Photochemical and photophysical properties of piroxicam and benoxaprofen in various solvents.
Laser flash spectroscopy was used to examine the title compounds. Piroxicam has a triplet transient with a maximum near 450 and a lifetime of 3-21 microseconds depending on the solvent. The relative quantum yield is highly solvent dependent being maximum in toluene and greater than or equal to 14 fold lower in hydrogen bonding solvents. There is another transient which is assigned as a proton transferred ground state transient. Some permanent photoproduct also appears to be produced. Benoxaprofen also has a triplet transient with a maximum near 420 nm with a lifetime of 65 microseconds to greater than or equal to 250 microseconds depending on the solvent. In this case, the relative quantum yield only slightly varies among polar and hydrogen bonding solvents. This is in marked contrast to published data on the fluorescence yield. Some permanent photoproduct appears to be produced.
Becker
R S
RS
Department of Chemistry, University of Houston, TX 77204-5641.
Chakravorti
S
S
Yoon
M
M
D000894:Anti-Inflammatory Agents, Non-Steroidal; D010777:Photochemistry; D055585:Physical Phenomena; D010825:Physics; D010894:Piroxicam; D011422:Propionates; D012997:Solvents; D013053:Spectrophotometry
D000894:Anti-Inflammatory Agents, Non-Steroidal; D011422:Propionates; D012997:Solvents; D010894:Piroxicam; C011677:benoxaprofen