Two di-nuclear Cd(II) and Mn(II) complexes with one new poly-dentate double Schiff base ligand derived from 1,10-phenanthroline: Syntheses, structures, and physical properties

A new poly-dentate double Schiff base ligand 1,10-phenanthroline-2,9-dicarboxaldehyde-di-2-hydroxybenzoylhydrazone (H2L) was synthesized and structurally characterized. Two CdII and MnII dimers of this ligand were also synthesized, and their crystal structures and photoelectronic spectra were characterized. In the two dimers, ligand L acts as a bridge in the interesting mono–poly-dentate bridging mode. The ligand and its CdII complex strongly emit at 525 nm and 570 nm, respectively, and thus can be utilized as potential fluorescent materials. Furthermore, magnetization measurements for its MnII dimer in the range 5–300 K indicate two magnetic orderings, at high temperature (T > 230 K) a ferromagnetic ordering is observed, and below this temperature, an antiferromagnetic behavior takes place.