A new series of 2,5-bis(4-methylphenyl)-1,3,4-oxadiazole derivatives: their synthesis and fluorescence properties for anion sensors

A new series of 2,5-bis(4-methylphenyl)-1,3,4-oxadiazole derivatives containing various substituted groups on the ortho-position to oxadiazole ring was synthesized and their fluorescent sensor properties were investigated. The fluorescent sensor molecules showed UV absorption shift as well as fluorescence emission shift upon exposure to fluoride anion in DMF solution, which was considerably dependent on the substituent attached on the phenyl group. The new sensory compound, 1d can be used as a fluoride anion sensor in terms of naked-eye detection and fluorescent sensing with high selectivity.     

Synthesis of poly-substituted pyrroles starting from the Baylis-Hillman adducts

We synthesized poly-substituted pyrrole derivatives 4a-e, 7a-c and 10a-d from the reaction of phenacyl bromide and the aza-Baylis-Hillman adducts 1a-d or their rearranged derivatives 5a-e. The pyrroles were synthesized via the successive N-alkylation, Michael addition, elimination of p-toluenesulfinic acid and oxidative aromatization processes.     

Electric field isolator (EFI) for isolated and electrophoretic manipulation of charged biomolecules

This paper describes a novel technology-an electric field isolator (EFI)-that can be used for achieving isolated and electrophoretic manipulation of charged biomolecules inside a selected microscopic location. The EFI is a ground ring-shaped electrode (RE) surrounding a centre electrode (CE), which is comprised of a functional unit. When the CE is powered, the ground RE can inhibit the electric field from spreading to the neighbouring functional units. Therefore, the electrophoretic movement of the charged molecules in an electric field, which is based on the principle similar to that of electrophoresis, can be isolated inside a selected location. The ground RE causing this phenomenon is referred to as the EFI. In this paper, we clearly show the functionality of the EFI with mathematical and experimental studies.     

A Reduced Third Order Markov Model for Ethylene‐Norbornene Copolymerization Kinetics with Homogeneous Metallocene Catalysts

A reduced third order Markov model is presented to model the kinetics of ethylene‐norbornene copolymerization over rac‐Et(1‐indenyl)₂ZrCl₂/methylaluminoxane catalyst in solution. In our previous work, we developed a penultimate model (second order Markov model) to describe the copolymerization rate behavior and the copolymer composition. Although the penultimate model provides better predictions of the polymerization kinetics than a simple terminal model, it tends to give underestimated norbornene incorporation rates at high norbornene/ethylene mole ratios in the bulk liquid phase. In this work, we propose a modified third order Markov model to improve the model's capability of calculating norbornene incorporation rate and comonomer sequence distribution. The model parameters have been estimated using a parameter optimization technique. The model simulation results indicate that the rate constant for norbornene insertion into a growing chain depends upon the norbornene microblock length at the propagating center.

     

A color version of the Hinsberg test: 1 degrees -3 degrees amine indicator

The Hinsberg test to recognize the type of amine (1 degrees -3 degrees amines), which has been established for more than 100 years and well documented in textbooks, is not possible without conducting complicated organic reactions. We report for the first time unique chemosensors that are capable of showing selective color changes toward 1 degrees -3 degrees amines as a color version of the Hinsberg test. This simple and straightforward qualitative analysis, using the synthesized novel compounds herein, can be considered a new innovative tool for discriminating 1 degrees -3 degrees amines as an alternative to the historical Hinsberg test.     

Area-selective growth of amorphous carbon nanofibers via catalytic decomposition of polyimide thin film

A dense layer of amorphous carbon nanofibers was fabricated by pyrolyzing a thin film of polyimide using a monolayer of gold nanoparticles as a catalyst.     

A practical procedure for producing silver nanocoated fabric and its antibacterial evaluation for biomedical applications

A novel and universal procedure has been developed for producing nanosized stable silver particles on cotton fabrics in a simple and cost-effective manner with complete control of the silver loading level on the fabrics; the antibacterial effect of Ag-nanocoated fabrics on various bacteria was evaluated by growth inhibition; for biomedical applications, skin irritation tests on guinea pigs were performed and no side effects were observed.     

Practical solid-phase parallel synthesis of Delta(5)-2-oxopiperazines via N-acyliminium ion cyclization

A practical solid-phase strategy for the synthesis of Delta(5)-2-oxopiperazines via N-acyliminium ion cyclization has been developed. A key step in the library synthesis is tandem acidolytic cleavage with subsequent in situ iminium formation, followed by stable enamide transformation. This approach is exemplified by the preparation of a 192-member pilot library using bromoacetal resins without further purification.     

Calix[4]thiacrowns as ditopic hosts for homo- and heterobinuclear accommodation: first report of a chopsticks-type pi-coordination

[reaction: see text] Calix[4]thiacrowns with hetero-L(1) and a homodonor set (L(2)) were synthesized and characterized by X-ray analysis. From the reaction of L(2) with AgPF(6), disilver complex [Ag(2)(L(2))](PF(6))(2) (1) was isolated. By comparing 1,3-alternate conformations of L(2) and 1, we found a considerable decrease of dihedral angles of two opposite aromatic rings upon complexation. This finding can be explained in terms of the "chopsticks process", which illustrates how Ag(+)-arene pi-coordination occurs. Heterobinuclear complexation of L(1) in solution was also observed.