New infrared spectra of the nitrous oxide trimer

Abstract

Infrared spectra of N(2)O trimers are studied using a tunable diode laser to probe a pulsed supersonic slit-jet expansion. A previous observation by Miller and Pedersen [J. Chem. Phys. 108, 436 (1998)] in the N(2)O nu(1)+nu(3) combination band region ( approximately 3480 cm(-1)) showed the trimer structure to be noncyclic, with three inequivalent N(2)O monomer units which could be thought of as an N(2)O dimer (slipped antiparallel configuration) plus a third monomer unit lying above the dimer plane. The present observations cover the N(2)O fundamental band regions nu(3) ( approximately 1280 cm(-1)) and nu(1) ( approximately 2230 cm(-1)). In the nu(3) region, two trimer bands are assigned with vibrational shifts and other characteristics similar to those in the nu(1)+nu(3) region, but in the nu(1) region all three possible trimer bands are observed. Relationships among the various bands are considered with reference to their rotational intensity patterns, their vibrational shifts, and the properties of the related N(2)O dimer, with results that generally support the conclusions of Miller and Pedersen. Three trimer bands are also observed for the fully (15)N-substituted species in the nu(1) region, and these results should aid in the detection of the as-yet-unobserved pure rotational microwave spectrum of the trimer.

Rovibrational spectrum and potential energy surface of the N2–N2O van der Waals complex

“…This discrepancy is still not understood. Other van der Waals complexes or clusters formed in the supersonic expansion of He/N 2 /N 2 O, such as He-N 2 O [7], (N 2 O) 2 [15] and (N 2 O) 3 [16], are also possible to be detected in the N 2 O m 1 region. No transitions of He-N 2 O were identified due to the relatively high rotational temperature in our jet.…”

High-resolution infrared spectroscopy of carbon dioxide dimers, trimers, and larger clusters

“…All the spectra were recorded by direct absorption using a rapid-scan tuneable diode laser spectrometer at The University of Calgary, as described previously [33][34][35][36]. Wavenumber calibration was ensured by simultaneously recording signals from a fixed etalon and a room temperature reference gas cell, which was usually filled with CO 2 or N 2 O. Spectra were assigned, simulated, and fitted using Colin Western's computer program PGOPHER [37].…”

Infrared spectra of two isomers of OCS–C2H2 and OCS–C2D2 in the region of OCS ν1 fundamental

“…Some complexes have been studied spectroscopically in both the microwave and infrared regions, such as polar (N 2 O) 2 [1][2][3][4], polar (OCS) 2 [5,6], (OCS) 3 [7,8], (C 2 H 2 ) 2 [9,10], OCS-CO 2 [11,12], CO 2 -N 2 O [13][14][15], CO 2 -C 2 H 2 [16,17], and N 2 O-C 2 H 2 [18][19][20][21][22]. Others have been studied only by means of their infrared spectra, either because of their nonpolar structure like nonpolar (N 2 O) 2 [4,[23][24][25][26][27], nonpolar (OCS) 2 [28,29], and (CO 2 ) 2 [30,31], or because of complications arising from extensive hyperfine structure, like (N 2 O) 3 [32,33]. Still other complexes have hitherto been studied only by microwave spectroscopy, for example the subject of the present paper, OCS-C 2 H 2 , which occurs as two distinct isomers as shown by Peebles and Kuczkowski [34,35].…”