State of the lithium ions in the sulfostyrene cation exchanger according to ab initio quantum chemical calculations

The structural parameters of the molecular model of a swollen sulfostyrene ion exchanger in lithium form were calculated. The calculations were performed using the non-empirical method (HF/basis using the Mini Huzinaga basis) and the Firefly software for the (RSO 3 Li) 2 - (H 2 O) 20 cluster. The distances between the Li + ions and the oxygen atoms in the cluster, which belong to the water molecules and sulfonic groups, were found and sorted in ascending order. The obtained data allowed one to establish that in the first molecular layer, strictly four oxygen atoms of water molecules are present around the Li + ion, and the ion itself does not form a direct bond with the sulfonic group. A sharp jump in the Li + -O distances takes place between the first and second molecular layers around the cation.