Synthesis, crystal structures and catalytic abilities of new macrocyclic bis-pyridineamido MnIII and FeIII complexes

A new macrocyclic ligand H2L (H2L = 1,2-[bis(6′-pyridine-2′-carboxamido)-ethane]benzene) has been designed and synthesized by condensation of pyridine-carboxylic acid and diamine. Its Mn(III) and Fe(III) complexes, [Mn(L)Cl (DMF)] and [Fe(L)Cl], were prepared and respectively characterized by IR, UV–Vis, ESI-Mass, elemental analysis and X-ray single crystal diffraction. The catalytic abilities of them were examined, and up to 95% yield was achieved in epoxidation of styrene. The preliminary investigation of catalytic mechanism by manganese complex was carried out, suggesting the involvement of Mn(V) oxo species during catalysis.

Graphical abstractThe new macrocyclic bis-pyridine amide Fe(III) and Mn(III) complexes have been synthesized, structurally determined and their applications in epoxidation have been studied with the best yield of 95% for styrene. The mechanism studies suggested the involvement of Mn(V)O species during catalysis.Figure optionsDownload full-size imageDownload as PowerPoint slide