DFT Study of Photochemical Properties and Radiative Forcing Efficiency Features of the Stereoisomers Cis- and Trans-CHCl=CH-CF3

The accurate assessment of radiative forcing efficiency (RFE) of a greenhouse gas is based on the precise knowledge of the structure and infrared absorption spectrum. This present work investigates the UV-vis absorption spectra and IR absorption spectra which fall into the determination of RFE of the short-lived compounds cis- and trans-CHCl=CHCF3 (CTFP). These investigations were carried out with six different DFT methods B3LYP, CAM-B3LYP, M06, M06-2X, TPSS0 and ωB97X-D associated to the basis set 6-31G(3df). Therefrom, the relative populations of the two states cis and trans for temperatures over the range 220 – 370 K at 1 atm and along the atmospheric altitude were assessed. It turns out that, trans-CTFP is the abundant component between the two states. This review reveals that, B3LYP and M06 reproduce well the experimental results of UV-vis spectra of trans-CTFP. As for cis-CTFP, EOM-CCSD is not well fitted by DFT methods. The cis- to trans-CTFP isomerisation leads to the red shift for DFT methods, an...