1,2,3- and 1,2,4-Benzenetricarboxylic ligands: investigation of unusual 2D and 3D polymeric nets with potassium ion

The present work presents a description of two unusual polymeric nets containing potassium (I) and benzenetricarboxylic ligand with formula [K(C9H5O6)·H2O] (1) and [K(C9H5O6)·(H2O)2] (2). Their structures were solved by single crystal X-ray diffraction methods. The structural results suggest that the interactions between carboxylate groups and potassium ion have an ionic character and they are similar for both compounds. The study of the chemical bond between the oxygen and potassium atoms was performed for compound 2 through density functional theory calculations and confirmed that compound 2 is stabilized by ionic interactions, which can be associated analogously to compound 1. The organization of these interactions into crystal packing was investigated by program package TOPOS4.0. It was found that these interactions play an important role in the construction of the 3D and 2D polymeric net for both compounds.