Solvent effects on the absorption and fluorescence characteristics of tin(IV) mesoporphyrin

The absorption and fluorescence characteristics of tin(IV) mesoporphyrin (SnMP) and its analog tin(IV) protoporphyrin (SnPP) were studied in a series of organic solvents. Fluorescence quantum yields were calculated using the Strickler-Berg equation. Good correlation was found between calculated values and measured relative values. Fluorescence lifetime, radiative lifetime and non-radiative lifetime were also calculated. The parameters showed variation depending on ligation as well as H-bonding. Unusual long lifetime and high quantum yields were found in alcohol solvents. This finding might contribute to elucidation of the nature of tin porphyrins to inhibit heme oxygenase.