N4 -metallomacrocyclic catalysts

From Model Structures to Active N4-Metallomacrocyclic Catalysts... 

Masa J, Ozoemena K, Schuhmann ZJH (2012) Oxygen reduction reaction using N4-metallomacrocyclic catalysts fundamentals on rational catalyst design. J Porphyrins Phthalocyanines 16(7) 761... 

The stability of metalloporphyrins and metallophthalocyanines alike is far from satisfactory for any practical application. Whereas there is irrefutable evidence for improved activity upon heat treatment of the N4-metallomacrocyclic complexes, the loss of their structural merit is obvious. The fact that the performance of nonprecious metal catalysts synthesized by heat treatment of inexpensive nitrogen, carbon, and metal precursors rivals that of heat-treated N4-metallomacrocyclic complexes, which... 

The development of N4 metallomacrocyclic compounds was inspired by biological catalysts such as cytochrome c and hemoglobin, and has received considerable attention in the last three decades. The attraction of these complexes is due to their lower costs, compared to nohle metals, and the ability to modulate their catalytic activity by changing the stmcture of the macrocyclic ligand. Figure 2 illustrates typical N4 macrocyclic stractures. 

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