η5,η1-Coordinated cyclopentadienyl transition metal complexes featuring σ-metal–carbon ansa bridges

An overview of η5,η1-coordinated transition metal ansa complexes is given. These compounds bear one or more coordinated cyclopentadienyl moieties connected with a η1-bridging σ-bonded carbon chain featuring a length of at least two carbon atoms. Synthetic approaches, as well as characterisation and applications are described.