Unravelling hydrogen bond network in methanol-propanol mixtures via molecular dynamics simulation and experimental techniques

ABSTRACTHydrogen-bonded networks in 1-propanol-methanol binary mixture are studied using molecular dynamics simulation along with experimental techniques (FTIR, dielectric spectroscopy and refractive index measurements) for the entire concentration range. The structure of hydrogen-bonded networks is studied through radial distribution function, hydrogen bond statistics and graph theoretical analysis from molecular dynamics. It is observed that the probability of hydrogen bonding is maximum in methanol molecules followed by hydrogen bonding between methanol and 1-propanol molecules and minimum among 1-propanol molecules, as the concentration changes. The graph theory results show the formation of linear chain hydrogen bond networks, with no caged structures, which is validated from the experimental results. Further, the deconvolution of the FTIR OH peak suggests the presence of linear multimers in all concentrations of the binary system. Average degree of the hydrogen-bonded networks from graph theory indicates a complex networks among pure alcohols and dimers between methanol and 1-propanol in their binary mixtures at all concentrations. The negative values of excess permittivity indicate that the components of the mixture interact in a manner such that the net dipole polarisation decreases.KEYWORDS: Hydrogen bond networkbinary mixturesFTIRmolecular dynamic simulationgraph theory AcknowledgmentsThe authors acknowledge the use of the Inter-University Center for Astronomy and Astrophysics (IUCAA) server to run the MD simulations. S P V acknowledges DST, Govt. of India for the Inspire Fellowship (IF190317). AU acknowledges the Central University of Tamil Nadu, India for providing university fellowship.Disclosure statementNo potential conflict of interest was reported by the authors.Author contributionsVM conceived the original idea; ARMK and AU performed all the simulations; SK and SPV conducted the experiments. All the authors were involved in the analysis of the results and contributed equally to the consolidation of results, writing and editing of the manuscript.Data availability statementThe datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.Supplemental dataSupplemental data for this article can be accessed online at https://doi.org/10.1080/00319104.2023.2263897.Additional informationFundingThe authors declare that no funds, grants or other support were received during the preparation of this manuscript.