Implication of Nucleinic Acids on Spectral Properties of Solves of Complexes of Pd(ii) and Pt(ii) With Aromatic Ligands

The interaction between nucleic acids (calf thymus DNA and plasmid pCY B3, yeast RNA) and ethylenediamine complexes of Pd(II) and Pt(II) containing aromatic heterocyclic ligands (2,2`-bipyridyl, 1,10-phenanthroline, 2-phenylpyridine, 2-(2`-ethyl)pyridine, 2-phenylpyridine, 2-(2`-ethyl)pyridine) was studied by electron absorption spectroscopy and gel electrophoresis, containing aromatic heterocyclic ligands (2,2`-bipyridyl, 1,10-phenanthroline, 2-phenylpyridine, 2-(2`-thienyl)pyridine, 7,8-benzoquinoline, methyl-2-phenyl-4-quinoline carboxylate, coumarin-6 and Nile red. The applicability of electron absorption spectroscopy to establish the intercalation of organometallic complexes in DNA was demonstrated. Of the investigated complexes, only complexes of Pd(II) with Nile red and coumarin-6 were found to be capable of intensive interaction with RNA. The effective unraveling of the secondary stranding of plasmid DNA detected by gel electrophoresis suggests that these same complexes intercalate into DNA more actively than others.