A continuation of the investigation of robust metal complexes formed by the basic building blocks of the more highly elaborated biological molecules is proposed. The goal is to control the site of attachment of the metal ion, and to learn how the properties of the ligands--for example amino acids, nucleobases and simple derivatives of each class--are affected by coordination, but recognizing that the modification of properties is reciprocal. Of particular interest are the effects of the metal ion in changing the reactivity to nucleophilic substitution in the ligand, and to the ease of oxidation or reduction. The interactions of Ru(II) and Ru(III) are especially featured, the former because it is unique among octahedral species of oxidation state 2+ in forming robust complexes and because of its capacity to modify properties by backbonding, and the latter, because ligand-to-metal charge transfer can modify properties. Special benefits derive from the fact that each of the adjacent oxidation states, which are easily interconverted by a redox process, forms roburst complexes. The research extends to the congeners Os(II) and Os(III), and to Rh(III). Comparisons of the results for the different metal centers make it possible to relate the differences to fundamental properties of the metal ions such as their electronic structure. Work will also be done with a bimetal unit, Rh24+, which because of its particular structure is expected to show some unique interactions.
