First examples of carbacylamidophosphate pentanuclear hydroxo-complexes: Synthesis, structure, luminescence and magnetic properties. (26th February 2016)

• Record Type: Journal Article
• Authors: Kariaka, Nataliia S.; Rusanova, Julia A.; Smola, Sergii S.; Kolotilov, Sergey V.; Znovjyak, Kateryna O.; Weselski, Marek; Sliva, Tatiana Yu; Amirkhanov, Vladimir M.
• Is Part Of: Polyhedron. Volume 106(2016)
• Page Start: 44
• Page End: 50
• Publication Date: 2016-02-26
• Subjects: Lanthanides -- Carbacylamidophosphates -- Polynuclear complexes -- Luminescence -- Magnetic properties; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2015.12.052
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: The three novel pentanuclear Eu III, Gd III and Tb III carbacylamidophosphate based complexes were synthesized. The crystal structures of Eu5 L10 (OH)5 was solved. Temperature dependencies of magnetic susceptibility of the named compounds were investigated. Phosphorescence, emission and excitation spectra at 298 K and 77 K for the complexes were measured, as well as luminescence decay times were determined. Thermal stability of the europium complex was investigated. Abstract: The first representatives of pentanuclear carbacylamidophosphate complexes of composition Ln5 L6 (μ-L)4 (μ3 -OH)4 (μ4 -OH) (Ln III = Eu (1), Gd (2), Tb (3), L − = dimethylbenzoylamidophosphate ion [C6 H5 C(O)–N–P(O)(OCH3 )2 ] − ) were obtained. The single crystal X-ray analysis revealed that polynuclear core of1 contains five europium ions, connected by the μ3 - and μ4 -hydroxo groups and carbacylamidophosphate ligands. Compounds1 –3 were found to be isostructural. Temperature dependencies of magnetic susceptibility ( χ M ) of the compounds1 and2 could be explained by spin-orbit coupling of Eu III ions or antiferromagnetic exchange interactions of four Gd III ions located in the base of Gd5 pyramid, respectively. In the case of 3, the value of χ M increases with temperature decreasing from 300 K to 50 K, and then falls down during temperature decrease till 2 K. Such behavior can be explained by comparable contribution of spin-orbit coupling and exchange interactions. No signs of single-molecule magnet behavior for3 were found at 2 K. Phosphorescence, emission and excitation spectra at 298 K and 77 K for the complexes were measured, as well as luminescence decay times were determined. The compounds1 and3 showed intense luminescence with decay time at 298 K equal to 0.66 and 1.44 ms respectively. Intrinsic quantum yield for1 determined from its emission spectrum was found to be 25%.