Water Structure at the Interface of Alcohol Monolayers as Predicted by Computational Vibrational Sum-Frequency Generation Spectroscopy

In this study, we investigate the structure of water at the interface of three long-chain alcohol monolayers differing in alkyl chain length through molecular dynamics simulations combined with modeling of vibrational sum-frequency generation (vSFG) spectra. The effects of alkyl chain parity on interfacial water is examined through extensive analysis of structural properties, hydrogen bonding motifs, and spectral features. Besides providing molecular-level insights into the structure of interfacial water, this study also demonstrates that, by enabling direct comparisons with experimental vSFG spectra, computational spectroscopy may be used to test and validate force fields commonly used in biomolecular simulations. The results presented here can thus serve as benchmarks for both further investigations to characterize ice nucleation induced by alcohol monolayers and refinement of popular biomolecular force fields.