A new route to the preparation of rhodium(III) diimine complexes which bind DNA by intercalation was developed by condensation of coordinated ammine ligands with o-quinones. Starting from cis-[Rh(L<^>L)(2)(NH3)(2)](3+) (L<^>L : 2,2'-bipyridine or 1,10-phenanthroline) and the appropriate quinones the ligands 9,10-phenanthrenequinone diimine (phi) and 5,6-chrysenequinone diimine (chrysi) were introduced in high yields. The reactions are completed within hours at ambient temperature in MeCN/water mixtures, 0.1 M in NaOH. Experiments with enantiomerically pure Delta-[Rh(phen)(2)(NH3)(2)](3+) and 9,10-phenanthrenequinone showed that the configuration at the metal center is retained during the course of the reaction. Condensation of rhodium(III) tetraammine starting material with 9,10-phenanthrenequinone allows the selective introduction of one or two ph ligands, depending on the reaction conditions. The ability to incorporate specifically.only one phi ligand makes this a promising approach for the synthesis of tris(heteroleptic) coordination compounds, and one example of such a complex, [Rh(phen)(phi)-(chrysi)](3+), is provided.