Coordination chemistry of neutral quinolyl- and aminophenylcyclopentadiene derivatives

The cyclopentadiene and indene derivatives 1–4 being functionalised by a dimethylaniline and quinolyl group, respectively, were treated with metal carbonyl complexes. Whereas cyclopentadienes (C5R5H) normally loose one hydrogen atom prior or during metal complex formation, leading to negatively charged cyclopentadienide ligands, the compounds 1–4 are able to act as neutral ligands without hydrogen loss. Consequently transition metal complexes with coordination of the nitrogen donor and a CC double bond of the five membered ring have been obtained. In some cases a hydrogen atom is eliminated and the expected η5-(C5R5) complexes are formed. Reaction of Ru3(CO)12 with 2 leads to the binuclear η6-fulvene complex 8. The octahedral molybdenum complex 9 and the square planar rhodium(I) complexes 10 and 11 which were obtained from Mo(CO)6 and [Rh(CO)2Cl]2, respectively, are rare examples of η2-(C5R5H) coordination to metal atoms.