The structure of dichlorobis(phenylamine)(bicyclo[2.2.1]hepta-2,5-diene)ruthenium: A π-bonded norbornadiene complex of ruthenium(II)

The structure of dichlorobis(aniline)(norbornadiene)ruthenium (aniline = phenylamine, norbornadiene = bicyclo[2.2.1]hepta-2,5-diene), RuCl₂ (C₇H₈)(C₆H₅NH₂)₂, has been determined from three-dimensional X-ray data collected by counter techniques and refined by a least-squares procedure to a conventional agreement index of 0.025. The complex crystallizes in space group C¹²_2vCmc2₁ of the orthorhombic system in a cell of dimensions a 17.162(4), b 12.589(3), c 8.522(2) Å, V 1841.3 ų with Z 4. Observed and calculated densities are 1.61(1) and 1.62 g/cm³. The coordination geometry about the ruthenium atom is distorted octahedral with the norbornadiene moiety bound through the two double bonds. The complex possesses crystallographically imposed C₃(m) symmetry with the trans-chloro ligands, the ruthenium atom, and the three sp³ carbon atoms of the diolefin constrained to the mirror plane. The coordination sphere is completed by cis-aniline groups. Bond distances of interest are: RuCt (where Ct is the center of the olefinic bond), 2.066(4); RuN, 2.213(3); RuCl, 2.415(2) and 2.407(1) Å. The CC distance of the olefinic bond is 1.386(6) Å, compared with 1.35 Å in the free ligand. The remaining distances in the bicyclic ligand are very close to the expected value for CC single bonds, 1.54 Å. The CtRuCt angle is 70.0° and the ClRuCl angle is 156.5(5)°.