Study on the Coordination and Photophysical Property of Transition Metal Complexes Bearing Fused Heterocyclic N-donor Ligand

Abstract

Multidentate N-donor ligands have played many fundamental roles in chemical science. For example, often they are critical factors in transition metal-mediated reactions to achieve high efficiency, selectivity and robustness by providing the well-defined primary and secondary coordination sphere around the transition metals. From a viewpoint of biomimetic system, the well-defined coordination sphere given by a certain N-donor ligand is an essential requirement not only to maintain intrinsic functions of metalloproteins but also to reproduce the short-lived intermediates in synthetic systems. In particular, di(2pyridyl)ketone has shown its versatility in developing N-donor supporting ligands for biomimetic transition-metal complexes. In this context, we have synthesized a fused heterocyclic multidentate N-donor ligand, 1,3-di(pyridine-2-yl)imidazo[1,5-α]pyridine (dipyip), using the di(2-pyridyl)ketone as a starting material. We also have prepared transition meal complexes by using the same ligand to investigate their coordination mode and PL properties. In this study, structural characterization, and spectroscopic properties will be discussed.