Influence of Isomerism of the Ligand on the Enthalpies of Formation of Copper Tetrapyridylporphine

摘要

The enthalpy of dissolution of the tetrapyridylporphine isomers in water and in aqueous solutions of magnesium and copper acetates at a constant salt concentration (~7 mmol/1) were observed for the first time by the calorimetric method with spectrophotometric monitoring. A substantial influence of the electronic effects of the tetrapyridyl fragment with different (para, meta, and ortho) positions of the heteroatom on the enthalpies of coordination of the ligands by the Cu~(2+) ions was revealed.