Nickel (0) complexes of acyclic polyunsaturated aza ligands

Abstract

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