High resolution Fourier transform infrared spectra and analysis of the ν14, ν15 and ν16 bands of azetidine

High-resolution Fourier transform infrared synchrotron spectroscopy of the NO2 in-plane rock band of nitromethane

“…Synchrotron radiation at the CLS Far-Infrared (Far-IR) Beamline was used to record the FTIR spectrum of CH 3 NO 2 in the range 440-510 cm -1 . The Far-IR Beamline and its capability has been previously described [24][25][26][27][28][29][30]. Briefly, synchrotron infrared radiation is collected from the bending magnet via a slotted mirror and focused through a diamond window.…”

Analysis of high resolution FTIR spectra from synchrotron sources using evolutionary algorithms

“…Synchrotron-based measurements also allow routine access to wavelengths well into the far infrared region where vibrational frequencies are less accurately predicted and the observed spectra of even small molecules are very congested by hotbands or other complications. To test the robustness of the EA strategy for analyzing far infrared spectra, we have applied this technique to i) the ring puckering band of azetidine near 207 cm -1 which was previously analyzed 8 and known to be wellbehaved and ii) the newly recorded in-plane ring deformation band of trimethylene sulfide (TMS) near 529 cm -1 which is investigated here for the first time.…”

“…17 , 18 Synchrotron-based FTIR spectra have been used, for example, to derive the ring puckering potential of 3-oxetanone (c-C2H4(CO)O) 19 using its hotbands at ~140 cm -1 , to characterize the Coriolis interaction between overlapping bands in 2oxetanone 20 and to describe the coupling of NH inversion tunneling with ring inversion in the low-lying vibrations of azetidine (c-C3N6NH). 8 In the case of TMS, the pure rotational spectrum itself was complicated by the presence of ring inversion tunneling through a planar configuration corresponding to a barrier of ~274.2 cm -1 above the equilibrium, puckered geometry. 10 The a-type rotational transitions were thus tunneling doubled and assigned to the two ring inversion components of the ground vibrational state (0 + and 0 -).…”

The ν21 ring puckering mode of 3-oxetanone: A far infrared spectroscopic investigation using synchrotron radiation

“…These tools give direct and indirect information, respectively, about the vibrational energy spacing and have shown that molecules with similar backbones can have completely different ring puckering potentials associated with them. For example, the analogs of cyclobutane with silicon, oxygen and nitrogen substitution within the ring (silacyclobutane (c-C 3 H 8 Si) [7][8][9], oxetane (c-C 3 H 6 O) [10][11][12][13][14] and azetidine (c-C 3 H 6 NH) [15][16][17][18]) have very distinct potential forms. Silacyclobutane is a puckered ring and the double well potential has a large barrier ($440 cm À1 ) that gives rise to inversion tunneling doubling of the lowest energy states.…”