Jörn‐Uwe Thurner

Photochemically induced reactions of 5-diazobarbituric acids in solution.

Quantum yields were detd. for the photolysis of diazobarbituric acids I (R = H, Me, 1-naphthyl, 2-naphthyl, R1 = H; R = R1 = Me, cyclohexyl, Ph). Photolysis of I (R = R1 = cyclohexyl) in EtOH in the presence of air gave the hydantoin II whereas in the absence of air 1,3-dicyclohexylbarbituric acid was obtained.

EPR-Untersuchungen an Radikalen und Triplettzuständen von Fluorenderivaten

The photolysis of 9-diazofluorene-derivatives yields various paramagnetic species. By EPR-spectroscopy at continuous and modulated optical excitation these species have been identified as radicals as well as triplets in ground- and excited states. In the simulation and interpretation of the spectra comparison with structure analogous compounds and products was helpfull. On the basis of the results the possible role of the paramagnetic intermediates in the reaction-scheme is discussed.