1,6‐Heptadien‐Nickel(0)‐Komplexe: rac /meso‐(μ‐η 2 ,η 2 ‐C 7 {Ni( η 2 ,η 2 ‐C 7 H 12 )} 2 und L‐Ni(η 2 ,η 2 ‐C 7 H 12 )

1,6‐Heptadiene Nickel(0) Complexes: rac/meso ‐(μ‐η 2 ,η 2 ‐C 7 {Ni(η 2 ,η 2 ‐C 7 H 12 )} 2 und L‐Ni(η 2 ,η 2 ‐C 7 H 12 ) Ni(CDT) dissolves in 1,6‐heptadiene with displacement of the CDT to yield the dinuclear homoleptic product rac / meso ‐(μ‐ η 2 ,η 2 ‐C 7 H 12 ){Ni(η 2 , η 2 ‐C 7 H 12 )} 2 ( 1 ) as a mixture of stereoisomers, in which the nickel atoms are trigonal‐planar coordinated by a chelating 1,6‐diene ligand and one CC bond of a bridging diene ligand. The stereoisomers differ in the coordination mode of the bridging diene ligand.‐The bridging diene ligand in 1 can be displaced by various donor/acceptor molecules. In pentane, 1 reacts with ethene to yield a solution of mononuclear (C 2 H 4 )Ni(η 2 ,η 2 ‐C 7 H 12 ) ( 2 ). With alkynes unstable complexes are formed of which the anticipated ethyne derivative (C 2 H 2 )Ni(η 2 ,η 2 ‐C 7 H 12 ) ( 3 ) decomposes explosively at – 100°C. With isocyanides, methylenephosphoranes, methyllithium, amines, pyridines, phosphanes, and phosphites (i.e. C, N, P donors) crystalline complexes of type L‐Ni(η 2 .η 2 C 7 H 12 ) have been obtained, of which the derivatives with L= t BuN C 4, Me 3 PCH 2 5 , LiCH 3 6 , C 7 H 13 N 7 , C 5 H 5 N 8 , Me 3 P 9 , i Pr 3 P 10 , Ph 3 P 11 , (PhO) 3 P 12 are characterized here. For 11 the crystal structure has been determined.