Luminescence properties of complexes Ln(Phen)(C6F5COO)3 (Ln = Tb, Eu) and Ln(C6F5COO)3 · nH2O (Ln = Tb, n = 2; Ln = Eu, n = 1). Structures of the [Tb2(H2O)8(C6F5COO)6] complex and its isomer in the supramolecular compound [Tb2(H2O)8(C6F5COO)6] · 2C6F5COOH

Abstract

Complexes Ln(Phen)(C6F5COO)3 (Ln = Tb, Eu; Phen = 1,10-phenanthroline) (I, II) are synthesized. At 300 K these complexes and compounds Ln(C6F5COO)3 · nH2O (Ln = Tb, n = 2; Ln = Eu, n = 1) (III, VI) possess photoluminescence (bright in the case of I and II). In the spectrum of compound I the line at 545 nm (transition 5 D 4 → 7 F 5) is most intense, whereas in the spectrum of compound II the most intense is the line at 613 nm (transition 5 D 0 → 7 F 2). The replacement of Phen by water decreases the luminescence intensity. The compound [Tb2(H2O)8(C6F5COO)6] · 2C6F5COOH (IV) is synthesized. According to the X-ray diffraction data, in structure IV the molecules of the binuclear Tb(III) complex with the C6F5COOH molecules form a supramolecular ensemble due to hydrogen bonding. The C6F5COO− ligands perform the monodentate and bidentate bridging function, resulting in the opening of the eight-membered cycle Tb2C2O4. The TbO8 polyhedron is a distored tetragonal antiprism. The crystals of the binuclear complex [Tb2(H2O)8(C6F5COO)6] (V) are obtained in which the C6F5COO− ligands are monodentate and tridentate bridging cyclic, which results in the closure of two four-membered cycles TbO2C and one four-membered cycle Tb2O2. The TbO9 polyhedron is a distorted monocapped tetragonal antiprism.