Preparation and characterization of uranyl complexes with phosphonate ligands

• Published in: Journal of thermal analysis and calorimetry 2010-04, Vol.100 (1), p.253-260
• Main Authors: Hnatejko, Z., Lis, S., Stryła, Z.
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Chemical properties; Chemistry; Chemistry and Materials Science; Coordination compounds; Decomposition; Emission; Exact sciences and technology; Infrared radiation; Inorganic Chemistry; Inorganic chemistry and origins of life; Ligands; Luminescence; Measurement Science and Instrumentation; Phosphates; Phosphonates; Physical Chemistry; Polymer Sciences; Preparations and properties; Spectroscopy; Thermal stability
• ISSN: 1388-6150; 1588-2926; 1572-8943
• DOI: 10.1007/s10973-009-0195-0

The preparation, spectroscopic characterization and thermal stability of neutral complexes of uranyl ion, UO 2 2+ , with phosphonate ligands, such as diphenylphosphonic acid (DPhP), diphenyl phosphate (DPhPO) and phenylphosphonic acid (PhP) are described. The complexes were prepared by a reaction of hydrated uranyl nitrate with appropriate ligands in methanolic solution. The ligands studied and their uranyl complexes were characterized using thermogravimetric and elemental analyses, ESI-MS, IR and UV–Vis absorption and luminescence spectroscopy as well as luminescence lifetime measurements. Compositions of the products obtained dependent on the ligands used: DPhP and DPhPO form UO 2 L 2 type of complexes, whereas PhP forms UO 2 L complex. Based on TG and DTG curves a thermal stability of the complexes was determined. The complexes UO 2 PhP·2H 2 O and UO 2 (DPhPO) 2 undergo one-step decomposition, while UO 2 PhP · 2H 2 O is decomposed in a two-step process. The thermal stability of anhydrous uranyl complexes increases in the series: DPhPO