Magnetism of cyano-bridged Ln3+-M3+ complexes.: Part II:: One-dimensional complexes (Ln3+ = Eu, Tb, Dy, Ho, Er, Tm; M3+ = Fe or Co) with bpy as blocking ligand

The reaction of Ln(No-3)(3(aq)) with K-3[Fe(CN)(6)] or K-3[Co(CN)(6)] and 2,2'-bipyridine in water/ethanol led to 13 one-dimensional complexes: trans-[M(CN)(4)(mu-CN)(2)Ln(H2O)(4)(bpy)](n)center dot 4nH(2)O center dot 1.5nbpy (Ln = Eu3+, Tb3+, Dy3+, Ho3+, Er3+, Tm3+, LU3+; M = Fe3+, Co3+). The structures for [EuFe](n) (1), [TbFe](n) (2), [DyFe](n) (3), [HoFe](n) (4), [ErFe](n) (5), [TmFe](n) (6), [LuFe](n) (7), [EuCo](n) (8), [TbCo](n) (9), [DyCo](n) (10), [HoCo](n) (11), [ErCo](n) (12), and [TmCo](n) (13) have been solved: they crystallize in the triclinic space group P! and are isomorphous. They exhibit a supramolecular architecture created by the interplay of coordinative, hydrogen bonding, and pi-pi interactions. A stereochernical study of the eight-vertex polyhedra of the lanthanide ions, based on continuous shape measures, is presented. The Ln(3+)-Fe3+ interaction is antiferromagnetic in [DyFe](n) and [TbFe](n). For [EuFe](n), [HoFe](n), [ErFe](n), and [TmFe](n), there is no sign of any significant interaction. The magnetic behavior of [DyFe], suggests the onset of weak long-range ferromagnetic ordering at 2.5 K.