P-C Bond Cleavage Induced Ni(II) Complexes Bearing Rare-Earth-Metal-Based Metalloligand and Reactivities toward Isonitrile, Nitrile, and Epoxide.

Protonolysis of β-diketiminato (nacnac) rare-earth metal bis-alkyl complexes LnacnacLnR2(THF) (Ln = Y and Lu) with 2 equiv of Ph2PNHPh or Ph2PCH2NHPh afforded the bis-amido complexes LnacnacY(Ph2PNPh)2 and LnacnacLn(Ph2PCH2NPh)2 (Ln = Y and Lu). Metalation of the latter complexes with 1 equiv of Ni(COD)2 led to the isolation of unusual heterobimetallic Ni(II)-Ln(III) complexes formed via P-C bond cleavage of one [Ph2PCH2NPh]- ligand. Notably, both the imine PhN═CH2 and phosphide Ph2P- fragments from the P-C bond cleavage were trapped in the Ni(II)-Ln(III) core with a relatively weak interaction between the two metal centers. The Ni(II)-Y(III) complex have exhibited versatile reactivity, such as coordination of isonitrile to the Ni(II) center, insertion of nitrile with the coordinated imine, and ring-opening of the epoxide by nucleophilic attack from the phosphide group.