Dimeric Ni(II)2 and polymeric Ni(II)4Fe(II) type complexes bridged with Cl− and CN− ligands: X-ray structures and magnetic properties of a dimeric complex of [(tren)Ni(μ-Cl)2Ni(tren)](ClO4)2 and a polymeric complex of {[Fe(CN)6][Ni(tren)]2[Ni(tren)(H2O)]2

A dimeric complex of [(tren)Ni(μ-Cl)2Ni(tren)](ClO4)2 (1) and a polymeric complex of {[Fe(CN)6][Ni(tren)]2[Ni(tren)(H2O)]2}Cl2(ClO4)2·4H2O (2), are isolated from the reaction of potassium ferricyanide, nickel chloride and tren and their X-ray structures and magnetic properties were characterized. Two [Ni(tren)]2 + units are linked through bis μ-Cl ligands forming dimeric structure of 1. In complex 2, there are two kinds of Ni(II) unit, terminal ([Ni(tren)(H2O)]2 +) and bridged ([Ni(tren)]2 +), and this bridged [Ni(tren)]2 + units are linked with two different Fe(II) ions through μ-NC ligands forming one-dimensional polymeric rectangular chain. 1 shows a weak ferromagnetic coupling between two Ni(II) ions and 2 shows spin crossover in Fe(II) ion.