Synthesis of polymer materials by low energy electron beam. VIII. Formation mechanism of microporous urethane-acrylamide film

The formation mechanism of microporous film which was obtained by casting a methyl ethyl ketone (MEK)/N,N-dimethlformamide (DMF) solution of an electron beam (EB)-reactive urethane-acrylamide prepolymer was discussed. The porosity and crystallinity increased with increasing DMF content in the solvent mixture. This correlation was explained by a progressive slight coagulation and nucleation of the prepolymer due to the difference in volatility between MEK and DMF. As the result, when the DMF content reached 25 vol%, micropores were formed throughout the film. Such a mechanism was supported by the localization of the acrylamide groups at the surface which was induced by the crystallization and by the interaction of amide groups with DMF. The polymerization of acrylamide groups by EB could fix the microporous morphology.     

Fluxional behavior of Al(Et)(q)2 (q=2-methyl-8-quinolinolato) studied by temperature dependent H NMR spectroscopy

Two α-CH₂ hydrogens of the Et group in Al(Et)(q^′)₂ (q^′=2-methyl-8-quinolinolato) show two ¹H NMR peaks at different positions with a separation of 0.19 ppm at 25 °C, due to the presence of a chiral center at Al. On raising the temperature, the two peaks collapsed, and coalesced above 100 °C. The ¹H NMR fluxional behavior is accounted for by simultaneous rotation of the q^′ ligands, and kinetic parameters of kJ mol⁻¹, kJ mol⁻¹, J K⁻¹ mol⁻¹ are evaluated.     

A Novel Glucose Biosensor Based on Palladium Nanoparticles and Its Application in Detection of Glucose Level in Urine

IntroductionThelevelofglucoseinbloodorurineindicateshyper andhypoglycaemia ,bothofwhichcanresultfromavarietyofendocrinedisorders .1 4 Therapidandreliabledetermi nationofglucoselevelisaroutineprojectinclinicchem istry.Urinesamplesaresaferandmoreconvenientthanbloodones .Meanwhile ,theconcentrationofglucoseinserumiscloselyassociatedwiththatinurine .2 4 Eventhoughglucoseelectrodeshavebeensuccessfullyusedinseruminclinicalapplication ,thequestionstillremainedofhowtodetecttheglucoselevelinurine ,wh…     

Preparation of a new receptor for anions, macrocyclic polythiolactam—structure and high anion-binding ability

Thiocarbonylation of a macrocyclic tetralactam gave a new macrocyclic tetrathiolactam. The chemical transformation enhances hydrogen-bonding ability of the NH protons in the cavity of the macrocycle, and provides strong affinity toward anions. The association properties of the polythiolactam with anions was examined, and molecular structures of the macrocycle and its Cl⁻ complex were determined.     

Reductive elimination of C6F5-C6F5 in the reaction of bis(pentafluorophenyl)palladium(II) complexes with protic acids

Reductive elimination of C6F5-C6F5 from cis-[Pd(C6F5)2L] (L = cod, bpy, and dppb) was promoted by Br?nsted acids. HNO3 is a convenient acid for the formation of C6F5-C6F5 from [Pd(C6F5)2(cod)]. The products are controlled by the auxiliary ligand.     

Homocoupling of aryl halides promoted by an NiCl2/bpy/Mg system in DMF

Homocoupling of aryl halides (2 ArX → Ar―Ar) promoted by NiCl₂/2,2′‐bipyridine (bpy)/Mg mixtures in DMF has been studied. Mixtures of NiCl₂, bpy and Mg in DMF promoted homocoupling of aryl halides such as phenyl bromide and p‐tolyl bromide to give the coupling products in good (e.g. approximately 60–75%) yields, and the homocoupling products were easily isolated from the reaction mixtures. Application of this homocoupling to dibromo‐aromatic compounds (Br–arylene–Br: 2,5‐dibromopyridine, 2,7‐dibromo‐9.9‐dioctylfluorene and 2,7‐dibromo‐9,10‐dioctyl‐9,10‐dihydrophenanthrene) gave the corresponding π‐conjugated polymers, –(arylene)_n–, in good yields. Organometallic processes for the homocoupling are discussed. Copyright © 2014 John Wiley & Sons, Ltd.     

Ether-Functionalized Pyrrolidinium-Based Room Temperature Ionic Liquids: Physicochemical Properties,Molecular Dynamics,and the Lithium Ion Coordination Environment

The physicochemical properties of room temperature ionic liquids (RTILs) consisting of bis(trifluoromethanesulfonyl)amide (TFSA⁻) combined with 1-hexyl-1-methylpyrrolidinium (Pyr_1,6⁺), 1-(butoxymethyl)-1-methylpyrrolidinium (Pyr_1,1O4⁺), 1-(4-methoxybutyl)-1-methyl pyrrolidinium (Pyr_1,4O1⁺), and 1-((2-methoxyethoxy)methyl)-1-methylpyrrolidinium (Pyr_1,1O2O1⁺) were investigated using both experimental and computational approaches. Pyr_1,1O2O1TFSA, which contains two ether oxygen atoms, showed the lowest viscosity, and the relationship between its physicochemical properties and the position and number of the ether oxygen atoms was discussed by a careful comparison with Pyr_1,1O4TFSA and Pyr_1,4O1TFSA. Ab initio calculations revealed the conformational flexibility of the side chain containing the ether oxygen atoms. In addition, molecular dynamics (MD) calculations suggested that the ion distributions have a significant impact on the transport properties. Furthermore, the coordination environments of the Li ions in the RTILs were evaluated using Raman spectroscopy, which was supported by MD calculations using 1000 ion pairs. The presented results will be valuable for the design of functionalized RTILs for various applications.     

Radical-scavenging activities of new megastigmane glucosides from Macaranga tanarius (L.) MULL.-ARG

Four new megastigmane glucosides, named macarangiosides A-D (2-5), together with mallophenol B, lauroside E, methyl brevifolin carboxylate, and hyperin and isoquercitrin as a mixture were isolated from the leaves of Macaranga tanarius (L.) MULL.-ARG. (Euphorbiaceae). Their structures were elucidated by spectroscopic and chemical analyses. Macarangioside A-C (2-4) and mallophenol B were galloylated on glucose moiety and possessed the potent 2,2-diphenyl-picrylhydrazyl (DPPH) radical-scavenging activity.     

Synthesis, structure, and quaternization and complexation reactions of κSCS pincer palladium complexes having 3,5-pyridinediyl unit

The cyclopalladation of 3,5-bis(diphenylphosphinothioyl)pyridine afforded new κ³S,C,S-pincer palladium complexes with a σ-bond between Pd and 4C of the centered 3,5-pyridinediyl unit. By utilizing the quaternization and complexation ability of the pyridine imine nitrogen (N_py) atom, various new pincer-type complexes, including hetero-binuclear complexes, have been synthesized.