Template condensation reactions of formaldehyde with tetraamines and ethylenediamine: preparation, properties, and structures of nickel(II) and copper(II) complexes of hexaaza macrotricyclic ligands 1,3,6,8,11,14-hexaazatricyclo[12.2.1.18,11]octadecane and 1,3,6,8,12,15-hexaazatricyclo[13.3.1.18,12]