Hexaazaphenalenyl Anion Revisited: A Highly Symmetric Planar π System with Multiple-Networking Ability for Self-Assembled Metal Complexation

The hexaazaphenalenyl anion (HAP, 3-), a highly symmetric
heterocyclic π system, has been synthesized and characterized.
The crystal structures of its potassium salt K+·3- and copper complex Cu2+·(NH3)4·(3-)2 show π−π 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.