A coordination polymer of Na-Fe(III) with EDTA: synthesis, characterization, electrical conductivity, adsorption properties and Hirshfeld surface analysis

Abstract

In this work, we report Na-Fe(III) coordination polymer, Na[Fe(C₁₀H₁₂N₂O₈)(H₂O)]·2H₂O (1), derived from Ethylenediaminetetraacetic acid (EDTA) and the compound exhibits distorted octahedral coordination geometry. The polymeric structure is generated when octahedral sodium is connected with five oxygens comes from five EDTA molecules and one water molecule. The specific surface area (S_BET) of the compound was measured by Brunauer-Emmett-Teller (BET) which is 1036.9653 m²/g that value is consider as impressive. Further, thermal stability, sorption properties of nitrogen, water and benzene were also examined. In addition, electrical conductivity, the amount of ions and Hirshfeld surface analysis were also studied. The N₂ adsorption isotherm displays two distinct stages at low relative pressures (P/P₀ = 0-0.02), indicating the presence of two distinct types of nanopores within the material structure. In case of adsorption of water molecules, the adsorption capacity, reaching nearly 29 mol/kg, and achieves saturation at water vapor pressure while the benzene primarily adsorbs onto the outer surface of the sorbent material at 1.38 mol/kg but its adsorption capacity is lower in comparsion to water. This observation indicates that delineating the adsorption texture of the adsorbent material. The cleavage of certain bonds between the polymerized metal and the ligand in the coordination compound is confirmed through electrical conductivity and the amount of ions. The Hirshfeld surface analysis provided information about various types of surfaces interactions in this compound.