Triplet—triplet absorption of thioxanthone and triplet energy transfer to some organic azides

✍ Scribed by Hiroshi Morita; Shigeyasu Mori; Yoshio Sakaguchi; Hisaharu Hayashi

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 483 KB
• Volume: 59
• Category: Article
• ISSN: 1010-6030
• DOI: 10.1016/1010-6030(91)87065-4

✦ Synopsis

The energy transfer processes from thioxanthone (TX) and 2,4-diisopentylthioxanthone (DITX) to organic azides, such as ethyl-p-azidobenzoate (EAZB) and vinylbenzyl azide (VBAZ), were studied by measuring the transient absorption spectra and triplet decay rates of TX and DITX using an Nd:YAG laser flash photolysis technique. The energy transfer rates from both TX and DITX to the azides are close to the diffusion-controlled rate (lo9 M-' s-l). In ethanol, the rate of energy transfer from TX to the azides is approximately twice as fast as from DITX to the azides. The rate of energy transfer to VBAZ from both TX and DITX is 4-5 times faster than to EAZB. Energy transfer rates to EAZB in ethanol were compared with the values previously obtained from the measurement of the volume of nitrogen evolved under steady state conditions. The values previously obtained are approximately 50 times smaller than the present results, and can be attributed to the autocatalytic chain decomposition reaction of the azido group.