Spectral and Luminescent Properties of N,N'-Bis(salicylidene)-1,4-Butylenediamine, N,N'-Bis(5-bromosalicylidene)-1,4-Butylenediamine, and Their Complexes with Zinc(II)

The spectral and luminescent properties of N2O2-type aromatic azomethines, N,N'-bis(salicylidene)-1,4-butylenediamine, N,N'-bis(5-bromosalicylidene)-1,4-butylenediamine, and their complexes with Zn(II), have been studied. All compounds at 293 K fluoresce in solutions and in a polycrystalline state. An increase in the fluorescence intensity of the azomethines in alcohol solutions occurs upon their conversion to the quinoid form. The main photoluminescent parameters of solutions of the compounds in DMF and DMSO have been determined. Depending on the presence of bromoaryl substituents in the structure of the ligands and the solvent properties, the zinc complexes fluoresce with quantum yields up to 50%.