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

► The first asymmetrical tetraazacyclo[15]annulene nickel(II) complexes are template synthesized. ► The crystal structures of macrocycle-nickel(II) complexes was determined. ► The structure around nickel exhibits a slightly distorted square planar with overall saddle-shaped.