Trinuclear Nickel Complexes with Metal–Arene Interactions Supported by Tris- and Bis(phosphinoaryl)benzene Frameworks

Triphosphine and diphosphine ligands with backbones designed to facilitate metal–arene interactions were employed to support multinuclear Ni complexes. Di- and trinuclear metal complexes supported by a triphosphine containing a triarylbenzene linker display diverse metal–arene binding modes. Multinuclear Ni halide complexes were isolated with strongly interacting metal centers bound to opposite faces of the coordinated arene. Upon reaction of the trinickel diiodide complex 2 with disodium tetracarbonylferrate, a cofacial triangulo nickel(0) complex, 4, was isolated. The Ni03 cluster motif can also be supported by a para-terphenyl diphosphine, where a terminal carbon monoxide ligand replaces the third phosphine donor. All multinuclear complexes feature strong metal–arene interactions, demonstrating the use of an arene as a versatile ligand design element for small clusters.