Modeling of orthosilicate and methanesulfonic acid clusters in aqueous solution

In the work using the quantum-chemical modeling method, the possibility of binding orthosilicate acid with different amounts of methanesulfonate anions was considered. It was demonstrated that methanesulfonic acid forms two hydrogen bonds with a molecule of orthosilicate acid, regardless of the conformation of the cluster itself. According to the results of calculations of energy parameters of systems and frontier molecular orbitals, it was established that the most stable cluster of orthosilicate acid with methanesulfonate anion is [H4SiO4 · 4CH3SO3–]. It was also established that the formation of an eight-membered cycle (S–O···H–O–Si–O–H···O) and (S–O···H –O–Si–O···H–С). Furthermore, it was established that there is no significant dependence of the effective charge on the silicon atom on the number of methanesulfonate anions in the inner sphere. Thus, it is theoretically demonstrated that the methanesulfonate anion is able to stabilize orthosilicate acid and reduce the possibility of its dimerization.