Syntheses, Structures, and Magnetic Properties of Five Novel Octacyanonnetallate-Based Lanthanide Complexes with Helical Chains

The reactions of octacyanometallates [M(CN)(8)](3-) (M = Mo, W) and lanthanide ions Ln(3+) (Ln = Pr, Sm, Eu) through the solution diffusion method in the presence of chelated aromatic ligands 1,10-phenanthroline (phen) or 3,4,7,8-tetramethy1-1,10-phenanthroline (tmphen) have yielded five new [M(CN)(8)](3-)-based bimetallic complexes with helical structures: [Ln(phen)(2)(H2O)Mo(CN)(8)](2)[(n-C4H9)(4)N](NO3)center dot 2CH(3)CN center dot 4H(2)O [Ln = Sm(1), Eu(2)], [Sm(tmphen)(2)(DMF)(2)][W(CN)(8)]center dot 2H(2)O (3), and [Pr(tmphen)(DMF)(3)][M(CN)(8)]center dot DMF center dot 2H(2)O [M = Mo(4), W(5)]. The Ln(3+) centers are linked alternately by [M(CN)(8)](3-) units through two trans V-shaped cyano groups to form the left- and right-handed helical chains running along the screw axis. Magnetic measurements revealed the presence of an antiferromagnetic interaction between metal centers in 4 and S.