Luminescent properties of zinc complexes of 4-formylpyrazolone based azomethine ligands: Excitation-dependent emission in solution

A series of Zn(II) complexes based on 4-formylpyrazolone Schiff base derivatives have been synthesized and characterized by single crystal X–ray diffraction, ¹H NMR, FT–IR, and EA and photoluminescence studies. Single-crystal X-ray diffraction analysis indicates that complexes exhibit discreet molecular structure and zinc cation adopt distorted tetrahedral geometry. At room temperature, complexes in the solid-state exhibit high photoluminescence activities in blue range underlining its potential as promising photoactive material. Detailed studies of photo-luminescent properties of solutions of the complexes in various solvents indicate excitation-dependent emission, which allows to tune the emission color from blue to orange via the variation of the excitation light and the used solvents.