Spectral-luminescent characteristics of coordination compounds and metal polymers of Yb(III)

Abstract

New mono- and heteroligand (with phenanthroline or dipyridyl) metal complexes of ytterbium (III) with 2-methyl-5-biphenylpentene-1-3,5-dione were synthesized in this work. Homo- and copolymers of ytterbium complex with methyl methacrylate or styrene were obtained by the method of radical polymerization. Coordination compounds were investigated by IR spectroscopy, diffuse reflectance spectroscopy, thermal and luminescence analyses. It was determined that the -diketone molecules are bidentate-cyclically coordinated to the central atom, and the coordination sphere of the monoligand complex is supplemented by two water molecules, which in the case of heteroligand complexes (HLC) are replaced by phenanthroline or dipyridyl molecules. An increase in thermal stability of heteroligand complexes and metallopolymers was observed compared to the metallocomplex. The spectral properties of the synthesized compounds were studied and it was established that the structure of the coordination node of the elementary link of polymer macromolecules does not change during the polymerization process. It was shown that all the studied samples exhibited 4f-luminescence in the near-infrared region of the spectrum, while the lowest relative luminescence intensity was characteristic of ytterbium (III) homopolymer and copolymers, and the highest values were shown by heteroligand complexes with phenanthroline, which allows us to propose them as precursors of luminescent materials.