Far-infrared spectra and two-dimensional potential energy surfaces involving the ring-puckering vibration of 2,5-dihydrothiophene

A study was conducted to analyze potential energy surfaces involving the ring-puckering vibration of 2,5-dihydrothiophene. Far-infrared spectra were determined using a Digilab FTS-20E spectrometer supporting a helium-cooled bolometer detector. The samples were stored in a Wilkes variable long-path cell with variable path lengths of 4 to 20 m. In addition, the interaction between the puckering and the in-plane ring angle bending was examined.