The spectral manifestations of the interaction between metal ions Co, Ni, Fe, Mg, Ag, Pt and DNA in the optical energy range (ultraviolet and visible range) were investigated and analyzed. The spectra of optical absorption, fluorescence, phosphorescence, phosphorescence excitation of the DNA macromolecule, DNA-metal solutions and drugs based on them were studied.It is shown that the disturbing effect of cobalt and nickel ions (as well as iron and magnesium ions studied in previous works) on the spin-orbit interaction in π electronic systems of DNA bases is insignificant, which is manifested in the absence of noticeable effects of "heavy atom" on DNA spectral properties. The experiments on photodegradation of these systems were performed. Based on obtained results, it is concluded that Co and Ni ions (studied in this work) and Fe and Mg (studied in previous works) binds to phosphorus groups on the periphery of the DNA macromolecule. At the same time, DNA with associated ions of these metals, play the role of traps for migrating triplet excitations in the DNA macromolecule, which is shown by the quenching of DNA phosphorescence with presence of Co and Ni ions. The length of triplet excitation obtained in the work is approximately 50 A (18-20 pairs of DNA bases), which coincides with the estimate of this value obtained in previous works.Unlike Co, Ni, Fe, Mg ions, the silver ions significantly (hundreds of times) increase the intensity of DNA phosphorescence and reveal an adenine-like structure in it, which is explained by the ability of penetration these ions into the space between the DNA bases. Such penetration leads to a significant perturbation of the spin-orbit interaction of the π electrons of the DNA bases and to the influence of the "heavy atom" effect.The applied part of the work is related to the study of the effect of cisplatin (a platinum-based compound that is a first-generation anticancer drug) on the spectral properties of DNA; spectral properties and photodegradation effects of the existing drug “Polyplatylene” (a complex of DNA with cisplatin - anticancer drug, which is second-generation drug). Based on the results of research, a scheme of electron excitation transmission in this drug is proposed, and conclusions were made on the influence of the presence of metals to the photostability of DNA and their toxic effect on DNA.
