Spectroscopic and physicochemical properties of rare-earth phthalocyanines entrapped in sol-gel glasses

Abstract The electronic absorption spectra of samarium and neodymium phthalocyanines in DMSO and entrapped in glasses obtained via the sol-gel technique have been obtained. Decrease in concentration of metallophtalocyanines in DMSO leads to observed changes in the relative intensifies of the two bands in the Q-band region. This behavior could be explained by the shifts in equilibrium between the LnPc 2 and LnPc + forms, caused by the dilution. In view of this interpretation, the entrapment of the metallophthalocyanines in the sol-gel glass matrices shifts the diphthalocyanine ⇆ monophthalocyanine equilibrium towards the monophthalocyanine (LnPc + ) form.