Effect of molecular structural elements of chloro-substituted derivatives of naphthalene on intramolecular interactions, which determine T 1 ↝ S 0 nonradiative transition

By calculating the matrix elements of operators of adiabatic and nonadiabatic interactions, which determine the process T 1 S ↝ S 0 in molecules of naphthalene and its 1,4- and 2,3-dichloro-substituted derivatives, we study how various factors of intramolecular interactions affect this process. The effects of α and β chlorine substituents on spin-orbit (SO) interactions in the carbon backbone of the molecule and in its chlorine atoms, where the compensation effect of SO interactions was revealed, are separated. It is found that high-frequency out-of-plane promoting modes (corresponding to vibrations of CCH groups) differently affect SO interactions in the carbon backbone of molecules and in chlorine atoms.