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First far-infrared high resolution analysis of the ν2 and ν4 bands of phosgene 35Cl2CO and 35Cl37ClCO



Walter J. Lafferty, Jean-Marie Flaud, Fridolin Kwabia Tchana, Agnes Perrin, Laurent Manceron, Mustafa Ndao


A Fourier transform spectrum of phosgene (Cl2CO) has been recorded in the 17.3 μm spectral region at a temperature of 180 K and at a resolution of 0.00102 cm-1 using a Bruker IFS125HR spectrometer coupled to synchrotron radiation leading to the observation of the ν2 and ν4 vibrational bands of the two isotopologues 35Cl2CO and 35Cl37ClCO. The corresponding upper state ro-vibrational levels were fit using a Hamiltonian model accounting for the a-type Coriolis interaction linking the rotational levels of the 21 and 41 vibrational states. In this way it was possible to reproduce the upper state ro-vibrational levels to within the experimental uncertainty i.e. ~0.30×10-3 cm-1. Very accurate rotational, centrifugal distortion and interaction constants were derived from the fit together with the following band centers: ν0(ν2, 35Cl2CO) = 572.526299(30) cm-1, ν0(ν4, 35Cl2CO) = 582.089026(30) cm-1, ν0(ν2,35Cl37ClCO) = 568.951791 (35) cm-1 and ν0(ν4, 35Cl37ClCO) = 581.758279 (35) cm-1.
Molecular Physics


phosgene, high-resolution infrared spectrum, molecular constants


Lafferty, W. , Flaud, J. , Kwabia, F. , Perrin, A. , Manceron, L. and Ndao, M. (2017), First far-infrared high resolution analysis of the ν2 and ν4 bands of phosgene 35Cl2CO and 35Cl37ClCO, Molecular Physics, [online], (Accessed April 18, 2024)
Created October 27, 2017, Updated November 10, 2018