Spin–orbit ab initio investigation of the photodissociation of CH2Cl2

The electronic excited states of dichloromethane in the 5.8-10.8 eV energy range investigated by experimental and theoretical methods

“…For the singlet excitations, the present results are in much better agreement with the experimental data. Furthermore they are higher in energy than the results from the calculations performed by Mandal et al [10], by 0.5 eV at the TD-PBE0 level, and with those of Xiao et al [39], at the CASPT2 level, possibly due to their [37] smaller basis set and/or active space used. The calculated lowest singlet transitions at the MS-CASPT2(20,14)/aug-cc-pV5Z(g) and the MS-CAS (20,14)+icMRCI+Q/aug-cc-pV5Z(g) levels, give best agreement with the experimental values.…”

“…These include bond lengths and geometry [7], ultraviolet photoabsorption [8][9][10][11][12][13][14] and photodissociation [15,16], photon and multiphoton ionisation [17][18][19], photoelectron spectroscopy [20,21], photo-oxidation [22,23] and electron impact spectroscopies [24][25][26][27][28][29][30][31][32][33][34], with the most recent electron scattering measurement reported by Hlousek et al [35] and the Madrid group [36] (and references therein), with a particular focus on elastic differential cross sections and its grand total cross section, respectively. We also note that dichloromethane has been explored by several theoretical methods with studies investigating its molecular orbitals and geometry [10,37,38], calculations on the vertical excitation energies of its neutral molecule [10] and photodissociation [39].…”

Direct photoisomerization of CH2I2vs. CHBr3 in the gas phase: a joint 50 fs experimental and multireference resonance-theoretical study

“…This is also the case for structurally related halogenated alkanes. [84][85][86][87][88] Herein, we find that the picture painted by the previous works based on scanning a single coordinate at a time naturally misses out on the multidimensional character of the photochemical transformation described herein. Furthermore, the computed CIs are situated at much lower energy than the FC point, and therefore, are energetically accessible 'funnels' for non-adiabatic photoisomerization of the excited parent molecules.…”