Functional Analogues of Cytochrome c Oxidase, Myoglobin, and Hemoglobin

Abstract

Contents 1. Introduction 561 2. Biomimetic Analogues of Hemoglobin and Myoglobin 563 2.1. The Proteins 563 2.2. Synthetic Analogues of Mb 565 2.2.1. The Molecular Origin of CO vs O 2 Discrimination by Mb and Hb 565 2.2.2. Electrostatic and H-Bonding Effects on Heme's Affinity for Small Molecules 570 2.2.3. Reversible Oxygen Carriers in Protic Media 572 2.3. Reversible Cooperative O 2 Carriers: Biomimetic Analogues of Hb 573 3. Functional Analogues of the Heme/Cu B Site of Cytochrome c Oxidase 574 3.1. The Enzyme 574 3.2. Methodology of Electrocatalytic Studies of Heme/Cu Analogues 576 3.3. General Considerations for the Design of Biomimetic Heme/Cu Analogues for Electrocatalytic Studies 577 3.4. Electrocatalytic O 2 Reduction by Simple Fe Porphyrins 578 3.5. Biomimetic Electrocatalytic Studies Prior to 2000 582 3.6. Role(s) of Cu B Based on Biomimetic Electrocatalytic Studies 583 4. Conclusions 585 5. Acknowledgments 586 6. Supporting Information Available 586 7. References 586

Nuclearity and cooperativity effects in binuclear catalysts and cocatalysts for olefin polymerization

“…The sequence of first introducing Zr(NMe 2 ) 2 then Ti(NMe 2 ) 2 is used because the former ligand substitution process is far more rapid and more selective. For control experiments, monometallic CGC complexes Zr 1 and Ti 1 were synthesized via methodologies similar to those for the bimetallic complexes (14,17) (Fig. 20, which is published as supporting information on the PNAS web site).…”

“…catalysis ͉ polymer ͉ polyolefin E nzymes achieve superior reactivity and selectivity, in part, by their efficacy in creating high local reagent concentrations and special, conformationally advantageous active site-substrate proximities and interactions (1)(2)(3)(4). In this regard, the possibility of unique and more efficient abiotic catalytic transformations based on cooperative effects between adjacent active centers in multinuclear transition metal complexes is currently of great interest.…”

Chemical Fixation of CO2 and Other Heterogeneous Catalytic Studies by Employing a Layered Cu‐Porphyrin Prepared Through Single‐Crystal to Single‐Crystal Exchange of a Zn Analogue

“…The foremost metalloporphyrin is Fe-porphyrin,w hich is an important cofactori n oxygen transport. [8] Many metalloporphyrins have also been explored for catalysis. [9] The versatility and the rigidity of metalloporphyrins is attractive in the construction of new MOFs.…”

Electrochemical evidence of catalysis of oxygen reduction at the polarized liquid–liquid interface by tetraphenylporphyrin monoacid and diacid

“…bimetallic, heme/Cu catalytic site in cytochrome c oxidase [1,2]. Their synthetic analogues have been used to activate molecular oxygen for the O 2 reduction to hydrogen peroxide (H 2 O 2 ) and/or to water in the solution [3], at the solid electrodes [4], or at the polarized liquid-liquid interfaces [5,6].…”

“…Their synthetic analogues have been used to activate molecular oxygen for the O 2 reduction to hydrogen peroxide (H 2 O 2 ) and/or to water in the solution [3], at the solid electrodes [4], or at the polarized liquid-liquid interfaces [5,6]. The activation process involves the binding of O 2 to the metal center, and the electron delocalization from the metal to O 2 , which can be viewed like a coordinated superoxide or peroxide anion, i.e., as a Brønsted base [1,2]. To the best of our knowledge, the catalysis of O 2 reduction by a metal-free porphyrin has not been reported yet.…”