Key words: supercritical carbon dioxide, photosensitized oxidation, anthracene, porphyrins
A photosensitized oxidation of anthracene and cholesterol in supercritical carbon dioxide (SC-CO2) in the presence of fluorinated tetraphenylporphyrins (FTPP) containing hydrocarbon substituents with different chain lengths (characterized by the number of carbon atoms n) in para-position of the phenyl rings as sensitizers is carried out for the first time. The rate of such process in SC-CO2 is much higher than in conventional organic solvents, in chloroform in particular. The value of the apparent rate constant of anthracene photooxidation keff increases with increasing n due to a higher probability of the formation of the complex between the substrate and a more spatially extended FTPP molecule at increasing n number. Such complex can be an intermediate in the formation of anthraquinone — the only product in the photooxidation of anthracene in SC-CO2.