Four Metalloporphyrinic Frameworks as Heterogeneous Catalysts for Selective Oxidation and Aldol Reaction

Four porous metalloporphyrinic framework
materials, [(CH3)2NH2]­[Zn2(HCOO)2(MnIII–TCPP)]·5DMF·2H2O (1; H6TCPP = tetrakis­(4-carboxyphenyl)­porphyrin),
[(CH3)2NH2]­[Cd2(HCOO)2(MnIII–TCPP)]·5DMF·3H2O (2), [Zn2(HCOO)­(FeIII(H2O)–TCPP)]·3DMF·H2O (3), and [Cd3(H2O)6(μ2-O)­(FeIII–HTCPP)2]·5DMF (4) were synthesized by heating a mixture of MIIICl–H4TCPP (M = Mn and Fe) and M′ (M′
= Zn or Cd) nitrate in a mixed solvent of DMF and acetic acid. Compounds 1–3 are built up from M′2(COO)4 paddle-wheel subunits bridged by MIII–TCPP and formate ligands to form their 3D connections. The
formate pillar heterogeneously connects with M and M′ cations
in 1 and 2 and homogeneously joins M′
cations in 3. The μ2-O bridged FeIII–HTCPP dimer performs as a decadentate ligand to
link 10 cadmium cations for the formation of an interesting 3D coordination
network of 4. The four porphyrinic frameworks present
interesting catalytic properties in the selective epoxidation of olefins,
oxidation of cyclohexane, and intermolecular aldol reaction of aldehydes
and ketones.