pH Effect on Hydrothermal Synthesis of the Coordination Polymers Containing Pyrazine-2,3-dicarboxylate: Investigation of Thermal Stability, Luminescence, and Electrical Conductivity Properties

Abstract

Hydrothermal reactions of the lanthanide(III) salt with 2,3-pyrazinedicarboxylic (2,3-pzdc)acid yielded the coordination polymers [La2(2,3-pzdc)3(H2O)]n.3nH2O (1) and [La2(2,3-pzdc)3(H2O)]n.2nH2O (2). Compounds were obtained in a three dimensional form with different pH valuesunder subcritical water conditions. The structures had variable coordination numbers. In addition, pHvalues play an important role in the structural chemistry of these materials. Different characterizationtechniques (elemental analysis, FT-IR, ICP-OES, TG/DTA, FESEM, PXRD, BET and single crystal X-ray)were carried out to confirm crystallinity, porosity, purity and chemical composition of the coordinationpolymers. Crystal structures of the polymers were examined in detail. Their thermal stability,luminescence and electrical conductivity properties were investigated in the solid state.