First far-infrared high-resolution analysis of the nu(2) and nu(4) bands of phosgene (Cl2CO)-Cl-35 and (ClClCO)-Cl-35-Cl-37

摘要

A Fourier transform spectrum of phosgene (Cl2CO) has been recorded in the 17.3-mu m 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 nu(2) and nu(4) vibrational bands of the two isotopologues (Cl2CO)-Cl-35 and (ClClCO)-Cl-35-Cl-37. 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 2(1) and 4(1) vibrational states. In this way, it was possible to reproduce the upper-state rovibrational levels to within the experimental uncertainty, i.e. similar to 0.30 x 10(-3) cm(-1). Very accurate rotational and centrifugal distortion and interaction constants were derived from the fit, together with the following band centres: nu(0)(nu(2), (Cl2CO)-Cl-35) = 572.526299(30) cm(-1), nu(0)(nu(4), (Cl2CO)-Cl-35) = 582.089026(30) cm(-1), nu(0)(nu(2), (ClClCO)-Cl-35-Cl-37) = 568.951791(35) cm(-1) and nu(0)(nu(4), (ClClCO)-Cl-35-Cl-37) = 581.758279(35) cm(-1).