2,6-N,N'-diacetyldiaminopyridine (daapH), 2,6-N,N,-dibenzoyldiaminopyridine (dbapH) ligands and some of their solid transition metal complexes were purely prepared and recrystallized. The Nujol mull electronic absorption spectra have been undertaken for these materials before and after each γ-radiation doses of up to 109rd. Results obtained indicated that the electronic absorption spectral bands of material investigated suffer shifts, changes in intensity, broadening, creation of new bands and/or completely disappearance of others as a result of radiation damage. A sequence of the relative resistance of materials investigated towards gamma radiation damage was put forward.