The Anomalous Metalloporphyrin and Chlorophyll a Activated Chemiluminescence of Dimethyldioxetanone. Chemically Initiated Electron-Exchange Luminescence.
Abstract
A wide range of fluorescent electron donors catalyze the chemiluminescence of dimethyldioxetanone (1) by the chemically initiated electron-exchange luminescence (CIEEL) pathway. In general, the magnitude of the catalytic rate constant, the efficacy of excited state generation correlate well with the one electron oxidation potential of the donor. Exceptions to this correlation are several zinc and magnesium porphyrins, including chlorophyll a, for which their chemiluminescent catalysis is much greater than predicted by their oxidation potentials. The critical role of the central metal atom in eliciting this unusual behavior was evaluated by determining the catalytic rate constants and the initial chemiluminescence intensity of several non-metallated as well as differently metallated porphyrins. These results suggest that formation of a ground state complex between 1 and certain metalloporphyrins is the cause of the unusual catalysis. Spectroscopic evidence of a ground state complex between zinc tetraphenyl porphyrin (ZnTPP) and tetramethyldioxetane, a model for 1, has been obtained. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 26, 1980
- Accession Number
- ADA081660
Entities
People
- Gary Schuster
- Steven P. Schmidt
Organizations
- University of Illinois Urbana–Champaign