A novel three dimensional samarium(III) coordination polymer with an unprecedented coordination mode of the 2,5-pyridinedicarboxylic acid ligand: Hydrothermal synthesis, crystal structure and luminescence property

Abstract

A novel three dimensional (3D) coordination polymer [Sm(pic)2(pydc)4(H2O)]n (pydc=pyridine-2,5-dicarboxylate, Hpic=picolinic acid) (1) has been synthesized hydrothermally and characterized by elemental analysis, FT-IR, TG/DTA, single-crystal X-ray diffraction analysis and powder X-ray diffraction (PXRD). This compound crystallizes in the monoclinic space group P21/c with cell parameters a=9.3041(13)Å, b=14.216(2)Å, c=10.5401(15)Å, V=1387.72(30)Å3 and Z=4. Complex 1 has a distinct 3D open-framework architecture due to the presence of picolinic ligands, which are converted from 2,5-pydc ligands by in-situ decarboxylation under the hydrothermal conditions. The compound exhibits strong luminescent emissions because of the f-f transitions of the Sm(III) ion at room temperature. According to TGA/DTA analysis, the coordination polymer is thermally stable up to ∼300°C.