Add time:07/27/2019         Source:sciencedirect.com

The benzophenone- and acetophenone-photosensitized E—Z isomerization of BENZYLIDENE CAMPHOR (cas 15087-24-8) (BC) and p-trimethylammoniobenzylidene camphor methylsulphate was studied quantitatively. Initial sensitized quantum yields and concentrations of both isomers in the photostationary state were measured in CCl4 for the systems (BC + benzophenone) and (BC + acetophenone). Simultaneously, the rate constants of the quenching process of the phosphorescent triplet state of the two sensitizers were determined in CCl4. A diffusion-controlled energy transfer between acetophenone and BC accounts for the results, the energy transfer between benzophenone and BC being somewhat slower. In the sensitized isomerization of the trimethyl-ammonio derivative in CHCl3, phosphorescence quenching experiments and the determination of the photostationary states show that the quaternized derivative is as efficient as BC in quenching the triplet state of ketones. A well-known skin photosensitizer 8-methoxypsoralen (8-MOP) is observed to be an efficient sensitizer for the isomerization of the quaternized derivative of BC. The latter compound quenches the photocycloaddition of 8-MOP on N-methylmaleimide. It is concluded that BC and the trimethylammonio derivative show deactivating properties in addition to the usual filter effect.

We also recommend Trading Suppliers and Manufacturers of BENZYLIDENE CAMPHOR (cas 15087-24-8). Pls Click Website Link as below: cas 15087-24-8 suppliers