Half-sandwich bis(propiolamidinate) rare-earth metal complexes: synthesis, structure and dissociation of the cyclopentadienyl ligand via competition with an amidinate.

A comparative study on the stabilizing ability between C5Me4(SiMe3) (Cp' for short) and amidinate in rare-earth metal complexes is investigated. Cp' is found to dissociate from half-sandwich bis(propiolamidinate) lanthanides via competition with a propiolamidinate, which clearly shows that the coordinative ability of chelate amidinate is stronger than that of η(5)-Cp' under the present conditions.