Iron and Porphyrin Metal–Organic Frameworks: Insight into Structural Diversity, Stability, and Porosity

Reaction
of iron­(IIII)­chloride with the free base tetrakis­(4-carboxyphenyl)­porphyrin
(H2TCPP) in the presence of different bases leads to the
formation of a series of iron/porphyrin metal–organic frameworks.
Such a crystal engineering approach led to the obtaining of four structures
presenting three different topologies and inorganic secondary building
units. Depending on the synthesis conditions, isolated FeIII octahedra, diiron­(II) paddle wheel dimers, or extended [FeIII(OH)­O4]n chains could be obtained
in a controlled manner. The influence of the synthetic conditions
on the final structure and the oxidation state of iron is discussed.
Stability of the porous solids towards air and water is studied, and
their intrinsic porosity is assessed.