Hexaazaphenalenyl anion revisited: a highly symmetric planar pi system with multiple-networking ability for self-assembled metal complexation

The hexaazaphenalenyl anion (HAP, 3-), a highly symmetric heterocyclic pi system, has been synthesized and characterized. The crystal structures of its potassium salt K+.3- and copper complex Cu2+.(NH3)4.(3-)2 show pi-pi stacking and radially extended hydrogen bonds as well as coordination bonds constructed by the HAP anion. These in-plane and out-of-plane strong interactions demonstrate the multiple-networking ability of the HAP anion.