Water structure at the interface of alcohol monolayers as determined by molecular dynamics simulations and computational vibrational sum-frequency generation spectroscopy.

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 are 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 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 may serve as benchmarks for further investigations to characterize ice nucleation induced by alcohol monolayers.