Copper(II) complexes with spherical morphology generated in one step by amphiphilic ligands: in situ view of the self-assembling, characterization, catalytic activity

Publication date: 5 November 2019Source: Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580Author(s): Georgiana-Oana Turcan-Trofin, Mirela-Fernanda Zaltariov, Mihail Iacob, Vasile Tiron, Florin Branza, Carmen Racles, Maria CazacuAbstractCyclotri- and tetrasiloxanes having a methyl group and a carboxylic acid coupled through thioether bridge at each silicon atom were used to coordinate copper(II). The amphiphilic character conferred by the co-existence of the two moieties with opposite behaviour on the silicon atom gives the molecule the ability to form aggregates in solution. When copper salt is added, the metal is quickly coordinated by carboxyl groups within these aggregates, as in situ taken microscopy images and video reveal, forming blue spheres. This morphology was confirmed by scanning and transmission electron microscopy, while the coordinating structures and their compositions were estimated by IR spectroscopy and UV–Vis diffuse reflectance spectroscopy, wide angle X-ray diffraction and energy-dispersive X-ray analysis. The wetting tests and moisture sorption analysis indicate hydrophobic materials, while thermal analysis shows a thermal stability of at least up to 180 °C. The compounds catalyze the decomposition of H2O2 in alkaline medium, the values found for the rate constant being between 0.8 and 3.8 × 10−3s-1.Graphical abstract

Source: Colloids and Surfaces A: Physicochemical and Engineering Aspects - August 28, 2019 Category: Chemistry Source Type: research