A trans-spanning diphosphine ligand based on a m-terphenyl scaffold and its palladium and nickel complexes

作者：Smith RC; Protasiewicz JD^*

来源：Organometallics, 2004, 23(18): 4215-4222.

DOI：10.1021/om049662d

The new diphosphine ligand 2,6-bis(2-((diphenylphosphino)methyl)phenyl)benzene (1) has been prepared for potential use as a terdentate pincer-type ligand. Upon examination of the coordination chemistry with representative palladium and nickel centers, however, it was discovered that it acts as a bidentate trans-spanning ligand upon coordination to form trans-[(1)PdCl2] (2) and trans- [(1)NiCl2] (3). Attempts to promote CH activation of the central benzene ring and produce a terdentate pincer binding mode for 1 were unsuccessful. Reaction of 2 and [Li(OEt2)][B(C6F5)(4)] led to formation of the dicationic bis(chloro)-bridged dimer [(1)(2){Pd-2(mu(2)-Cl)(2)}][B(C6F5)(4)](2) (4), in which two ligands 1 have rearranged to span across the dichlorodipalladium core. The structures of air- and moisture-stable 2-4 were confirmed by X-ray crystallography.

• 出版日期2004-8-30