Ultrafast vibrational dynamics of a photoexcited metalloporphyrin

Document Type

Article

Publication Title

The Journal of Chemical Physics

Abstract

The ultrafast photodynamics of four-coordinate nickel (II) porphyrins in noncoordinating solvents has been studied using femtosecond time resolved optical spectroscopy. Unambiguous evidence has been found for the formation of a metastable metal (d,d) excited state in less than 350 fs following excitation of the macrocycle. However, the transient absorption spectrum of this ligand-field electronic excited state continues to evolve and reaches the steady-state form only after about 20 ps. This spectral behavior and the attendant complex kinetics can be modeled phenomenologically in terms of a broad distribution of the (d,d) excited states evolving to a narrower distribution. The dynamics are associated with vibrational relaxation. Intramolecular and intermolecular contributions to this process are considered. © 1989 American Institute of Physics.

First Page

3525

Last Page

3531

DOI

10.1063/1.456883

Publication Date

1-1-1989

Share

COinS