The nickel(II) and copper(II) polyamine derivatives are adequate fragments to interact with the organic acceptor TCNQ, favoring the formation of σ bonds between the metal atom and the TCNQ nitrile groups. In its radical anion form, this molecule tends to form dimeric dianions (TCNQ) 2 2 - by overlapping of the π cloud with a neighboring radical. When the metal has a stable and coordinatively saturated environment these dianions remain uncoordinated, but if the metal has vacant positions or labile ligands formation of two M-TCNQ bonds is observed. In these cases the dianions are bridging two metal units forming infinite chains. In the dimers, the radicals are strongly antiferromagnetically coupled behaving as diamagnetic units. These compounds with localized electrons behave as insulators, or poor semiconductors. In its neutral form the TCNQ has a low coordinative ability, but its presence favors the overlap of the dianionic dimers to form infinite stacks. When both neutral and radical-anionic TCNQ are present in the reaction mixture the derivatives obtained usually have three TCNQ molecules per metal atom. Depending on the interactions between the TCNQ and the metal two situations are found: if all the TCNQ molecules are uncoordinated the electronic charge on the organic stack is delocalized, but if direct bonding to the metal is present, the bonded molecules show radical anion characteristics, while the uncoordinated TCNQ behave as neutral molecules. The presence of this neutral TCNQ weakens the coupling in the (TCNQ) 2 2 - dimers and a temperature dependent contribution from the TCNQ to the magnetic susceptibility is found. These compounds having mixed valence TCNQ units show a greater electronic delocalization and behave as good semiconductors with higher conductivity values and lower activation energies in the derivatives that do not show direct bonding between the metal and the TCNQ.