Construction of two Zn(II) complexes based on the oxime-containing Schiff base ligand with NO and N2O donor sets

Two zinc(II) complexes with NO- and N2O-set oxime-containing Schiff base ligand of 2-hydroxyimino-N′-[1-(2-pyridyl)ethylidene]propanohydrazone (Hpop), namely [Zn3(pop)2-(CH3OH)2Cl4] (1) and [Zn(pop)Cl]4·(H2O)2 (2), have been successfully synthesized from the reaction of Hpop with ZnCl2 in CH3OH under different temperatures and fully characterized by X-ray single-crystal diffraction, EA and IR as well as TG. At the low temperature, the linear M3L2-type trinuclear Zn(II) compound 1 was obtained, however, the grid-like Zn4L4-type tetranuclear Zn(II) compound 2 was given at the high temperature from the same reactants. Interestingly, compound 1 may be irreversibly transformed into 2 via ring-closed coordination reaction under the high temperature, accompanied by the corresponding changes in fluorescent property.