Unusual Formation of Cyclometallated C,H-trans-Hydridoruthenium(II) Complexes and Their Isomerization into C,H-cis-Types

The aromatic C-H bonds of N-benzylideneaniline and 2-phenylpyridine are cleaved by [RuH2(CO)(PPh3)3] and triethoxyvinylsilane at 70-110 °C to give the corresponding cyclometallated hydridoruthenium(II) complexes. The X-ray structure analyses of these complexes reveal that the hydrido ligand is initially situated trans to aryl group of the cyclometallated moiety and these two ligands are moved mutually into cis-sites by heating.