Synthesis, solid state molecular structures, and cyclic voltammetry of five-coordinate perchlorate manganese porphyrins and a benzamide derivative

We report the synthesis and characterization of two perchlorate manganese porphyrins obtained from the reactions of tetra-phenyl based porphyrin manganese chloride precursors, (T(p-Cl)PP)MnCl (T(p-Cl)PP = 5,10,15,20-tetra-p-chlorophenylporphyrinato dianion) and (TPP)MnCl (TPP = 5,10,15,20-tetraphenylporphyrinato dianion), with excess silver perchlorate. A further reaction between (TPP)Mn(OClO₃) and benzamide was performed, resulting in the formation of a six-coordinate benzamide derivative, (TPP)Mn(O=C(NH₂)Ph)(OClO₃). The complexes were characterized by UV-Vis and IR spectroscopy, as well as single-crystal X-ray crystallography. The molecular structures of (T(p-Cl)PP)Mn(OClO₃) and (TPP)Mn(O=C(NH₂)Ph)(OClO₃) reveal monodentate O-binding of the perchlorate and benzamide to the manganese center. The intermolecular interactions within the crystalline packing of both complexes were investigated using Hirshfeld surface analysis. In addition, the redox behavior of (T(p-Cl)PP)Mn(OClO₃) was studied through cyclic voltammetry in THF.