The influence of ortho-substitution within the ligand on the geometry of the tris(2,20-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-2,20-bipyridine)ruthenium(II) tetrafluoroborate and tris(6,60-dimethyl-2,20-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 A ° , 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 dimethylsubstituted system where pronounced inter-ligand forces result in gross angular distortion of the relative orientations of the three ligand molecules. q 2004 Elsevier B.V. All rights reserved.