Tetraazamacrocyclic Nickel(II) Complexes Containing a Pendant Amino Group

Reduction of the nitro group in 5-nitromethyl-1,4,8,11-tetraazacyclotetradeca-11-enenickel(II) complexes 1 leads to 5-aminomethyl-substituted macrocyclic nickel(II) complexes. Orange, protonated “arm off” (3 and 5) and violet “arm on” (2 and 4) complexes were isolated and characterized. Relative configurations of substituents and conformations of the macrocyclic ligands are proposed on the basis of NMR evidence. The isolation of free ligands is also described.