Lanthanide-3d cyanometalate chains Ln(III)-M(III) (Ln = Pr, Nd, Sm, Eu, Gd, Tb; M = Fe) with the tridentate ligand 2,4,6-tri(2-pyridyl)-1,3,5-triazine (tptz): evidence of ferromagnetic interactions for the Sm(III)-M(III) compounds (M = Fe, Cr)

A series of cyanide-bridged chain mixed Fe(III)/Ln(III) (Ln = Pr, Nd, Sm, Fu, Gd, Tb) complexes with the tridentate ligand 2,4,6-tri(2-pyridyl)-1,3,5-triazine (tptz) used as a capping group has been prepared. Reactions of tptz and LnCl(3) with K3Fe(CN)(6) yield a family of air-stable 1-D compounds {[Pr(tptz)-(H2O)(4)Fe(CN)(6)]center dot 8H(2)O}(infinity) (1), {[Nd(tptz)(H2O),Fe(CN)(6)]center dot 8H(2)O}(infinity) (2), {[Sm(tptz)(H2O)(4)Fe(CN)(6)]center dot 8H(2)O}(infinity) (3), {[Eu(tptz)(H2O)(4)Fe(CN)(6)]center dot 6H(2)O}(infinity) (4), {[Gd(tptz)(H2O)(4)Fe(CN)(6)]center dot 6H(2)O}(infinity) (5), and {[Tb(tptz)(H2O)(4)Fe(CN)(6)]center dot 8H(2)O}(infinity) (6). Temperature dependent magnetic susceptibility studies of 1-6 reveal that in 3, the Sm(III) and Fe(III) ions are ferromagnetically coupled with 3-D ordering occurring below 3.5 K. The appearance of the frequency dependent out-of-phase signal is explained in terms of an ordering with a spin glass-like behavior. To compare the magnetic behavior of 3 with related compounds, {[Sm(tptz)(H2O)(4)Co(CN)(6)]center dot 8H(2)O}(infinity) (7) and {[La(tptz)(DMF)(H2O)(3)Fe(CN)(6)]center dot 5H(2)O}(infinity) (8), {[Sm(tmphen)(DMF)(3)(H2O)Fe(CN)(6)]center dot 2H(2)O}(infinity) (9), {[Sm(tmphen)(2)(H2O)(2)Fe(CN)(6)]center dot MeOH center dot 13H(2)O}(infinity) (10) and {[Sm(tmphen)(2)(H2O)(2)Cr(CN)(6)]center dot MeOH center dot 9H(2)O}(infinity) (11) with 3,4,7,8-tetramethyl-1, 10-phenanthroline (tmphen) were also prepared.