The reaction of 5, 5, 5-trifluoro-4-trifluoromethyl-pent-3-en-2-one with aminothiocarbonyls yielded aminothiourea precursors which readily cyclised to the corresponding thiazole derivatives, 5-(bis-trifluoromethyl) methyl)-2-aminothiazoles. The inhibitory potency of photosystem II activity of these thiazoles was evaluated using fluorescence measurement techniques. Two of the compounds showed a good activity in comparison with the ...