Wydział Chemii

Yen Hoang Pham

Viktor A. Trush

Maria Korabik

Volodymyr M. Amirkhanov

Paula Gawryszewska

2021

Dyes and Pigments

186

108986/1-108986/11

10.1016/j.dyepig.2020.108986

Naukowa

Angielski

Artykuł

The increased interest in designing bifunctional magnetic-luminescent compounds stems from their promising application potential. Appropriately designed lanthanide coordination compounds were found suitable for this purpose. This work describes the structural, optical and magnetic properties of photostable lanthanide coordination compounds (Nd, Yb) with N-(diphenylphosphoryl)pyrazine-2-carboxamide (HL) acting as an antenna. Optical properties of the compounds were characterized by IR, high-resolution absorption and emission spectroscopies at 300, 77 and 5 K. The trinuclear coordination compounds (labeled as Na₂LnL₄), with a crystal structure stiffened by eight oxygen bridges with eight-coordinated lanthanide ion, as well as six- and seven-coordinated Na ions, were found to be excellent converters of UV radiation into the NIR. The ligand-to-metal energy transfer mechanisms in Na₂NdL₄ were discussed. Na₂YbL₄ reached the highest ( = 5.8%) overall emission quantum yield among the coordination compounds of Yb³⁺ with organic ligands in solid state. The static and dynamic magnetic properties of Na₂NdL₄ and Na₂YbL₄ were studied, revealing that the compounds exhibit behavior of field-induced Single Ion Magnets (SIMs) with the effective energy barrier value of 27.4 K (Na₂NdL₄) and 26.2 K (Na₂YbL₄). The anisotropic barrier was extracted from static magnetism and optical properties analysis, giving an insight into the magneto-optical correlation. We demonstrated that proper design of ligand structure and coordination compound architecture allows to obtain molecular magnets with optimized infrared emission.

Lanthanide, Phosphorylated carboxamides, Energy transfer, Single-ion magnet, Luminescence, Crystal structure

http://doi.org/10.1016/j.dyepig.2020.108986

http://www.elsevier.com