Crystal structure and magnetic properties of lanthanide-trans-2-butenoate polymers (Ln = La, Pr, Dy, Ho)

Abstract

Four lanthanide coordination polymers formulated as {[La3L9(H2O)(3)](EtOHH2O)-H-.}(n)1,{[Pr2L6(H2O)(2)](HLH2O)-H-.}(n)2,{[Dy2L6(H2O)]0.5HL(.)H(2)O}n 3 and {[Ho2L6(H2O)]0.5HL.H2O}(n) 4 and HL = trans-2-butenoic acid have been synthesized from the corresponding pure lanthanide oxide and HL acid in water at pH 3. The compounds were characterized by chemical analysis, IR spectroscopy, thermogravimetry, variable-temperature magnetic susceptibility and single crystal X-ray diffraction studies. A common feature in these materials is the presence of two differentiated lanthanide nodes linked by carboxylates into extended chains. These are further connected by inter- and intra-molecular hydrogen-bonds involving ligand and solvate molecules. Weak ferromagnetic interactions appear to be operative in the Dy material.