Isomeric complexes of ruthenium(II) with neutral heterocyclic schiff base ligands. High resolution proton resonance spectra of trans-cis isomeric pairs of RuX2L2 (L = 2-arylpyridinecarboxaldimine, X = Cl, Br) and comparison of their physical properties

The reaction of 2-arylpyridinecarboxaldimine [RH₄C₆NC(H)Py, L (1)] with hydrated RuX₃ (X = Cl, Br) in boiling C₂H₅OH affords dark crystals of RuX₂L₂. Two geometrical isomers of the compound have been isolated and characterized by analytical and spectroscopic data. The trans isomer of RuCl₂L₂ shows a single sharp band for ν(Ru---Cl), whereas two bands are observed for the corresponding cis isomer. The highresolution ¹H NMR spectra of the isolated complexes are reported and completely assigned. All the complexes have multiple t₂→π^*(L) transitions in the visible region. Each of the complexes display a quasi-reversible oxidative response due to an Ru^III/Ru^II couple in the range 0.25–0.40 V vs S.C.E. at a platinum working electrode. The formal potentials of this couple obey the Hammett relationship. The ligand-based irreversible oxidations are also briefly noted.     

Mining maximal frequent rectangles

Advances in Data Analysis and Classification - Interval data, a special case of symbolic data, are becoming more frequent in different fields of applications due to the uncertainty in the...     

Effect of nonextensivity on the characteristics of supersolitons in a two-temperature electron plasma

Ion-acoustic supersolitons are investigated in an unmagnetized two-temperature electron plasma comprising cold fluid ions, hot nonextensive electrons, and cool Maxwellian electrons by using the Sagdeev pseudopotential technique. Existence domain of positive polarity supersolitons in terms of Mach number is computed, which is found to exist for Mach numbers beyond the existence of positive double layers. The domain of existence of supersolitons diminishes with the decrease of the nonextensive parameter (q ). The amplitude and width of the supersolitons are dependent on the cool-to-hot electron temperature ratio (τ ), cool electron density (f ), and nonextensive parameter (q ). The increase of cool electron density increases the amplitude of the supersolitons. For fixed values of f , q _, and Mach numbers, the decrease of τ exhibits more distinct wiggles in the electric fields of supersolitons. The present work may be helpful for further study of supersolitons in the auroral plasma.     

Aptamer-Mediated Reversible Transactivation of Gene Expression by Light

The investigation and manipulation of cellular processes with subcellular resolution requires non-invasive tools with spatiotemporal precision and reversibility. Building on the interaction of the photoreceptor PAL with an RNA aptamer, we describe a variation of the CRISPR/dCAS9 system for light-controlled activation of gene expression. This platform significantly reduces the coding space required for genetic manipulation and provides a strong on-switch with almost no residual activity in the dark. It adds to the current set of modular building blocks for synthetic biological circuit design and is broadly applicable.