ABSTRACT
The synthesis of dioxadiazuliporphyrinogen 7 and its oxidized forms: dioxadiazuliporphyrin 8 and dication 8(2+), is reported. These compounds were characterized in solution using UV-vis and 1H and 13C NMR spectroscopic means and in the solid state via single-crystal X-ray diffraction analysis. Dioxadiazuliporphyrin is a nonaromatic porphyrinoid, readily and reversibly oxidizable to its cation radical and to the aromatic carbaporphyrinoid dication, which can be viewed as a 21,23-dicarba-22,24-dioxaporphyrin with two fused tropylium rings. Further insight into the geometric and magnetic manifestations of aromaticity and antiaromaticity in the case of the redox couple 8, 8(2+) is obtained using density functional calculations and nucleus-independent chemical shifts.
Subject(s)
Infrared Rays , Porphyrins/chemical synthesis , Porphyrins/radiation effects , Crystallography, X-Ray , Magnetic Resonance Spectroscopy/methods , Magnetic Resonance Spectroscopy/standards , Models, Chemical , Models, Molecular , Molecular Structure , Oxidation-Reduction , Porphyrinogens/chemical synthesis , Porphyrinogens/chemistry , Porphyrinogens/radiation effects , Porphyrins/chemistry , Reference Standards , StereoisomerismABSTRACT
The porphyrias are a heterogeneous group of clinical disorders that share a common etiologic background in that each manifests a major metabolic defect in the synthesis of heme. The porphyrias represent an important category of human disease, perhaps as much for what they can teach us about how metabolic abnormalities are translated into clinical manifestations as they are as diseases per se. In this discussion an effort is made to describe, in some detail, the metabolic steps involved in the synthesis of heme and to correlate known abnormalities in this sequence of reactions that are associated with human porphyria.
