TY - JOUR
T1 - NO (A) Rotational State Distributions from Photodissociation of the N2-NO Complex
AU - Parsons, Bradley F.
AU - Rivera, Marcos R.
AU - Onder, Michael K.
N1 - Funding Information:
This work was supported by a Nebraska NASA EPSCoR Research Mini-Grant and by the Betty and Donald J. Baumann Family Fund for Research and Outreach. B.F.P. gratefully acknowledges financial assistance through a CURAS Summer Faculty Research Fellowship from the College of Arts and Sciences at Creighton University. Finally, we thank Professor Donald Levy and the Department of Chemistry at the University of Chicago for donating the Spectra Physics dye laser used for these experiments.
Publisher Copyright:
© 2022 American Chemical Society. All rights reserved.
PY - 2022/9/1
Y1 - 2022/9/1
N2 - We have recorded the resonance-enhanced multiphoton ionization spectrum for NO (A) products from photodissociation of the N2-NO complex. We made measurements at excitation energies ranging from 28 to 758 cm-1above the threshold to produce NO (A) + N2(X) products, and the resulting spectra reveal the NO (A) rotational states formed during dissociation, allowing us to determine the rotational state distribution. At the lowest available energies, 28 and 50 cm-1above threshold, we observed contributions from NO (A) rotational states that exceed the available energy and must originate from excitation due to hotbands of the complex. At all higher energies, we did not observe any energetically disallowed NO (A) rotational states, and for all available energies above 259 cm-1the observed rotational transitions do not extend to the maximum allowed by energy conservation. Furthermore, the observed distributions were typically biased toward low rotational states, in contrast with expectations from vibrational predissociation. From the rotational state distributions, we determined the average fraction of energy partitioned into NO (A) rotation, fNO rot, ave, to be 0.088 at the highest available energy, and this fraction increased as the available energy decreased. By combining the average NO (A) rotational energy along with the average center-of-mass translational energy from our previous work, we determined the average rotational energy for the undetected N2(X) photoproduct. The results showed that the N2fragment has a higher average rotational energy relative to the NO fragment. Finally, we found that the NO (A) rotational state distribution was colder than expected for a statistical dissociation.
AB - We have recorded the resonance-enhanced multiphoton ionization spectrum for NO (A) products from photodissociation of the N2-NO complex. We made measurements at excitation energies ranging from 28 to 758 cm-1above the threshold to produce NO (A) + N2(X) products, and the resulting spectra reveal the NO (A) rotational states formed during dissociation, allowing us to determine the rotational state distribution. At the lowest available energies, 28 and 50 cm-1above threshold, we observed contributions from NO (A) rotational states that exceed the available energy and must originate from excitation due to hotbands of the complex. At all higher energies, we did not observe any energetically disallowed NO (A) rotational states, and for all available energies above 259 cm-1the observed rotational transitions do not extend to the maximum allowed by energy conservation. Furthermore, the observed distributions were typically biased toward low rotational states, in contrast with expectations from vibrational predissociation. From the rotational state distributions, we determined the average fraction of energy partitioned into NO (A) rotation, fNO rot, ave, to be 0.088 at the highest available energy, and this fraction increased as the available energy decreased. By combining the average NO (A) rotational energy along with the average center-of-mass translational energy from our previous work, we determined the average rotational energy for the undetected N2(X) photoproduct. The results showed that the N2fragment has a higher average rotational energy relative to the NO fragment. Finally, we found that the NO (A) rotational state distribution was colder than expected for a statistical dissociation.
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U2 - 10.1021/acs.jpca.2c04265
DO - 10.1021/acs.jpca.2c04265
M3 - Article
C2 - 35994689
AN - SCOPUS:85137138887
VL - 126
SP - 5729
EP - 5737
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
SN - 1089-5639
IS - 34
ER -