The enthalpies of solution of Fe(III) and Mn(III) complexes with porphyrins
of the chlorophyll group (chlorophyll ligand, pheophorbid, chlorin e(6)) a
nd protoporphyrin in various organic solvents at 298.15 K were determined c
alorimetrically. The influence of the structural features of porphyrin mole
cules and nature of the solvent on the enthalpy characteristics of porphyri
n-sol vent interaction was discussed.