Solvent-directed lanthanide 7,7,8,8-tetracyano-p-quinodimethane complexes: Syntheses, structures, magnetic and electrochemical properties

Reactions between trivalent lanthanide ions and the radical anion of 7,7,8,8-tetracyano-p-quinodimethane (TCNQ) produce four mononuclear complexes [Ln(TCNQ)2(H2O)7](TCNQ)·5H2O·EtOH [Ln = Nd (1), Sm (2), Eu (3) and Gd (4)] and three dinuclear complexes [Ln2(TCNQ)2(H2O)15](TCNQ)4·x(p-dioxane)·7H2O [Ln = Ce (5, x = 2.5), Pr (6, x = 2.5) and Nd (7, x = 2)]. One of the coordinated TCNQ− radical anions is involved in π–π stacking interactions with the uncoordinated TCNQ− radical anions, and the other coordinated TCNQ− radical anion is not involved in such π–π interactions in 1–4. All the TCNQ− radical anions are involved in π–π interactions in 5–7. The effect of reaction solvent on the structures of 1–7 was revealed. The magnetic properties of 4 and the electrochemical properties of 1–7 were investigated.