Substituent Effects on the Optical Properties of Free Base (Alpha,Beta, Gamma,Delta)-Tetraphenylporphyrin
Abstract
Optical limiting devices have gained importance as more laser threats have been developed. The purpose of this project was to study the optical properties of various substituted groups on TPP and use the information obtained to improve materials under investigation for potential use as optical limiting dyes. Compounds were obtained that had substituents added to the phenyl groups of free base tetraphenyl porphyrin. Absorption peak shifts, molar extinction coefficient, oscillator strength, fluorescence peak shifts, and fluorescence quantum yield were measured. Hammett sigma values were used to quantify the electron donating/withdrawing capacity of the substituents. All optical properties studied showed a change in value based on the electron donating/withdrawing strength of the added substituent. Both absorbance and fluorescence spectra showed a red shift with more electron donating substituents. Molar extinction coefficient, oscillator strength and fluorescence quantum yield all showed an increase with more electron donating substituents. These trends can be used to design better optical limiting materials in the future.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 28, 1998
- Accession Number
- ADA356244
Entities
People
- Kirsten M. Wohlwend
Organizations
- Wright State University