Prototropic tautomerism of (E)-N-((4-((2-hydroxy-5-methoxybenzylidene) amino)phenyl)sulfonyl)acetamide and its coordination abilities towards Ru, Rh, and Ir trivalent metal ions. (1st August 2022)

• Record Type: Journal Article
• Authors: Dąbrowska, Aleksandra M.; Mech-Warda, Paulina; Wera, Michał; Domżalska, Marta; Makowski, Mariusz; Chylewska, Agnieszka
• Is Part Of: Polyhedron. Volume 222(2022)
• Publication Date: 2022-08-01
• Subjects: Prototropic tautomerism -- Schiff base -- N-salicylideneaniline derivatives -- HOMO-LUMO orbitals -- Enol-imine keto-enamine equilibria -- Stability constants of Ir(III) -- Rh(III) and Ru(III) complexes; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2022.115909
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: This paper presents the synthesis, X-ray crystallographic measurements, spectral ATR and UV–Vis analysis and DFT calculations adopted for the new Schiff base type sulfonamide ligand to prove its existence in the mixture-form of enol/imine-keto/enamine tautomers stabilized by intramolecular hydrogen bonds. Additionally, the stabilities of the trivalent: iridium, rhodium and ruthenium ions complexes with ScB-SAM have also been investigated by spectrophotometric titration methods in water. The data showed that the examined coordination compounds were stable in solution based on the values of their stability constants found. Abstract: The Schiff base ( E )- N -((4-((2-hydroxy-5-methoxybenzylidene)amino)phenyl)sulfonyl) acetamide (ScB-SAM) has been synthesized bytheir condensation at room temperature in ethanol. X-ray crystallographic analysis revealed that the keto-enol tautomerism of its solid state exists as a complex equilibria system that is stabilized intramolecular hydrogen bond. The enol, keto and mixed enol-zwitterionic forms were observed in the crystal structure. The crystallographic results were supported by ATR, and UV–Vis. Physical properties were determined in different polar and nonpolar solvents and solid state. All above experimental results were then compared with DFT calculations. Additionally, the stabilities of the trivalent: iridium, rhodium and ruthenium ions complexes with ScB-SAM have also been investigated by spectrophotometric titration methods in water. The data showed that the examined coordination compounds were stable in solution based on the values of their stability constants found.