Abstract
The presented work is focused on preparation and characterization of Metal-Organic Framework (MOF) with the chemical formula {[Pr-4(H2TPPS)(3)] . nH(2)O}(n). This type of polymer was synthesized via hydrothermal reaction with Pr(NO3)(3) . 6H(2)O and porphyrinic ligand H2TPPS (where H2TPPS = 4,4',4'',4''-(porphine-5,10,15,20-tetrayl)tetrakisbenzenesulfonate).
Prepared MOF was characterized by single-crystal X-ray diffraction, infrared spectroscopy, thermal and elemental analysis, and the magnetic susceptibility measurement. The crystal structure of prepared MOF is formed from Pr(III) ions arranged in 1D chains bridged by four H2TPPS ligands forming the final 3D framework with opening size 4.9x10.4 angstrom(2) and 9.7x5.1 angstrom(2), which are filled with water molecules.
The magnetic properties of the coordination polymer were studied by magnetic susceptibility chi(M)(T), and magnetization M(H) measurements in an external dc field up to 7 T in the temperature range from 1.8 to 300 K. The experimental results revealed a significant reduction of the magnetic moment below 50 K as an evidence of the presence of low-lying quasi-doublet in the energy spectrum of Pr ion in {[Pr-4(H2TPPS)(3)] . nH(2)O}(n).