Experimental investigation on the effect of mesogenic ratio in hydrogen-bonded liquid crystal complexes

Hydrogen-bonded liquid crystal complex (HBLC) is synthesized from mesogenic 4-hexyloxy benzoic acid (6OBA) and aliphatic non-mesogenic citric acid (CA). The presence of intermolecular hydrogen bond in the HBLC complex is confirmed by FTIR spectrum. Phase transition temperature and enthalpy values are identified using different techniques. Induced highly ordered smectic G phase has been noticed in the present HBLC complex. Thermal span width and thermal stability factor of the individual mesogenic phase are discussed. The complexes are synthesized in different mole ratios, and their corresponding influence on the phase transitions is also discussed.     

Copper-catalyzed one-pot process to construct triazole-linked urea derivatives

A new one-pot synthetic methodology has been developed to construct the triazole-linked urea derivatives. In the same step, triazole forms from azide and alkyne via click reaction and urea forms from addition reaction of amines and isocyanates. The notable features of this work include wide substrate scope, atom economy, environmental friendliness, and easily accessible starting materials. The preliminary biological screening of synthesized compounds show promising cytotoxic activity in basal cell carcinoma (BCC) cell lines.     

Reductive cleavage of methyl orange under formation of a redox-active hydroquinone/polyaniline nanocomposite on an electrode modified with MWCNTs,and its application to flow injection analysis of ascorbic acid at low potential and neutral pH value

Microchimica Acta - The authors report on the electrochemical degradation of the dye Methyl Orange (MO) on a glassy carbon electrode (GCE) modified with multiwalled carbon nanotubes. Continuous...     

Separation of bulk Y from 89Y(n,p) produced 89Sr by extraction chromatography using TBP coated XAD-4 resin

⁸⁹Sr was produced using the ⁸⁹Y(n, p) ⁸⁹Sr reaction by irradiating yttria target in the fast breeder test reactor (FBTR). An analytical scale procedure was standardized for the removal of the bulk target yttrium by solvent extraction using the tri-n-butyl phosphate (TBP). The final purification of ⁸⁹Sr source was carried out by ion exchange chromatography. However, extraction chromatography is preferred to solvent extraction due to its low waste generation and ease of operation. This paper reports the separation of Sr from bulk Y and other radioactive impurities produced during irradiation by extraction chromatography using TBP coated XAD-4 resin. Initially the separation procedure was standardized using ⁸⁵Sr and ⁸⁸Y tracers. The ⁸⁹Sr in the dissolver solution of the irradiated yttria target was separated under the same standardized conditions. The study established the separation of Sr from Y in the dissolver solution of the irradiated target yttria by the TBP coated XAD-4 column. However the evaluation of the column after every use for about three separation studies exhibited the reduction in its breakthrough capacity for yttrium.     

Highly regioselective C4-hydrazinylation of 2,4-dichloroquinolines: expedient synthesis of aminoquinoline substituted pyrrolidin-2,5-diones via hydrazinylquinolines

A new class of hydrazinylquinoline regio-isomers has been synthesized through S_NAr reaction of 2,4-dichloroquinolines with hydrazine hydrate. The reaction stops at the mono-substitution product with high regioselectivity at the C₄ rather than C₂ position of dichloroquinolines. The hydrazinylquinolines were subsequently converted into aminoquinoline substituted pyrrolidin-2,5-diones in the presence of Eaton’s reagent.     

Twisted Hubbard model for Sr2IrO4: magnetism and possible high temperature superconductivity

Sr(2)IrO(4) has been suggested as a Mott insulator from a single J(eff)=1/2 band, similar to the cuprates. However, this picture is complicated by the measured large magnetic anisotropy and ferromagnetism. Based on a careful mapping to the J(eff)=1/2 (pseudospin-1/2) space, we propose that the low energy electronic structure of Sr(2)IrO(4) can indeed be described by a SU(2) invariant pseudospin-1/2 Hubbard model very similar to that of the cuprates, but with a twisted coupling to an external magnetic field (a g tensor with a staggered antisymmetric component). This perspective naturally explains the magnetic properties of Sr(2)IrO(4). We also derive several simple facts based on this mapping and the known results about the Hubbard model and the cuprates, which may be tested in future experiments on Sr(2)IrO(4). In particular, we propose that (electron-)doping Sr(2)IrO(4) can potentially realize high-temperature superconductivity.     

Integrated Nd-doped borosilicate glass microsphere laser

A neodymium-doped BK7 glass microsphere laser integrated with a planar ion-exchanged waveguide pumped at 0.8 μm has been demonstrated. The pump radiation was launched by evanescent coupling from the waveguide, and the signal radiation was coupled out through the same waveguide, offering the potential for robustly assembled fully integrated active optical circuits. The dependence of the lasing spectra on pump power and wavelength were studied in detail to clarify the whispering-gallery-mode behavior at the pump and lasing wavelengths.     

Residual Metal Impurity Aids Facile In Situ Electrochemical Surface Derivatization of Single‐Walled Carbon Nanotubes

Residual metal impurities were exploited as reactants in the functionalization of the surface of single‐walled carbon nanotubes (SWCNT) with nickel hexacyanoferrate (NiHCF) by simple electrochemical cycling in ferricyanide solutions. This facile in situ electrochemical modification process provides intimate contact between NiHCF and SWCNTs that improves the stability of the redox property and reactivity of NiHCF. The characteristic redox behavior of NiHCF on SWCNT surfaces can be used as an electrochemical probe to access qualitative and quantitative information on unknown electroactive metal impurities in SWCNTs. Significantly, the NiHCF‐modified SWCNTs exhibit pseudocapacitive behavior, and the calculated specific capacitances are 710 and 36 F g^?1 for NiHCF‐SWCNTs and SWCNTs respectively. Furthermore, NiHCF‐SWCNTs were transformed into Ni(OH)₂/SWCNTs and used for enzymeless glucose oxidation.     

A sequential RCM/fragmentation protocol towards chiral, stereodefined medium ring sesquiterpenoids. A carvone route to E- and Z-germacrenes

A short, flexible and enantioselective approach towards 10-membered germacratrienones, from the commercially available monoterpene chiron (−)-carvone, involving RCM and Grob-type fragmentation as the pivotal steps is delineated.