CASPT2//CASSCF approach has been considered to explore the excited states PES landscape and hence characterize the photochemistry of these compounds around the isomerizable pathways. As a first step the ground state geometry has been optimized for all compounds at DFT level using the B3LYP functional. Subsequently, those geometries were used to compute the absorption spectrum as vertical excitations using CAM-B3LYP functional in the TD-DFT formalism. For this kind of systems, this functional feature a proper description as previously reported, even usually underestimates the π-π* transition in comparison with n-π*. The nature of the excited states has also been determined using NTO formalisms. For the computation of UV-Vis spectra, a Wigner distribution over the vibrational normal modes was done and 100 geometries were generated. The final spectrum was a convolution of gaussians of the single point computed transition energies using the CAM-B3LYP/6-31G*. On top of the B3LYP optimized geometry wavefunction calculations have also been performed under MS-CASPT2//SA(4)-CASSCF level of theory. Firstly, CASSCF calculations including 4 averaged states (from S0 to S3) were done followed by a multistate 2 nd order perturbation theory to the CASSCF wavefunction. As previously reported, the active space containing 10 electrons in 9 orbitals (10,9) was used for compound 4d, including the n orbital and different π and π* orbitals. In case of 6a and 6d the use of 8 electrons in 8 orbitals (8,8) was selected consistently with the elimination of the n orbital.