Thermal Stability of Encapsulated Molecular Structures with Extended OH-Hydrogen-Bond Chains

Alexander V. Savin

paper

Thermal Stability of Encapsulated Molecular Structures with Extended OH-Hydrogen-Bond Chains

arXiv:2609.10777

Abstract

Using a coarse-grained model, we performed numerical simulations of the dynamics of linear molecular chains adsorbed on a flat substrate (on the surface of an h-BN crystal). It is shown that molecules containing benzene rings and hydroxyl groups in their structure can form stable hydrogen-bond chains OH $\dots$ OH $\dots$ OH. Such chains can be formed by phenol C $_{6}$ H $_{5}$ OH, 4-phenylphenol C $_{6}$ H $_{5}$ --C $_{6}$ H $_{4}$ OH, paracetamol CH $_{3}$ C(O)NHC $_{6}$ H $_{4}$ OH, and 4-hydroxybenzanilide C $_{6}$ H $_{5}$ C(O)NHC $_{6}$ H $_{4}$ OH molecules. The dissociation of these chains occurs at temperatures above $T_{1} = 190$ , 240, 300, and 400K, respectively. Coating such molecular systems with a hexagonal boron nitride sheet (their van der Waals encapsulation) significantly enhances their thermal stability. Such encapsulated molecular structures retain hydrogen-bond chains up to temperatures of $T_{2} = 470$ , 800, 880, and 1140K, respectively. The simulations allow us to conclude that h-BN-encapsulated chains of these molecules can be used to create anhydrous proton-exchange membranes capable of operating at high temperatures. The most promising are encapsulated chains of paracetamol and 4-hydroxybenzanilide molecules.

13 pages, 15 figures, 5 tables