ESR Spectroscopy of Temperature Accessible Lowest Triplet States of Biology Active Electron-Rich 1,10- Phenanthrocyanines of d-Elements (Soft Colloidal Glasses)

Abstract

Temperature accessible lowest electronic triplet biradical states of new metal 1,10-phenanthrocyani-nes were investigated by ESR spectroscopy. These are coordination compounds of a new structural class of cyanines: nanosize chromophore binuclear cation complexes of d-elements [Mz+Ln(µ-PC)]2Xn (Mz+=Zn2+, Cd2+, Pd2+and Pt2+; L=1,10-phen, py, AcO-; X=AcO-, Cl-) with electron-rich 1,10-phenanthrocyanine ligands. They are presented as redox-sensitive polymorphic soft collo-idal glasses capable of acting as inhibitors of tumor cell proliferation, environmentally friendly fun-gicides and DNA complexones related with NADH. The study of them by ESR spectroscopy sho-wed that one of the possible detailed mechanisms of the formation of triplet states in the processes of thermo-directed singlet-triplet S0→Tlow.-transitions consists in thermally activation of rotation around the sesquialteral C—C bond dihydro-1,10-phenanthroline and 1,10-phenanthroline frag-ments in the bridged chromophore system of compounds.