Photostability of model extractants like hydrophobic esters (dioctyl, 2-ethythexyl or didodecyl) and amides (contg. 2-ethylhexyl, dihexyl or dibutyl group) of pyridine-3,5-dicarboxylic acid and their complexes with Cu(II) was detd. in toluene or (4:1 v/v) octane-toluene (alone or with water) as solvent, in air or Ar, on 0-600-min UV-VIS or UV irradiation. Up to 10 hrs., amides were more stable than and, in =10 hrs, as stable as, esters. Octane (full degradation took 6 hrs.), (HO)-O-2, air, full spectral range of light, and long alkyl chains accelerated, whereas aq. HCl and wavelengths =300 nm decelerated photodegradation; Cu(II) and Cl ions had minor effect. In esters, the O-C and aliphatic C-C bonds were ruptured and substituted with solvent-derived radicals; in amides, the N-C and aliphatic C-C bonds were ruptured only, the entire amide group was split off. In the amides contg. dialkyl groups, preliminary photodegradation improved slightly the extn properties.