Spectrophotometric Studies of the Thermodynamics of Molecular Interaction between Some Free Base meso-Tetraarylporphyrins and SbF3

Abstract

Spectrophotometric study was applied to the interaction of SbF3 with para-, meta-, and ortho-substituted meso-tetraarylporphyrins (H2t(Xp)p; X: H, OCH3, CH3, and Cl) in CHCl3. The 1:1 formation constants of the resulting complexes were calculated at several temperatures by the computer fitting of absorbances of solutions versus mole ratio data with appropriate equations. Thermodynamic parameters (G0, H0, and S0) have been determined and the influence of electron donation and steric effect of the substituted aryl groups in the free base porphyrins on the stability of the complexes is discussed.