Photochemistry of tetrasulphonated magnesium phthalocyanine in water and DMSO solutions by Raman, femtosecond transient absorption, and stationary absorption spectroscopies

Abstract Photochemical and photophysical behavior of the tetrasulphonated magnesium phthalocyanine MgPcS 4 has been studied by Raman spectroscopy, femtosecond transient absorption, and stationary UV–VIS absorption spectroscopies. It has been shown also that the dimerization equilibrium constant K for the tetrasulfonated magnesium phthalocyanine is strongly shifted towards monomeric form in DMSO solutions compared to aqueous systems. The Raman and emission spectra recorded in the range of 294–77 K combined with the femtosecond transient absorption reveal spectral features that provide unique information about the primary photochemical and photophysical events of magnesium phthalocyanines in liquid solutions as well as in the crystal frozen matrices.