Investigation by ESR Spectroscopy of Biology Active Electron-Rich 1,10-Phenanthrocyanines of d-Elements (Soft Colloidal Glasses)

The 1,10-phenanthrocyanines of d-elements were investigated by ESR spectroscopy both in the solid (glassy) state and in solutions. These are coordination compounds of a new structural class of apocyanines: chromophore binuclear cation complexes [M²⁺L_n(µ-PC)]₂X_m (M²⁺ = Zn²⁺, Cd²⁺, Co²⁺, Pd²⁺and Pt²⁺; L = 1,10-phenanthroline, 2,9-Me₂-1,10-phenanthroline, pyridine; X = AcO⁻, Cl⁻) with electron-rich bridged 1,10-phenanthrocyanine ligands µ-PC. They are presented as soft colloidal glasses capable of acting as inhibitors of tumor cell proliferation, fungicides and DNA complexones. The study of them by ESR spectroscopy showed that one of the possible mechanisms for the formation of spin centers is thermally directed singlet–triplet S₀ → T_low.-transitions.