IRON AND RUTHENIUM COMPLEXES HAVING A ?-N, μ2-N', η2-C=N' BONDED 6-R1-py-2-C(R2)=NR LIGAND; X-RAY STRUCTURE OF CONTAINING TWO C-C LINKED PYRIDINE-2-CARBALDEHYDE-IMINE ...

Article abstract of DOI:10.1016/0022-328X(86)80154-1

The pyridine-2-carbaldehyde-imines R¹-py-2-C(R²)=NR (R-Pyca) react with Fe2(CO)9 to give Fe2(CO)6(R-Pyca) and Fe(CO)3(R-Pyca) and with Ru3(CO)12 to Ru2(CO)6(R-Pyca).Further reaction of Ru2(CO)6(R-Pyca) with R-Pyca gives Ru2(CO)5(R-APE)(R-APE = 1,2-bis(μ-alkylamido)-1,2-bis(2-pyridyl)ethane), in which R-APE consists of two C-C linked R-Pyca ligands.One representative Ru2(CO)5(R-APE) compound, viz. that with R = i-Pr, has been studied by X-ray diffraction.The compound Ru2(CO)5(i-Pr-APE) is monoclinic, space group P2/n with two molecules in a unit cell of dimensions a 14.499(5), b 9.051(3), c 9.772(4) Angstroem and β 103.54(4) deg; Z = 2, R = 0.057 for 1743 observed reflections.Although the crystals were not of sufficient quality to warrant detailed discussion of the structure, it is clear that the 10e donor APM ligand bridges the Ru2(CO)5 unit in which there is no Ru-Ru bond. 1H and 13C NMR data for the free ligands and their Fe and Ru complexes are discussed, with emphasis on ?-backbonding from the Group VIII metal to the imine C=N' bond.