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.