Synthesis and Characterization of the “Pocket” Porphyrins

The synthesis of the “pocket” series is described. The iron(II) complexes have been extensively characterized by ¹H NMR, MCD, Mössbauer, direct axial ligand titrations, and magnetic susceptibility determinations. The results of these experiments indicate that in toluene, regimes of axial base concentration can be found in which iron(II) derivatives of the “pocket” porphyrins remain predominantly five-coordinate in the absence of gaseous ligand. Further, these five-coordinate complexes form stable and reversible oxygen adducts. The resonance Raman spectra of five-coordinate iron(II) “pocket” porphyrins are discussed as well as studies based on interactions with CO.