Remarkable Effect of Iridium Cyclometalation on the Nonlinear Absorption Properties of a Quadrupolar Imine Ligand

A new type of dinuclear iridium complex,
based on a quadrupolar
Schiff base ligand, is synthesized and its structure fully characterized.
Its linear and nonlinear spectroscopic properties are investigated,
evidencing a strong contribution of the metal-to-ligand transitions
not only to the linear absorption but also to the two- and three-photon
absorption properties.