Spectroscopic characterization of the water-soluble cationic porphyrins and their complexes with Cu(II) in various solvents

The spectroscopic properties of two cationic porphyrins with different residues in a periphery of the porphyrin plane (H2TMePyP and H2TTMePP) and their Cu(II) complexes were studied in water and organic solvents (MeOH, EtOH, DMSO and DMF). The wavelengths of the absorbance and fluorescence band maxima were correlated with the polarity of the solvents. The linear dependence of the spectral band blue shift from Reichardt's polarity parameter is described. The relative quenching of the Q band in more polar solvents is shown. These effects are particularly strong for the porphyrins with spatial peripheral positively charged groups. (C) 2002 Elsevier Science B V All rights reserved.