A novel sensitized chemiluminescence: Infrared emissions from thiazine dyes sensitized by singlet oxygen |
| |
Authors: | Dale E. Brabham Michael Kasha |
| |
Affiliation: | Institute of Molecular Biophysics and Department of Chemistry, Florida State University, Tallahassee, Florida 32306, USA |
| |
Abstract: | An unusual infrared chemiluminescence emission (8130Å) of methylene blue, and other thiazine dyes, sensitized by singlet molecular oxygen is reported. This chemiluminescence does not correspond to the ordinary fluorescence of the dye and cannot be explained by previously proposed mechanisms for singlet oxygen sensitized emissions of dyes. From energetic considerations singlet molecular oxygen in its 1Σg+ state is postulated as the sensitizing agent for the thiazine dye chemiluminescences. Schemes in which 1Σg+ oxygen transfers electronic excitation energy (a) to the lowest triplet state of the dye, (b) to a combined multiplicity state of the lowest triplet state of the dye, and triplet molecular oxygen, or (c) to a charge-transfer state between the dye and oxygen, are compared. The chemiluminescence of methylene blue in aqueous solution may be used as a luminescent probe for 1Σg+ oxygen. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|