Spectroscopic and theoretical study of novel copper(II) complexes based on phenothiazine ligands: UV-Visible absorption and photoinduced electron transfer

This study presents three novel copper (II) complexes based on phenothiazine ligands that were synthesized and revealed their structures by spectral and analytical measurements. The synthesized complexes offered potential opportunities to explore their UV-visible absorption properties and photoinduced electron transfer with triethylamine. We performed density functional theory (DFT) calculations for Cu(II) (HL1)2 compounds and studied their frontier molecular orbitals in different environments. The calculations were done by using PBE1PBE functional and 6-31G(d)/Lanl2dz basis sets. We applied the LANL2DZ basis set for Cu. The treatment of all the other atoms was done by a 6-31G(d) basis set. For the calculation of the electronic structure, the basis set 6-31 + G(d)/Lanl2dz and SMD solvation model with MeCN and DMF were employed. We computed the frequencies to confirm the stability of the structures. Theoretical calculations can help explain the experimental findings, provide insights into the electronic transitions responsible for UV-visible absorption, and elucidate the photo -induced electron transfer processes involved.