Template synthesis and X-ray crystal structures of 15-membered unsymmetric monobenzotetraazaannulene nickel(II) complexes

New nickel(II) complexes A and B having macrocyclic ligands 4,10-dimethyl-2,12-diphenyl-1,5,9,13-dimethylbenzotetraazacyclo[15]tetradecine and 4,10-dimethyl-2,12-diphenyl-1,5,9,13-nitrobenzotetraazacyclo[15]tetradecine, respectively, have been synthesized and characterized by spectroscopic methods, including single-crystal X-ray diffraction. The nickel and four nitrogen atoms in both of the unsymmetrical tetraaza[15]annulene-ligated complexes have a slightly distorted square-planar arrangement rather than a square-pyramidal one, despite ring strain from coordination with the propylenediamine group. (C) 2013 Elsevier B.V. All rights reserved.