Conserved Hydrogen Bonded Tartrate Frameworks: Inclusion of Amines and Implications for Second Harmonic Generation

A series of anilinium cations with various functional groups as substituents has been chosen to form salts with l-tartaric acid and d-dibenzoyl tartaric acid. The salts show second harmonic generation activities comparable to urea. The tartrate frameworks provide conformationally rigid hydrogen bonded frameworks for the incorporation of these cations. The SHG activity of these salts appear to depend upon the type of framework provided by the tartrate anions, which in turn decides the orientation of the cations.     

Electrogeneration of Hg(+) in the presence of tryptophan

In the presence of l-tryptophan, a one-electron oxidation of mercury takes place at the dropping mercury electrode at 0.265 V vs. SCE in 0.1M potassium nitrate. The electrogeneration of the monomeric Hg(+) ion has been established by a.c. polarography, cyclic voltammetry and ultraviolet spectroscopy. A paramagnetic Hg-trp compound has been electrochemically synthesized and characterized.     

Crystallization kinetics of Cu3Ti2 forming from Cu60Ti40 glass

Amorphous to crystalline transformation in Cu₆₀Ti₄₀ alloy has been studied under conditions of constant heating rate experiments, using XRD and DSC. In the high temperature XRD experiment, the transformation has been monitored continuously as the integrated X-ray intensity corresponding to a chosen reflection from one of the two crystalline products forming at close by temperatures. Differentiation of the curve thus obtained gives the transformation rate curve which passes through a maximum. From the peak shift with heating rate, the activation energy for the formation of Cu₃Ti₂ crystalline phase has been obtained. The results have been compared with those obtained by DSC.     

Wave propagation in a micropolar fluid contained in a visco-elastic membrane

The aim of the paper is to investigate the propagation of a pulse in a micropolar fluid contained in a visco-elastic membrane. It was undertaken with a view to study how closely we can approximate the flow of blood in arteries by the above model. We find that for large Reynolds number, the effect of micropolarity is hardly perceptible, whereas for small Reynolds numbers it is of considerable importance.     

Chemoprofiling and Solamargine Estimation from a Few Solanum Species Used as ‘Brihati’ and Its Market Samples Using a Validated High-Performance Thin-Layer Chromatography Method

JPC – Journal of Planar Chromatography – Modern TLC - An ingredient of ‘Dasamoola’ and ‘Laghupanchamoola’ group of drugs, the source of ‘Brihati’ has...     

Stabilization of merocyanine by protonation, charge, and external electric fields and effects on the isomerization of spiropyran: a computational study

Protonation, charging, and field effects on the thermal isomerization of a nitrospiropyran (SP) modified by a thiolated etheroxide chain into merocyanine (MC) are computationally studied at the DFT level. The ring opening leads to cis-MC conformers that then isomerize to the more stable trans forms. While the closed neutral spiropyran is more stable than the conjugated open forms, the merocyanine conformers are significantly stabilized by protonation, electron attachment, and ionization. For protonation on the pyran oxygen atom and electron attachment, the MC conformers are more stable than SP, and unlike for the neutral species, the ring opening is spontaneous at room temperature. Moreover, for the pyran oxygen-protonated form, the ring opening to the cis-merocyanine becomes barrierless. On the other hand, barriers comparable to the neutral remain along the thermal pathway to the cis-merocyanine conformer for ionization or electron attachment, and the barrier for isomerization is significantly higher for the N-protonated SP form. External field effects on the neutral reaction path show that ring opening to the cis-merocyanine is favored when the field reduces the electron density on the pyran part, as also induced by the local field due to O protonation.     

Codense and completely codense ideals

Summary We characterize codense and completely codense ideals.