Investigation of photochromic transformations of diarylethenes using spectrophotometry and quantum chemistry

An analysis of the results of complex experimental and theoretical studies of photoinduced changes in the electronic spectra of photochromic diarylethenes (DAE) of various structures is presented. The electronic absorption spectra of DAE and the molecular orbitals involved in the formation of these spectra are calculated. The results of quantum chemical calculations are consistent with the experimental spectrophotometric data of the DAE. An analysis of the boundary molecular orbitals of the studied DAEs was carried out and, on its basis, their electronic properties were determined and analyzed. Features (in comparison with other considered DAE molecules) of the electronic structure of the DAE2 molecule (containing fluorine atoms) were revealed, which are also manifested in the calculated electronic parameters. The results obtained can be used to optimize the choice or targeted synthesis of photochromic diarylethenes (with required properties) used in various nanostructured systems for molecular electronics and photonics devices.