Ferrocenyl-nucleobase conjugates include ferrocene and nucleobase subunits that are covalently connected by different bridges. The chemical stability of ferrocene allows its incorporation into biomolecules such as nucleobases. The combination of these two subunits brings both electrochemical and biochemical activities into one molecule. These properties have sparked great interest in the development, synthesis and study of ferrocenyl-nucleobase conjugates for their possible biochemical and pharmaceutical applications.Since many potential applications of ferrocenyl nucleobases involve the reversible one-electron oxidation of ferrocene groups, their characterization should include diamagnetic ferrocene as well as its paramagnetic derivative ferrocenium. In this project we will apply electron paramagnetic resonance (EPR) spectroscopy from room temperature to ~4 K and electrochemical, spectroscopic and computational chemistry methods to provide detailed characterization of various newly synthesized mono- and bis-ferrocenyl-nucleobases with carbonyl groups as a linker (ferrocenoyl-nucleobases conjugates). EPR will provide detailed analysis of ferroceniums over wide temperature ranges and complement optical and nuclear magnetic resonance (NMR) spectroscopy and cyclic voltammetry at higher temperatures. Experimental results will be compared with computational results for the purpose of deeper insight into the issue.We expect that this project will significantly deepen the insight into the structural and redox properties of ferrocenoyl-nucleobase conjugates, as well as into the magnetic properties of ferrocenium cations, which would ultimately help greatly in the design of the application of these compounds. Also, as part of this project, it is planned to improve the EPR spectroscopic technique in the study of organometallic complexes, which will be useful for similar research during and after the completion of the project.