Synthesis and properties of a heterobimetallic iron-manganese complex and its comparison with homobimetallic analogues.

Graphical abstract Highlights • Heterometallic Fe-Mn complex synthesized and characterized. • The Fe-Mn complex reacts faster with oxygen higher than Fe-Fe and Mn-Mn complexes. • The CV of the Fe-Mn complex shows richer chemistry than Fe-Fe and Mn-Mn complexes. • Fe can replace Mn in the Mn-Mn complex to give Fe-Mn complex. Abstract Heterobimetallic cofactors containing one manganese and one iron ion have recently been found within the di-metal carboxylate protein family. Herein we report the synthesis and characterization of three binuclear metal complexes with Fe-Fe, Mn-Mn, and Fe-Mn metal composition. All three complexes use the same ligand framework, the BPMP ligand (HBPMP = 2,6-bis[(bis (-2-pyridylmethyl)amine) methyl]-4-methylphenol)) with two additional acetate ligands bridging the two metals. In terms of stability towards metal exchange, the Fe-Mn is more stable than the Mn-Mn complex but less stable than the Fe-Fe complex. Cyclic voltammetry shows that the Fe-Mn complex behaves markedly different than the homobimetallic complexes. The Fe-Mn complex also shows higher reactivity with O 2 than both the Fe-Fe and the Mn-Mn counterparts. [ABSTRACT FROM AUTHOR]