Synthesis, Structural Features and Fluorescent Properties of Terbium Acylpyrazolone Complexes

Abstract Three 8‐coordinated terbium acylpyrazolone complexes [Tb(DMBPMP) 3 (H 2 O) 2 ] (Tb1), [Tb(DMBMCPMP) 3 (H 2 O) 2 ] (Tb2), and [Tb(DMBPTMP) 3 (H 2 O) 2 ] (Tb3) with a distorted bicapped trigonal prismatic structure were synthesized (where, 3,5‐dimethylbenzoyl 1‐(phenyl = DMBPMP/ m ‐chlorophenyl = DMBMCPMP/ p ‐tolyl = DMBPTMP) 3‐methyl 5‐pyrazolone). The structures of the complexes were comprehensively analyzed using mass ESI, FTIR, UV–vis, powder XRD, and TG‐DTA methods. Single‐crystal analysis of Tb3·H 2 O confirmed an eight‐coordinate structure (TbO8) with a distorted bicapped trigonal prismatic geometry. In the on‐state emission spectrum, the 5 D 4 → 7 F 5 transition exhibits hypersensitivity in the green region of the visible spectrum (∼540–560 nm). The differences between electric dipole (ED) and magnetic dipole (MD) transitions indicate a small degree of asymmetry. The examination of solid‐state emission spectra included the assessment of intensity, G/B ratio, green color purity, and the antenna effect energy diagram.