Temperature-dependence of the UV cross section of dichlorine peroxide in the tail region of the 244 nm signal

We present a physical model that explains the dependence of the UV cross section of ClOOCl on temperature in the actinic wavelength region measured before by J.J. Lin, A.F. Chen and Y.T. Lee [Chemistry - An Asian Journal, 6, 1664-1678 (2011)]. It was unclear why there are frequency regions in which the cross section decreases with increasing temperature and others in which it increases. This interesting behaviour is now shown to be due to the non-rigidity of the molecule and can be described in terms of the Boltzmann populations of the lowest torsional states and small, non-systematic variations in their absorption cross sections. Combination of these two ingredients produces the non-trivial temperature effect.

Automated summary

The study presents a physical model to explain the dependence of UV cross section of ClOOCl on temperature in different frequency regions. This interesting behavior is attributed to the non-rigidity of the molecule and small, non-systematic variations in the absorption cross sections. The combination of these factors produces the non-trivial temperature effect observed.