Mutagenicity of a series of hexacoordinate rhodium(III) compounds

19 rhodium(III) compounds have been tested for genetic damaging capabilities using an Escherichia coli differential repair assay and for mutagenicity in the strains of Salmonella typhimurium. 10 of these were active in both assays. Presence of the plasmid pKM101 was required for mutagenicity in Salmonella. Both the composition of the ligands and the three-dimensional structures of the coordination complexes profoundly affect genetic activity. In general, the structure—activity relationships appear to favor complexes with (1) a +1 charge, (2) 2 relatively labile leaving groups with 4 more strongly bonded amine ligands, and (3) a relatively slow rate of exchange of the ligands which is characteristic of substitutionally inert coordination complexes.