Neutral Terbium(III) Tris(complex) with 4,4,5,5,6,6,6-Heptafluoro-1-(1-methyl-1H-pyrazol-4-yl)hexane-1,3-dione: Synthesis, Structure, and Spectral Luminescence Properties

Abstract

The reaction of 1,3-diketone containing 1-methyl-1H-pyrazol-4-yl and perfluoropropyl fragments with TbCl₃·6H₂O in the presence of NaOH in ethanol is studied. The molecular and crystal structures of the complex are studied by single-crystal X-ray diffraction (XRD). Compound [Tb(L)₃(EtOH)₂] crystallizes in the triclinic crystal system with the space group \(P\bar {1}\). The geometry of the coordination polyhedron {LnO₈} corresponds to a square antiprism. Intermolecular interactions N…H–O, C–H…O, and C–H…F leading to the formation of supramolecular chains are observed in crystals of the complex. The UV-irradiated complex exhibits green luminescence caused by transitions ⁵D₄ → ⁷F_j (j = 2–6) characteristic of the Tb³⁺ ion. The main photophysical luminescence parameters are determined, and the scheme of energy transfer in the complex is proposed. The synthesized compound can be of interest as an independent luminophore or as the initial substance for the synthesis of heteroligand complexes by the substitution of ethanol molecules in the internal coordination sphere.