cyclometalated Pt(II) complexes with azo- or imine-based ligands were synthesized and structurally characterized. These Pt(II) complexes had square-planar structures, with cyclometalation resulting in six-membered ring formation and highly distorted square-planar geometry. The Pt(II) complex with an azo-based ligand easily underwent cyclometalation, even at room temperature, while the Pt(II) complex with