The novel U(VI) and Np(VI) mixed-ligand complexes based on quinaldic acid zwitterion. (15th September 2022)

• Record Type: Journal Article
• Authors: Andreev, Grigory; Budantseva, Nina; Fedoseev, Aleksander
• Is Part Of: Polyhedron. Volume 224(2022)
• Publication Date: 2022-09-15
• Subjects: Uranium -- Neptunium -- Quinaldic acid -- Crystal structure -- Spectroscopy -- Complex formation; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2022.116003
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: Interaction of U(VI) and Np(VI) with quinaldic acid in the presence of various inorganic (nitrate, chloride, bromide, perrhenate, selenate, sulfate) and organic (dipicolinic acid) counter-ions allowed obtaining a series of complexes where quinaldic acid presents in the zwitterionic form. Determination of stability constants has shown that the complexation with quinaldic acid in solution occurs via coordination of the carboxylic group. Abstract: Interaction of U(VI) and Np(VI) with quinaldic acid in the presence of various inorganic (nitrate, chloride, bromide, perrhenate, selenate, sulfate) or organic (dipicolinic acid) counter-ions allowed obtaining a series of complexes where quinaldic acid presents in the zwitterionic form. In all compounds, except one complex, quinaldic acid acts as a monodentate ligand and coordinates metal centers via one of the carboxylic oxygen atoms. In all these cases, isolated molecular complexes are formed. In contrast, uranyl sulfate exhibits 2D layered structure where both sulfate-ions and molecules of quinaldic acid function as linkers. Determination of stability constants for 1:1 complexes has shown that the complexation of U(VI) and Np(VI) with quinaldic acid in solution likely occurs via coordination of the carboxylic group. Prevalence of the zwitterionic form and the coordination via carboxylic group both in solution and solid-state is unexpected taking into account similarity in structures of quinaldic and picolinic acids.