On aggregation of carboxyl-containing phthalocyanine

Analysis of aggregation of ionic carboxyl-containing 2,3,9,10,16,17,23,24-octa[(3,5-biscarboxy)phenoxy]phthalocyanine (C88H42N8Na8O24) molecules in water was carried out using the methods of electronic and emission spectroscopy. In the UV spectra, a shift of the absorption maxima to longer wave-lengths with increasing pththalocyanine concentration was observed. The most intense absorption maximum appears at 627 nm. The luminescence spectra of aqueous solutions of phthalocyanine in the range of 350–600 nm with excitation wavelength of 300–350 nm were recorded. Growth of the luminescence maximum intensity with an increasing excitation band was observed. It was found that the phthalocyanine concentration affects the luminescence intensity, which manifested itself in its growth at low concentrations and a decrease in the concentration range of 0.08–1.5 μM with a shift of the maximum to shorter wavelengths. Comparison of the spectra of phthalocyanines of different functionality in the presence of sodium hydroxide was performed. Microimages of phthalocyanine aggregates in the polymer films were obtained using reflected optical microscopy. The structure of phthalocyanine nanoaggregates formed in water and on the mica surface was studied by atomic force microscopy (AFM) and Raman spectroscopy.