A Molecular Ferroelectric Thin Film of Imidazolium Perchlorate That Shows Superior Electromechanical Coupling

Molecular ferroelectric thin films are highly desirable for their easy and environmentally friendly processing, light weight, and mechanical flexibility. A thin film of imidazolium perchlorate processed from aqueous solution is an excellent molecular ferroelectric with high spontaneous polarization, high Curie temperature, low coercivity, and superior electromechanical coupling. These attributes make it a molecular alternative to perovskite ferroelectric films in sensing, actuation, data storage, electro‐optics, and molecular/flexible electronics.     

Preparation and characterization of a conductive polyaniline/polysulfone film and evaluation of the effect of co-solvent

A novel conductive dense membrane composed of polyaniline (PANI) and polysulfone (PSU) was prepared. To improve the solubility of PANI in N-methyl pyrrolidone (NMP) and consequently increase the conductivity of the eventual film, a tertiary amine (1,3-dimethyl-2-imidazolidinone, DMI) was added to the solvent as a co-solvent. Different PANI solution concentrations in NMP/DMI were used to make blend films via solution blending with PSU solution in NMP in different ratio’s of PANI/PSU. The effect of the PSU fraction on the properties of the membrane has been investigated. The electrical conductivity, doping degree, crystallinity, miscibility of the polymers and shape stability were investigated. It was observed that an increase in the PSU fraction causes a decrease in the conductivity as well as less film deformation after doping. The conductivity and shape stability of the blend film were optimized by a change in PANI concentration in the casting solution and a change in the PSU fraction. The best conductivity was achieved using 3% PANI solution in NMP/DMI and the minimum percentage of PSU, allowing good shape stability after doping, was found to be 40%.     

Determination of Heparin in Plasma by HPLC Coupled with Resonance Light Scattering Detection

High performance liquid chromatography coupled with resonance light scattering detection was developed for separation and determination of heparin in plasma. A good chromatographic separation was achieved using an aminex HPX-87H column (300 mm × 7.8 mm, 9 μm) and a mobile phase of 5.0 mmol L⁻¹ H₂SO₄ at the flow rate of 0.5 mL min⁻¹. The enhanced resonance light scattering signals were derived from a large aggregate formation between heparin and cetyltrimethylammonium bromide used as the molecular recognition probe. The parameters of the post-column reaction (pH, concentration and flow rate of the reagent, length of the reaction coil, and temperature) were optimized. The limit of detection for heparin in plasma was 0.2 mg L⁻¹. The method has been applied to the determination of heparin in dialysis patient plasmas.

     

A Facile Synthesis of 6-Substituted Benzimidazo[1,2-c]-Quinazolines Under Microwave Irradiation

Microwave irradiation promoted the high-yield cyclocondensation of ortho esters (1a-f) with 2-(2-aminophenyl)benzimidazole (2), as the catalyst was no longer needed.     

Adsorptive BSA Coating Method for CE to Separate Basic Proteins

A novel and simple coating method was developed by coating bovine serum albumin (BSA) onto the inner surface of a fused-silica capillary, to avoid the adsorption of analytes during CE. The advantage presented here was that the coating process is more simple, fast, stable, and reproducible. The coated capillary avoided the adsorption of analytes onto the inner surface of a fused-silica capillary and might be a promising candidate for separation of complex biological samples with further development. Meanwhile, the efficiencies of the coated capillary were evaluated by EOF, chromatographic peak shape, and theoretical plate number (N m^?1) of RNase A. The optimal coating conditions were obtained from the results. The pH value of coating buffer PB was 4.2, the standing time was 12 h at 4 °C, and the coating concentration of BSA was 1.5 mg mL^?1. The stability of the coating on the inner wall of the capillary and the reproducibility of the coated capillaries were good. The theoretical plate number values of RNase A were over 1.3 × 10⁵ (N m^?1) in the coated capillary. After successive electrophoresis for 48 h using the coated capillary, the RSD values of EOF and the theoretical plate number were 4.14 % and 9.14 %, respectively. In addition, the RSD values of EOF and the theoretical plate number (N m^?1) in the coated capillaries were 13.19 % and 8.96 %, respectively. Finally, the coated capillary was successfully applied to separate the mixture of four basic proteins (RNase A, lysozyme, trypsin and myoglobin).     

Nucleophilic Reactivity of Ethers Against Terminal Epoxides in the Presence of BF3: A Mechanistic Study

In the presence of BF₃, a series of symmetrical and unsymmetrical ethers reacted with epichlorohydrin and 2‐[(benzyloxy)methyl]oxirane, two terminal epoxides, to afford 1‐alkoxy‐3‐chloropropan‐2‐ol and 1‐alkoxy‐3‐(benzyloxy)propan‐2‐ol. The cleavage of unsymmetrical ethers occurred via an S_N2 or S_N1 mechanism. Secondary epoxides did not give similar ring‐opening products.     

A Novel Synthesis of DL-proto-, and DL-vibo-Quercitol via 1, 4-Cyclohexadiene

Photooxygenation of 1, 4-cyclohexadiene 3 followed by reduction with LiAlH₄ or thiourea gave (25/1)-cyclohex-3-ene-triol 7a. trans-Hydroxylation of triol 7a with three different methods afforded both of proto-quercitol la and vibo-quercitol 2a.     

Reactions of Electron-Rich Olefins with Proton-Active Compounds

Abstract: From the reaction of electron-rich olefins, bis(1,3-dimethylbenzimidazolidine-2-ylidene), I, or bis(3-methylbenzothiazolidine-2-ylidene), II with proton active compounds, such as dimethyl phosphite, diethyl phosphite, acetonitrile and benzaldehyde were obtained 2-substituted benzimidazole or benzothiazole derivatives. The compounds synthesized were identified by ¹H, ¹³ C, ³¹P-NMR, mass, FT-IR spectroscopic techniques and micro analysis.     

A Convenient Synthesis of Alkyl and Aryl Substituted Bis-1,3,4-oxadiazoles

Substituted bis-1,3,4-oxadiazoles 3a-1 have been synthesized from the cyclization of N,N'-diaroyl or N,N'-dialkanoyl diacyl hydrazides, in presence of phosphorus oxychloride. A11 new compounds have been identified by ¹H-NMR ¹³C-NMR and elemental analysis.