Synthesis and investigation of the metal-metal interactions in early/late heterobimetallic complexes linking group 5 imido fragments to Co(I).

Phosphinoamide ligands have been utilized to link a Co(I) center to a Nb or Ta imido fragment. The resulting heterobimetallic complexes, ICo(Ph(2)PN(i)Pr)(3)M=N(t)Bu, have weakened dative metal-metal interactions as a result of the strongly donating imido ligand. These complexes can be reduced by 2 electrons to generate dinitrogen-bound complexes.