Single Excited Molecular Orbitals’ Contribution in Uv-Vis Absorption of Dichloride-bis(5,7- dichloroquinolin-8-olato)tin(IV): A Recent Study

Using first-principles approaches, the absorption spectrum of dichloride-bis(5,7-dichloroquinolin-8-olato)tin(IV) with the molecular formula Q2SnCl2 is calculated and compared with experimental data.
The single excited molecular orbitals (SEMO) from the ground state to the excited states of the molecule are used to calculate the energy correction terms for the excitation energies. The contributions of the Columbic interaction between an excited electron and the remaining hole in the absorption spectrum during the optical excitation process can be determined using this method. The density functional theory (DFT) is used to compute the MO energy difference and MO wave functions, as well as the SEMO energy contribution. The results show that using the SEMO's contributions in energy corrections improves the theoretical optical absorption spectrum greatly. The calculations are based on DFT, and the essential parameters and integrals for SEMO computation are acquired using this method. Due to its ability to describe MOs for any excitation energy and lower computational cost, this method is chosen over alternative ab-initio methods for calculating excited states. For the first time, the method is used to calculate the energy of transitions and specifies the electronic transition between MOs, particularly in absorption machinery of the OLED. The theoretical spectrum is closer to the experimental spectrum when the electron-hole interaction is taken into account in the optical mechanism of absorption in the molecule. As a result, the electron-hole interaction, or the interaction between the excited electron and the remaining hole, plays a critical role in the absorption mechanism that cannot be ignored.