Abstract

The nickel(II) porphyrins have been well suited for an ideal system for investigating electronic decay, axial ligand photodissociation and photoassociation dynamics.¹Of great significance in governing photophysics of the four- and six-coordinate nickel(II) complexes is the presence of a low-lying metal excited $\left({\text{d}}_{{\text{z}}^2},{\text{d}}_{{\text{x}}^2-{\text{y}}^2}\right)$ state having ~250 ps lifetme below porphyrin ring (π,π^*) states.¹ The (d,d) excited state shows characteristic sharply featured absorption difference spectra, compared to the broader featured more diffuse spectra of the ring (π,π^*) and metal⇔ring charge transfer excited states. This favorable properties of the nickel(II) complexes provide a good opportunity for examining the deactivation dynamics in the porphyrin and its interaction with environment that may accompany a transition from an electronic excited state of the macrocycle to an electronic excited state of the metal.

© 1996 Optical Society of America