The modelling by the methods of molecular dynamics of influence of zeolites with (Na<sup>+</sup><sub>x</sub>(H<sub>2</sub>O)<sub>y</sub>)[Al<sub>a</sub>Si<sub>b</sub>O<sub>c</sub>], Ca<sub>x</sub>[H<sub>2</sub>O]<sub>y</sub>Al<sub>a</sub>Si<sub>b</sub>O<sub>c</sub>, Si<sub>x</sub>O<sub>y</sub>) framework types on formation of 4-alkyl-1,3-dioxanes by Prins reaction
By the methods of molecular dynamics using universal force field, the authors of the article showed the possibility of selective stabilization of transition state in the process of formation of 4-alkyl-1,3-dioxanes by Prins reaction in the presence of zeolites with (Na<sup>+</sup><sub>x</sub>(H<sub>2</sub>O)<sub>y</sub>)[Al<sub>a</sub>Si<sub>b</sub>O<sub>c</sub>], Ca<sub>x</sub>[H<sub>2</sub>O]<sub>y</sub>Al<sub>a</sub>Si<sub>b</sub>O<sub>c</sub>, Si<sub>x</sub>O<sub>y</sub>) framework types. As the model alkenes, ethylene, propylene, isobutylene, butane-1, and butane-2 were used. For the relevant transition states, the interaction energy between frozen TS and zeolite’s pores was estimated. The character of interaction and the TS stabilization energy on materials with active surface were determined via Adsorption Locator module for Accelrys Material Studio 5.5 software with universal force field. The used structure of the transition states corresponds to the addition reaction of formaldehyde dimer over a multiple bond of an alkene. The expected course of this reaction was established in the previous study of the authors. The stabilization energy depends on pore diameter and has extreme character. The most significant stabilization is achieved, when the pore diameter is comparable with size of transition state. The framework type of zeolite has no significant influence on stabilization effect and pore diameter of zeolites, when the stabilization is at its maximum. According to the calculated data, the optimum diameter of zeolite’s pores of considered groups is placed between 6÷7.5 Å.