Synthesis and coordination behaviour of the new (8-quinolyl)cyclopentadienyl ligand

8-Bromoquinoline reacts with zincated cyclopentadienyl derivatives of Fe, Mn, and Re in the presence of bis(triphenylphosphine)palladium(0) to yield the corresponding 8-quinolylcyclopentadienyl metal complexes. Tricarbonyl[η5-(8-quinolyl)cyclopentadienyl]manganese(I) (5) and tricarbonyl[η5-(8-quinolyl)cyclopentadienyl]rhenium(I) (6) eliminate CO upon irradiation to form dicarbonyl[η5-(8-quinolyl)cyclopentadienyl]manganese(I) (7) and dicarbonyl[η5-(8-quinolyl)cyclopentadienyl]rhenium(I) (8), respectively. The intensely coloured complexes 7 and 8 show solvatochromism, which has been investigated in more detail. Coordination of the quinolyl moiety in 7 and 8 could be proved by spectroscopy and by crystal structure determination.