A Theoretical Treatment of the Absorption and Emission Properties of Cu(II) Porphyrin
Abstract
We examine the electronic spectrum of Cu(II) Porphyrin using the Intermediate Neglect of Differential Overlap (INDO) model that has been specifically parametrized for spectroscopy at the configuration interaction level of theory. The isolated molecule is predicted to have a trip-doublet absorption, corresponding to porphyrin triplets, at about 9,000/cm and 13,900/cm.The Q band is calculated at 15,900/cm, in good accord with experimental values. We predict a normal emission in this case, as is observed. We find that chelating in the fifth position with a strong ligand such as pyridine leads to a state in energy below the Q band that is mostly d(z squared)>d(x squared-y squared) but with appreciable a2u(Pi)>d(x squared-y squared) character. We postulate that it is the presence of this state that quenches the emission when Cu(II) porphyrins are complexed with strong fifth or fifth and sixth position ligands. jg
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 18, 1995
- Accession Number
- ADA293669
Entities
People
- Krassimir Stavrev
- Michael C. Zerner
Organizations
- University of Florida