Nano-Synthesis of Crystalline 3D-Zr-Cluster-Porous Coordinated Polymer for CO2-Capture

Abstract

Novel crystalline Zr(IV)-syn-3,4,6,7-tetramethyl-1,5-diazabicyclo(3.3.0)-octa-3,6-diene-2,8-dione porous coordinated polymers (PCPs) were successfully synthesized via advanced microwave assisted hydrothermal technique in 33 min. The present studies are aiming to optimize experimental conditions of the newly Zr(IV)- complex formation which is the initial monomeric precursor for Zr-PCPs. The molecular modeling studies of the principle ligand predicted by a two different stabilized geometrical positions can present together inside the crystal lattice of the produced 3D-Zr-PCPs. One of these two orientation models (Zigzag-like structure) which has strong priority to form disordered Zr-PCPs. The theoretical calculations of bond distances, indicated by existence of zirconium ions with average ionic radii of ~ 1.09Å (i.e. bond length of Zr⁴⁺-O = 2.18Å) which is very near to the (octa-coordinated zirconium with ionic redii ~ 0.98Å), due to presence of elongated bond distances between Zr-O inside unit cell. Furthermore, the synthesized crystalline Zr-complex was carefully characterized via micro-elemental analysis (C, H, O, N and M), XRD, SEM, 3D-AFM, Uv-Vis. as well as BET-specific surface area which was found relatively high of ~ 2125m²g^− 1. The synthesized Zr- PCPs exhibited substantially stronger CO₂ adsorption with maximum adsorption capacity of 2.61mmol/g at 273 K and 1 bar.