Ruthenium-Komplexe mit Diazadienen. X. Cycloheptatrien als Dienyl-yl-ligand am Ruthenium

Article abstract of DOI:10.1016/0022-328X(89)87034-2

The bridge splitting reaction of <(c-C7H8)RuCl2>2 by piperidine (R''NH2) is different from the reaction of its oligomeric counterparts chloro-olefin-ruthenium complexes which give the corresponding hydrido complexes in that it gives the very reactive piperidido complex <(R''2N)Ru(c-C7H8)(R''2NH)2Cl> (2).Displacement of R''2NH from 2 with diazadienes (DAD = RN=CR'-CR'=NR) affords the new complexes <(R''2N)Ru(c-C7H8)(DAD)Cl> (6).A detailed NMR analysis reveals an unexpected conformation and bonding type of the cycloheptatriene: Five carbon atoms of the olefinic system form a ?-bonding dienyl system, while the sixth sp² center forms a localized bond to the metal.Complexes with not-too-bulky DAD ligands exhibit the presence of a second isomer (7), probably a rotational isomer with the olefinic ligand in the same conformation.