No abstract

Natural Polysaccharides are polymers composed of monosaccharide units bound together by glycosidic linkages. In their native form, these polymers may not be able to provide all the desired properties for a particular application. Thus, the functionalization of its reactive hydroxyl groups would change their surface properties. In this work, we evaluated the derivatization of OH groups of maltodextrin polysaccharide with urea. By a one-pot selective procedure carried out at room temperature for 3 h, urea united at maltodextrin through covalent bonding was obtained. The results showed that after functionalization with urea, the pH and solubility in polar solvents of the new material increased. Derivatization of maltodextrin with urea confers stability, and terminal amide groups on the surface of this material represent a versatile reactive functional group for conjugation with other molecules for potential applications in the development of new materials.

Metal ions are of great significance to the environment and biological system. Particularly, trivalent -iron, aluminium and chromium -and divalent -copper, mercury, cadmium, and zinccations are some of the more important. Recently we have report two new ligands derived from bisvanillin, useful for discriminate between Fe 3+ , Al 3+ and Cr 3+ .Considering these results, we present a theoretical study based on the Functional Density Theory related with structures of bis-vanillin derivatives contained a hydrazoline or isoniazide moiety into the complexation types of both ligands with M 3+ cations. Moreover, we realize a predictive theoretical study to explore the ligands' complexation with M 2+ cations. The optimized structures of the ligands and their cation complexes are presented and discussed.

A novel byphenyl hydrazone ligand developed as a chemosensor for the detection of Cu2+ was studied using a theoretical analysis based on the density functional theory (DFT) and time-dependent DFT (TD-DFT). The geometries of the ligand (L) and the Cu2+-ligand complex were optimized at the CAM-B3LYP/631+G(d,p) level of theory in dimethyl sulfoxide, using the conductor-like polarizable continuum model. The adsorption spectra of these molecular systems were analyzed and compared with the experimental data. Theoretical study of the structural, electronics and optical properties allowed us to understand the chemical changes that the ligand undergoes in the complexation process with the Cu+2 ion.