Wydział Chemii

Nataliia S. Kariaka

Julia A. Rusanova

Sergii S. Smola

Sergey V. Kolotilov

Katerina O. Znovjyak

Marek Weselski

Tatiana Yu. Sliva

Vladimir M. Amirkhanov

2016

Polyhedron

106

44-50

10.1016/j.poly.2015.12.052

Naukowa

Angielski

Artykuł

The first representatives of pentanuclear carbacylamidophosphate complexes of composition Ln₅L₆(μ-L)₄(μ₃-OH)₄(μ₄-OH) (Ln^III=Eu (1), Gd (2), Tb (3), L⁻=dimethylbenzoylamidophosphate ion [C₆H₅C(O)-N-P(O)(OCH₃)₂]⁻) were obtained. The single crystal X-ray analysis revealed that polynuclear core of1contains five europium ions, connected by the μ₃- and μ₄-hydroxo groups and carbacylamidophosphate ligands. Compounds1-3were found to be isostructural. Temperature dependencies of magnetic susceptibility (χ_M) of the compounds1and2could be explained by spin-orbit coupling of Eu^IIIions or antiferromagnetic exchange interactions of four Gd^IIIions located in the base of Gd₅pyramid, respectively. In the case of 3, the value ofχ_Mincreases with temperature decreasing from 300K to 50K, and then falls down during temperature decrease till 2K. Such behavior can be explained by comparable contribution of spin-orbit coupling and exchange interactions. No signs of single-molecule magnet behavior for3were found at 2K. Phosphorescence, emission and excitation spectra at 298K and 77K for the complexes were measured, as well as luminescence decay times were determined. The compounds1and3showed intense luminescence with decay time at 298K equal to 0.66 and 1.44ms respectively. Intrinsic quantum yield for1determined from its emission spectrum was found to be 25%.

lanthanides, carbacylamidophosphates, Polynuclear complexes, luminescence, magnetic properties

http://dx.doi.org/10.1016/j.poly.2015.12.052

http://www.elsevier.com