Simple synthetic protocol to obtain 3d-4f-heterometallic carboxylate complexes of N-heterocyclic carbenes

[Display omitted] •A new approach to NHC-substituted 3d-4f-heretometallic carboxylate complexes is suggested.•Co2La and Zn2Tb NHC complexes have been prepared.•Molecular structures of novel 3d-4f heterometallic trinuclear complexes are reported. A new approach to NHC-substituted 3d-4f-heterometallic complexes is suggested based on coordination of the free NHC with a pre-organized carboxylate 3d-4f-core. Following this route, two novel complexes with different heterometallic cores, Co2La and Zn2Tb, have been prepared.