Synthesis and reactivity of an unsymmetrically substituted 16-membered macrocyclic complex of nickel(II) and the crystal structure of its acyclic precursor, (3-acetyl-10-methyl-5,9-diazatrideca-3,8-diene-2,12-dionato)nickel(II)

The synthesis of the new unsymmetrically substituted 16-membered macrocyclic complex, (3-acetyl-2,10,12-trimethyl-1, 5, 9, 13-tetraazacyclohexadeca-1, 3, 9, 11-tetra-enato)-Ni^II, by template-controlled macrocyclization is reported. This complex has a single nucleophilic site available to react with electrophilic reagents. The crystal structure of the acyclic precursor, (3-acetyl-10-methyl-5,9-diazatrideca-3,8-diene-2,12-dionato)Ni^II shows that in the solid state it exists as a pair of enantiomers, arising from the presence of two possible skew boat conformations adopted by the six-membered saturated metallochelate ring present in the molecule. © 1996 Chapman & Hall.