The hexaazamacrocycle 1,4,7,10,13,16-hexaazacyclooctadecane, [18]ane-N-6, forms mono- and dinuclear derivatives with copper chloride depending on the reaction stoichiometries and times. The mononuclear derivative, [Cu([18]ane-N-6)]Cl-2 center dot H2O, presents the macrocycle wrapped around the metal atom in a distorted octahedral coordinative environment, while the dinuclear derivative, [Cu-2([18]ane-N-6)Cl-2]Cl-2 center dot 4H(2)O, is formed by a central Cu2Cl2 core surrounded by an almost planar macrocycle. The crystal structure of both derivatives is stabilized by a network of hydrogen bonds involving the amine macrocyclic groups, the chloride anions, and the crystallization water molecules. The copper atoms in the dinuclear derivative show a strong antiferromagnetic coupling, as expected for the crystal structure parameters. A mononuclear nickel derivative has also been obtained from nickel nitrate by following the same synthetic procedure. These compounds react with TCNQ salts with formation of two types of derivatives, [M([18]ane-N-6)](TCNQ)(2) and [M([18]ane-N-6)](TCNQ)(4), depending on the use of radical-anionic or mixed-valence TCNQ salts in the reaction. The crystal structures of the nickel derivatives show that the former derivatives are built up by macrocyclic metal cations surrounded by dimeric dianions (TCNQ)(2)(2-), either isolated or stacked along the crystal. The derivative with four TCNQ units/formula consists of alternated chains of metallomacrocyclic cations and stacked TCNQ anions. The crystal parameters suggest that every TCNQ holds approximately 0.5 electrons and overlaps with a neighboring unit to form dimeric monoanions, (TCNQ)(2)(-).