ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
Photolysis of NCO(X 2Π) at 193 nm leads to the production of CN(X 2Σ+ )+O(3 P). The CN(X) was detected by monitoring the CN X 2Σ+ →B 2Σ+ laser-induced fluorescence excitation spectrum. A spectral simulation calculation was used to obtain vibrational and rotational population distributions in the CN fragments. The fractional vibrational populations obtained in this manner are 0.43, 0.32, 0.21, and 0.04 for v=0, v=1, v=2, and v=3, respectively. The near-nascent rotational distributions in the different CN(X) vibrational levels are not characterized by a Boltzmann rotational temperature, but rather are bi-modal with maxima at both high and low N. The high N rotational excitation of the CN fragment suggests the existence of an excited dissociative state of NCO which is bent. A lower limit for the heat of formation of NCO, ΔHf 〉37 kcal/mol, is derived from the upper limit on the internal excitation of the CN(X) fragments. The spectrum of prompt emission produced by the 193 nm photolysis indicates the existence of a bound excited state of NCO which radiatively relaxes to the A 2Σ+ state. From the spectrum, this state is thought to be linear.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.457654
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