Synthesis, Crystal Structure, Fluorescence and Thermostability of Ni(II), Zn(II), Cd(II) Complexes with Schiff Base 2-Acetylpyridine-D-tryptophan

Three novel transition metal coordination polymers, [Ni(C18H16N3O2)(2)center dot 2CH(3)OH] (n) (1), [Zn(C18H16N3O2)(2)center dot 4CH(3)OH] (n) (2) and [Cd(C18H16N3O2)(2)center dot 2CH(3)OH] (n) (3) (C18H16N3O2=2-acetylpyridine-d-tryptophan) were synthesized and characterized by elemental analysis, IR, UV, H-1 NMR and X-ray diffraction single crystal analysis. The analyses of the structures indicate that all three materials crystallize in the tetragonal crystal system, space group P4(1)2(1)2. They have similar structures; i.e., the Schiff base coordinates in its deprotonated form and behaves as a hexadentate (4N+2O) coordinated ligand to form a distorted octahedron geometry. On the other hand, as a result of the alternate arrangement of chains through N-H center dot center dot center dot O intermolecular hydrogen bonds interactions, 2-D layers are formed for the three complexes. Furthermore, the luminescent properties and thermal stabilities of the three complexes were investigated.