Structures and magnetic properties of several novel lanthanide coordination polymers based on thiophene-2,5-dicarboxylic acid

摘要

Eight novel lanthanide complexes: {Ln(TDA)1.5(H2O)2}n (Ln = Pr(1a), Nd(2a)) and {Ln(TDA)(Ac)(H2O)}n (Ln = Pr(1), Nd(2), Eu(3), Gd(4), Tb(5), Dy(6); TDA = Thiophene-2,5-dicarboxylic acid anion) have been constructed by hydrothermal reaction. Structural analyses reveal that complexes 1a and 2a belong to the space group C2/c, exhibiting three-dimensional (3D) frameworks. Complexes 1-6 with P21/c space group were prepared in the presence of excessive ammonium acetate, giving rise to interesting 3D frameworks different from those of 1a and 2a. Magnetic property studies of 4-6 reveal the weak antiferromagnetic interaction exists between adjacent Gd3+ in 4. The complex 6 displays rather rare slow magnetization relaxation behavior in 3D frameworks.