A 3-V electrochemical capacitor study based on a magnesium polymer gel electrolyte by three different carbon materials

An organic medium with lithium and sodium salts is not so safe in some cases. Structural features of carbon electrodes play a vital role on the capacitor parameters. Based on that above said, we have studied three kinds of supercapacitors using a gel electrolyte from 0.5 M of magnesium imide salt–polyethylene oxide (PEO) in propylene carbonate (PC). The cell electrodes were carbide derived carbon (CDC), PICACTIF and YECA activated carbons. The gel component interactions were viewed by infrared spectroscopy. The cell reversibility and symmetric were analyzed using cyclic voltammetry (CV) technique. Linear sweep voltammetry (LSV) technique was taken to approximate the electrolyte stability. Electrochemical impedance spectroscopy (EIS) result reflects the resistance and capacitive behavior of the cells, i.e., The YECA carbon shows a good capacitive behavior over the CDC- and PICACTIF-based cells whereas the CDC cell has shown a low resistance. Galvanostatic charge-discharge study (CD) results have shown a stable and ideal 2.5-V capacitor behavior. The capacitors have also proven an obtainable good specific capacitance, real power, and real energy density of ~25 F g^?1, 0.7 kW kg^?1, and 25 W·h kg^?1, respectively. Moreover, the cells were tested for 3-V limit.     

Synthesis of some monocyclic‐N‐acetyl 4′‐aza‐D‐nucleosides

1,2,3,5‐Tetra‐O‐acetyl‐4‐deoxy‐4‐(acetamido)‐β‐D‐ribofuranose 5 was prepared from L‐lyxose, which on condensation with silylated nucleoside bases gave the corresponding protected 4′‐azanucleosides. The protecting groups were removed using methanolic ammonia to afford the N‐acetyl‐4′‐azanucleosides, wherein the sugar ring oxygen is replaced with a substituted nitrogen atom, in good yields. Further, the 1‐(4‐deoxy‐4‐acetamido‐β‐D‐ribofuranosyl)thymine 16 was transformed to the corresponding 2′‐deoxy, 2′,3′‐dideoxy derivatives. The stereochemical assignments of the synthesized nucleosides were established based on NMR and X‐ray studies.     

Characterization of melt grown phthalic anhydride single crystal

The bulk organic single crystal of phthalic anhydride (PA) was grown by vertical Bridgman technique. The structural perfection of the grown crystal was analysed by high resolution X‐ray diffraction (Multicrystal X‐ray diffractometry) studies. The thermal and mechanical properties have been studied. The second harmonic generation relative efficiency of Phthalic anhydride crystal is compared with KDP crystal. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Growth and characterization of 4‐Aminopyridinium‐4‐nitro phenolate single crystals

Organic optical material 4‐Aminopyridinium‐4‐nitro phenolate (4AP4NP) has been synthesized, and single crystals of size 20 x 14 x 6 mm³ have been grown from acetone solvent at room temperature by solvent evaporation technique. The grown crystals have been characterized by X‐ray diffraction to determine the cell parameters, and by FT‐IR technique to confirm the formation of the expected compound. The crystal belongs to monoclinic crystal system with space group P2₁/a.The structural perfection of the grown crystals has been analyzed by high‐resolution X‐ray diffraction (HRXRD) rocking curve measurements. The thermal stability of the compound has been determined by TG‐DTA curves. The transmittance of 4AP4NP has been used to determine the refractive index n; the extinction coefficient K and both the real ε_r and imaginary ε_i components of the dielectric constant as functions of photon energy. The optical band gap of 4AP4NP is 2.4 eV. The dielectric and mechanical behavior of the specimen was also studied. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Growth and characterization of sulphamic acid single crystals grown by Sanakaranarayanan‐Ramasamy (SR) method

By directional solidification, single crystal of Sulphamic acid (SA) was successfully grown from aqueous solution by Sankaranarayanan‐Ramasamy (SR) method. A vertically designed L‐bend was used to avoid the effect due to spurious nucleation. A vertical bottom‐seeded ampoule was used for the growth of single crystal. A seed crystal was mounted at the bottom of the ampoule. Sulphamic acid crystals of up to 40 mm in diameter and 60 mm in length have been grown with a growth up to 10 mm per day. The grown sulphamic acid single crystal was characterized using X‐ray powder diffraction analysis, Raman, FTIR, and optical transmission studies. The dielectric behaviour was measured in the frequency range of 1 kHz–10 MHz for the temperature ranges from 30 °C to 170 °C. The sulphamic acid single crystal was also grown by conventional method. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Ultrasound-Facilitated Direct meta-C−H Functionalization of Arenes: A Time-Economical Strategy under Ambient Temperature with Improved Yield and Selectivity

The horizon of ultrasound-assistance has been expanded to palladium-catalyzed distal C−H functionalization of arenes. Compared to thermal conditions, operationally simple ultrasound mediated distal C−H functionalization occurred with a shorter reaction time and enhanced reactivity of reactants to give superior yields with improved selectivity both in terms of meta:others and mono:di. A wide variety of meta-functionalizations such as olefination, alkylation, acetoxylation, allylation and cyanation were successfully carried out under ambient temperature.     

Enantiodivergent synthesis of both enantiomers of gypsy moth pheromone disparlure

Enantiodivergent synthesis of both (-)- and (+)-disparlure, a bioactive pheromone, possessing a cis-epoxide has been accomplished. The key step involves the cross metathesis of a chiral homoallylic alcohol derived from l-(+)-tartaric acid.