New tris-amidinate actinide (Th, U) complexes containing a rare O-bound terminal phosphaethynolate (OCP - ) ligand were synthesized and fully characterized. The cyanate (OCN - ) and thiocyanate (SCN - ) analogs were prepared for comparison and feature a preferential N-coordination to the actinide metals. The Th(amid)3(OCP) complex reacts with Ni(COD)2 to yield the heterobimetallic adduct (amid) 3 Th(μ-η 1 (O):η 2 (C,P)-OCP)Ni(COD) featuring an unprecedented reduced (OCP - ) bent fragment bridging the two metals.
