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The photochemical reactions of aryl-substituted digermanes were investigated by trapping experiments and a laser flash photolysis technique. The photolysis of phenylated digermanes resulted in germanium–germanium bond homolysis to give a pair of two germyl radicals. The germyl radicals abstracted a chlorine atom from carbon tetrachloride to give chlorogermanes. The pair of germyl radicals also underwent ipso-substitution, which was a precursor of the germylenes. The mechanism for the photochemistry of phenylated digermanes is discussed.

The recombination of pairs of para-substituted phenylthiyl radicals inside micellar supercages was studied by means of a nanosecond laser flash photolysis technique. Singlet and triplet pairs were formed by direct excitation and by triplet-sensitized photolysis of the corresponding disulfides, respectively. Magnetic field effects (MFEs) on the yield of escaped thiyl radicals were found for the triplet-sensitized photolysis of the p-amino compound. For the p-hydroxy-, p-methoxy-, and p-butoxy compounds, short-lived MFEs were observed but it is unlikely that they arise from the recombination of the thiyl radicals. No MFE was found on pairs of p-chloro-substituted and unsubstituted phenylthiyl radicals within experimental error

The photochemical introduction of trifluoromethyl group with CF3Br in aromatic and heteroaromatic rings was investigated for 9 compounds. Naphthalene, anthracene, anisole, N,N-dimethylaniline, ferrocene, benzo[b]thiophene, isoquinoline, and N-methylpyrrole gave trifluoromethylated products in 6.5–100% yields. In one step from uracil, a pharmacologically important 5-trifluoromethyluracil can be synthesized by this method in 11% yield. Based on the mechanistic study carried out for the naphthalene–CF3Br–CH3CN system, the reaction is found to proceed via the electron transfer from an excited singlet state of naphthalene to CF3Br.