Vanessa R. Landaeta

The solid‐state emmissive chalcone (2E)‐1‐(5‐chlorothiophen‐2‐yl)‐3‐[4‐(dimethylamino)phenyl]prop‐2‐en‐1‐one

Orange rectangular blocks suitable for X-ray diffraction analysis were obtained for the previously reported [Ahmad & Bano (2011). Int. J. ChemTech Res. 3, 1470-1478] title chalcone, C15H14ClNOS. This solid-emissive chalcone exhibits a planar structure and the bond parameters are compared with related compounds already described in the literature. The determination of the structure of this chalcone is quite relevant because it will play an important role in theoretical calculations to investigate potential two-photon absorption processes and could also be useful for studying the interaction of such compounds with a biological target.

Determination of stability constants of ternary copper(II) complexes formed with picolinic acid and several amino acids

ABSTRACT In this work, the formation of ternary complexes with their respective formation constants in the systems formed by copper (II), picolinic acid and the amino acids = histidine (His), aspartic acid (HGly), proline (HPro), α-alanine (HαAla), β-alanine (HβAla), serine (HSer), threonine (HThr), phenylalanine (HPhe) and methionine (HMet)) was detected. The analysis involves the use of the potentiometric data with the least-squares program LETAGROP in aqueous solution at 25°C in 1M KNO3 solution. The relative stability of the ternary complexes was compared with the binary ones considering the values of Δlog K and log χ. Subsequently using the formation constants, the species distribution diagrams were generated and are briefly discussed here. The Cu (II)–picolinic acid–glutamic acid, Cu (II)–picolinic acid–serine and Cu (II)–picolinic acid–histidine systems were characterised by UV–Vis molecular absorption spectroscopy and cyclic voltammetry, obtaining results that confirm the formation of ternary complexes with octahedral geometry.