The influence of ortho-substitution within the ligand on the geometry of the tris(2,2′-bipyridine)ruthenium(II) and tris(1,10-phenanthroline)ruthenium(II) ions

The crystal structures of tris(2-methyl-1,10-phenanthroline)ruthenium(II) iodide, tris(6-methyl-2,2′-bipyridine)ruthenium(II) tetrafluoroborate and tris(6,6′-dimethyl-2,2′-bipyridine)ruthenium(II) tetrafluoroborate 0.75 hydrate are described. The average Ru-N distances in the complex cations are 2.063, 2.089, and 2.119 Å, severally. The substituents in the ligands exert a strong influence on the geometry of the coordination core, which deviates significantly from regular octahedral. The deviation is most marked for the dimethyl-substituted system where pronounced inter-ligand forces result in gross angular distortion of the relative orientations of the three ligand molecules.