yield and P uptake significantly more accurately than standard chemical extraction tests for P fertilizers ( e.g., water, citric acid, and neutral ammonium citrate). Therefore, the DGT technique can be recommended as a reliable and robust method to screen the performance of different types of sewage sludge-based P fertilizers for maize cultivation minimizing the need for time-consuming and costly pot or field experiments. [ABSTRACT FROM AUTHOR]

Despite the rapid reaction rates and high efficiency of the radical-mediated thiol-ene reactions in high concentrations, complications arise when implementing this reaction under dilute conditions, such as those often requisite for polymer-polymer conjugation. Here, we briefly review some of the challenges inherent in polymer modification via thiol-ene reactions and demonstrate several successful polymer couplings (including star polymer assembly) under a variety of conditions with coupling efficiencies exceeding 91% achieved with appropriate initiator and terminal functional group selection. Generally, the results indicate thermal initiation with an 'azobis' initiator was unsuccessful in polymer-polymer conjugation of a thiol-terminated poly(ethylene glycol) (PEG) to an alkene terminated PEG. Reduction-oxidation initiators, both ammonium persulfate and Fe(II) and Fenton's reagent were effective in conjugating thiol terminated PEG to norbornene terminated PEG, but not to an allyl ether terminated PEG. Type I photoinitiators, in particular a water soluble acyl phosphinate, were more effective than either the examined thermal or redox initiators for thiol-ene polymer-polymer conjugations generally. [ABSTRACT FROM AUTHOR]

Ammonium polyphosphate (APP) and inorganic fillers were applied for improving flame retardancy and mechanical performance of recycled poly(ethylene terephthalate) (RPET). RPET was compounded with 5-10 wt% of talc and glass bead using twin screw extruder then were injection molded with 2 wt% of APP. The effects of fillers contents and APP on properties and flame retardancy of RPET composites were investigated. The incorporation of talc and glass bead as well as the adding of APP significantly improved tensile and flexural modulus of RPET composites. Scanning electron microscope micrographs indicated good distribution of talc, while glass bead was agglomerated on the RPET matrix. Flame-retardant property of neat RPET and the RPET composites revealed V-2 of UL-94 flammability rating. It can be noted that the composites were less dripping because of the synergistic effect of adding talc and glass bead with APP. From thermogravimetric analysis results, larger of residual char contents and lower values of the activation energy were considered for enhancing flame retardancy in the RPET composites. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Ethanol is shown to act as a hydrogenating agent for ynamides under palladium catalysis. This behavior is different from the normally expected reaction of ethanol addition to alkynes. The reaction shows stereoselectivity for E enamides, which is in contrast to reports using other hydrogenating sources. The method was also extended to ynamines. Alternatively, the use of ethanol and ammonium formate as the hydrogenating source gives Z enamides. The role of ethanol in hydrogenation was demonstrated by means deuterium labeling experiment. [ABSTRACT FROM AUTHOR]

The effects of different n-alkanol co-surfactants on the size, shape, composition and dynamics of reverse micelles (RMs) in cetyltrimethylammonium bromide (CTAB)/n-alkanol/n-hexane/water and CTAB/n-alkanol/n-pentane/water microemulsions were investigated using T2 relaxation and pulsed gradient stimulated echo nuclear magnetic resonance (NMR) measurements and molecular modelling. NMR T2 relaxation times and diffusion coefficients were determined for the surfactant and co-surfactant in these CTAB quaternary reverse microemulsions, for a range of medium chain length alcohol co-surfactants, from 1-butanol to 1-heptanol. These data revealed a slight RM size dependency on co-surfactant chain length, with RM sizes tending to decrease with increasing alcohol chain length. Molecular modelling of CTAB/n-alkanol/n-hexane/water RMs suggested a variation in RM shape with co-surfactant chain length, where those formed with pentanol were found to be least spherical and those formed with heptanol the most spherical. The NMR data also revealed differences in the behaviour of the micellar structures in the CTAB/n-pentanol/n-hexane/water reverse microemulsion, compared with the other reverse microemulsions in this study, where CTAB was found to be distributed between two environments, which then combined to form larger micelles. The origins of these differences remain unclear. [ABSTRACT FROM AUTHOR]