Synthesis and Characterization of Coordination Polymers Based on Alkaline-Earth Metals, Copper(II), and Oxamate

This abstract describes the synthesis and characterization of novel coordination polymers using alkaline-earth metal ions (Ca²⁺, Sr²⁺, Ba²⁺) and the oxamate-based building block [Cu(opba)]²⁻. Single-crystal X-ray diffraction revealed that the calcium compound forms a 2D planar network, while the barium analogue exhibits a 3D porous structure with channels; the strontium compound also forms a 3D network but its formula remains undetermined. Infrared spectroscopy confirmed metal coordination to carbonyl groups through characteristic band shifts. Thermogravimetric analysis showed the calcium polymer is stable up to 135 °C, while strontium and barium compounds displayed additional mass losses suggesting moisture adsorption. The presence of channels in the barium structure indicates potential for gas storage applications, warranting further investigation.