Coordination of a Phosphine‐Tethered Aminoborane to Group 10 Metals

Abstract

While π‐complexes of C=C bonds are ubiquitous in organometallic chemistry, analogous complexes of the isoelectronic but strongly polarized B=N double bond of aminoboranes are extremely scarce. To address this gap, a diphosphine‐aminoborane ligand (PhDPBAiPr) is introduced and its coordination with group 10 metals is investigated. The B=N bond does not coordinate to the metal in Pt(0) and Pd(II) complexes. In contrast, side‐on coordination of the B=N bond is observed in the Ni(0) complex [PhDPBAiPr]Ni(NCPh), and the X‐ray crystal structure reveals B—N bond elongation compared to the free ligand. The choice of co‐ligand strongly influences the presence or absence of side‐on coordination at Ni(0) as evidenced by NMR spectroscopy. While the B=N π‐complex is geometrically similar to C=C analogues, a bonding analysis reveals that the interaction of the B=N motif with the electron‐rich Ni(0) center is best described as 3c4e hyperbond, in which Ni and N are competing for the empty orbital on B.