Methods for the use of monocyclic arene radical anions, such as those of benzene, toluene, and mesitylene, in organometallic synthesis will be developed. These are extraordinarily potent reductants, which are capable of converting all known d- and f-block transition metal ions to zero or lower valent arene complexes. The recent availability in this laboratory of a variety of zerovalent group 4 carbonyls provides an opportunity to explore the chemistry of these elements in previously unknown oxidation states. The objectives will be to explore the chemical, electrochemical, and structural properties of these compounds as well as analogous group 5 carbonyls and to determine whether these new materials will be useful reagents in inorganic, organometallic, or organic synthesis. Possible extension of this research to the group 3 elements Sc, Y, and Lu, for which no carbonyls are presently known, will be an important component of the research. %%% In this project in the Inorganic, Bioinorganic, and Organo- metallic Program of the Chemistry Division, Dr. John E. Ellis of the University of Minnesota will continue to develop methods for the preparation of early transition metals in highly reduced oxidation states. The chemical, electrochemical, and structural properties of these compounds will be explored. These highly reduced metal ions may prove to be useful reagents in inorganic, organometallic, and organic synthesis.