H-bonding behavior of ethylene oxide within the clathrate hydrates revisited: Experiment and theory

[Display omitted] •H-bonding behavior of ethylene oxide in the clathrate hydrates have been reanalyzed.•NH3 was used to promote H-bonding behavior of ethylene oxide.•Classical and nonclassical vibrational modes of ethylene oxide were assigned. FTIR spectroscopy has been used to reexplore the nonclassical behavior of ethylene oxide (EO) within the large cages of clathrate hydrates. In most of the spectroscopic studies of EO within the clathrate hydrate cages, the classical EO bands attributed to the C-O stretch mode of EO were misassigned. Therefore, the all-vapor sub-second approach to clathrate-hydrate formation combined with computational studies was used to reexamine spectroscopic characteristics of EO molecules in which they can be either in classical or nonclassical forms.