[Effect of further complexing on the spectral-luminescent properties of Mg-porphyrins].

It has been shown by investigations of polarization spectra and the dependence of the degree of fluorescence and phosphorescence polarization on emission wavelength that in non-polar solvents at 77 degrees K the molecules of Mg porphin and Mg tetraphenylporphin possess true symmetry D4h. When polar molecules (water, alcohols, pyridine) are present in the solution further complexing of the magnesium complexes with extra-ligands takes place and the polarization data indicate that D4h symmetry is absent which leads to splitting of the doubly degenerate states by 100-150 cm-1. It has been established that on further complexing the S1 and T1 levels are lowered by approximately 500 and 700 cm-1, respectively, the probability of intercombinational degradation T1 leads to S0 increases in this case. It follows from the data obtained that the extra-ligands do not essentially influence spin-orbit interaction.