hide
Free keywords:
1,6-DIYNES; NICKEL COMPLEXES
Abstract:
Displacement of the alkene ligand in Ligand-Ni(0)(1,6-diene) complexes by 1,6-heptadiyne, the parent 1,6-diyne, affords the complexes (Me3P)Ni(η2,η2-C7H8) (1) and (Ph3P)Ni(η2,η2-C7H8) (2). According to an X-ray structure analysis of the PMe3 derivative 1 the nickel atom is ideally trigonal-planar coordinated by the phosphane and both C≡C bonds. The increased stability of the complexes as compared to Ligand-Ni(HC≡CH)2 complexes is referred to the strong chelating effect which is special to the 1,6-functionalization. The compounds can be considered to be model complexes for the key intermediates of numerous transition metal-mediated coupling reactions of (substituted and unsubstituted) 1,6-diynes.
