Nickel(0) Complexes of Acyclic Polyunsaturated Aza Ligands

The acyclic 4,9-bis­(4-tolylsulfonyl)-4,9-diazadodeca-1,11-dien-6-yne
(1) and 4,9-bis­(4-tolylsulfonyl)-4,9-diazatrideca-1,(E)-6-dien-11-yne (2), which differ in the sequence
of the two ene and one yne functions in the chain, have been reacted
with 1 and 2 equiv of Ni­(cod)2. The reaction with 1 equiv
of Ni­(cod)2 affords the mononuclear trigonal-planar nickel(0)
complexes 3 and 5. These react with a further
1 equiv of Ni­(cod)2 by addition of a Ni­(cod) entity to
give the dinuclear derivatives 4 and 6.
While 3 forms a mixture of isomers C2-3 and Cs-3 in solution, C2-3 is exclusively present in the crystal,
where it is packed in parallel columns. Complex 6 crystallizes
as a spherulite. Complexes 3–6 have
been characterized by NMR and single-crystal X-ray structure analysis,
and a detailed conformational analysis is given.