Highly regioselective ring opening of quinolinic[2,3]anhydrides under mild conditions

We report a study of the influence of Lewis acids upon the regioselectivity of ring opening of quinolinic[2,3]anhydrides to provide 2-(isopropoxycarbonyl)-nicotinic acids. In the presence of stoichiometric amounts of indium trifluoromethanesulfonate or lanthanum trifluoromethanesulfonate, the desired 2-position ester was generated with greater than 95:5 regioselectivity. This methodology was also applied to 6-methyl-[2,3]-quinoline to provide similar results.     

Quantum Monty Hall Problem under Decoherence

We study the effect of decoherence on quantum Monty Hall problem under the influence of amplitude damping, depolarizing, and dephasing channels. It is shown that under the effect of decoherence, there is a Nash equilibrium of the game in case of depolarizing channel for Alice＇s quantum strategy. Whereas in case of dephasing noise, the game is not influenced by the quantum channel. For amplitude damping channel, Bob＇s payoffs are found symmetrical about a decoherence of 50% and the maximum occurs at this value of decoherence for his classical strategy. However, it is worth-mentioning that in case of depolarizing channel, Bob＇s classical strategy remains always dominant against any choice of Alice＇s strategy.     

Thermo physical properties of acetone–zinc bromide for using in a low temperature driven absorption refrigeration machine

Thermal physical properties (vapor pressure, density, viscosity, specific heat capacity, specific electrical resistance and specific enthalpy of mixing) of the solution acetone–zinc bromide, which will be used as a working solution in an absorption refrigeration machine, are measured and analyzed. The experimental data were correlated with high accuracy. The required state diagrams (log p, T and h, T) for this solution as well as the log P, h-diagram for the pure acetone are calculated, represented, correlated and discussed. The results indicate that the solution acetone-zinc bromide might be suitable as a working solution to operate an absorption refrigeration machine at low temperature.     

Triflate Induced C-N Coupling of Sugars with Heterocyclic Bases: Synthesis of a New Class of Compounds

A new class of pharmacologically interesting compounds has been synthesized through a novel S_N2 displacement of trifluoromethanesulfonyloxy group in protected sugar (1) with a variety of secondary heterocyclic cases (2–6). The reaction pathway also provides a possible route to alklodial N-glycosides.     

One-pot synthesis and luminescent spectra of 3-allyl substituted quinazoline-2,4-dione derivatives as allyl capping agents

3-Nitro-N-(phenylsulphonyloxy)phthalimide (IIIa) and N-(phenylsulphonyloxy)phthalimide (IIIb) were synthesised as key intermediates in good yield. Their structures were confirmed by ¹H NMR and FTIR spectral data. The reaction of the key intermediates with allylamine produced 3-allyl-5-nitroquinazoline-2,4-(1H,3H)-dione (IVa) and 3-allylquinazoline-2,4-(1H,3H)-dione (IVb), respectively. Luminescence emission and excitation spectra of IVa and IVb are also presented.     

Morphological Effect on Fluorescence Behavior of Silver Nanoparticles

Effect of Silver nanoparticles (AgNPs) morphology on their fluorescence behavior is reported. AgNPs sol stabilized by Ethylene Diamine Tetra Acetic-Acid (EDTA) was prepared by chemical reduction method. Morphology of the AgNPs was tuned through changing the Ag⁺ ion concentration and P^H of reaction mixture. Additional peaks observed in surface Plasmon resonance spectra suggest the an-isotropic nature of AgNPs. Actual morphology was judged by Transmission Electron Microscopy. Emission spectra recorded using Spectrofluoremeter suggest the fluorescent nature of AgNPs, which also influenced by morphology of AgNPs and attributed to the variation in surface structure of an-isotropic AgNPs.

Electrodeposition of 3D Ordered Macroporous Germanium from Ionic Liquids: A Feasible Method to Make Photonic Crystals with a High Dielectric Constant

A promising method for the production of germanium photonic crystals consists of electrodeposition of Ge from GeCl₄‐containing ionic liquids inside templates of polystyrene colloidal crystals and subsequent removal of the template. This room‐temperature method gives rise to the fabrication of a three‐dimensional highly ordered macroporous germanium nanostructure (see picture; scale: 2 μm) as a prototype of a photonic crystal.

     

Cationic nitrile‐functionalized Ag(I)‐ and Hg(II)‐N‐heterocyclic carbene complexes of CCC,CNC, and NCN pincer‐type carbene ligands: Synthesis,crystal structures,and characterization

Three nitrile‐functionalized (benz)imid‐ zaolium derivatives with CCC, CNC, and NCN coordination pockets have been synthesized and isolated as the bromide salts and are converted into their hexafluorophosphate counterparts ( 5–7 ) by ligand metathesis. N‐heterocyclic carbene Ag(I)‐ and Hg(II)‐complexes ( 8–10 and 11–13 ) are readily formed in good to excellent yields from ligand precursors 5–7 and Ag₂O and Hg(OAc)₂, respectively. All reported compounds have been characterized by various spectral and analytical techniques, such as FTIR, ¹H, and ¹³C NMR spectroscopy and X‐ray diffraction studies. Solid‐state structures of carbene precursors 5 , 7 , and an Ag(I)–carbene complex 10 have been determined crystallographically. Single crystal X‐ray crystallography of complex 10 reveals the chelation of carbene carbons to metal center in almost a linear manner. © 2012 Wiley Periodicals, Inc. Heteroatom Chem 23:486–497, 2012; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.21041     

Tate twists of Hodge structures arising from abelian varieties of type IV

We show that certain abelian varieties $A$ have the property that for every Hodge structure $V$ in the cohomology of $A$, every effective Tate twist of $V$ occurs in the cohomology of some abelian variety. We deduce the general Hodge conjecture for certain non-simple abelian varieties of type IV.