Knowledge Bank

High quality infared spectra of the two lowest frequency modes of azetidine (c-C$3$H$6$NH) have been recorded between 100 and 700 cm$\mathrm{<mrow\; data-mjx-texclass="ORD">-1</mrow>}$ using the far infrared beamline at the Candian Light Source in Saskatoon. The far infrared endstation couples highly spatially confined synchrotron light into a Bruker IFS125HR Fourier transform spectrometer and can achieve spectral resolution up to 0.000959 cm$\mathrm{<mrow\; data-mjx-texclass="ORD">-1</mrow>}$. The observed modes correspond to the ring puckering mode ($\nu 16$) at 207.2 cm$\mathrm{<mrow\; data-mjx-texclass="ORD">-1</mrow>}$ and the N-H bending mode ($\nu 15$) at 648.2 cm$\mathrm{<mrow\; data-mjx-texclass="ORD">-1</mrow>}$. Rotational analysis of the ring puckering mode confirmed our $ab$ $initio$ prediction that the band structure is governed by $a-$type selection rules rather than $c-$type transitions as reported for oxetane.} The results of the rovibrational analysis of both bands will be presented and comparisons will be made between the synchrotron spectra and those collected using a conventional globar source.