Resonance Raman and electrocatalytic behavior of thiolate and imidazole bound iron porphyrin complexes on self assembled monolayers: functional modeling of cytochrome P450.
Electrodes bearing thiolate and imidazole coordinated iron porphyrin catalysts are constructed and characterized using resonance Raman spectroscopy, absorption spectroscopy, and electrochemistry. The cyclic voltammetry data and their pH dependences are used to establish the nature of the exchangeable trans ligands in both of these cases. In situ monitoring of partially reduced oxygen species (PROS) produced during O(2) reduction using rotating ring disc electrochemistry (RRDE) experiments provide direct insight into the "push-effect" of the thiolate ligand. The thiolate bound iron porphyrin electrode generates highly oxidizing species on the electrode during electrocatalytic O(2) reductions which are very reactive. These surfaces can utilize these oxidants to catalytically hydroxylate strong C-H bonds using molecular O(2) with turnover numbers as high as 200.
Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata, India 700032.
Kushal
K
Sengupta
Sudipta
S
Chatterjee
Subhra
S
Samanta
Sabyasachi
S
Bandyopadhyay
Abhishek
A
Dey
D002384:Catalysis; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry* / Q000378:metabolism; D055664:Electrochemical Techniques; D004566:Electrodes; D005290:Ferric Compounds / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007093:Imidazoles / Q000737:chemistry*; D008665:Metalloporphyrins / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D013059:Spectrum Analysis, Raman; D013438:Sulfhydryl Compounds / Q000737:chemistry*
D005290:Ferric Compounds; D007093:Imidazoles; D008665:Metalloporphyrins; D013438:Sulfhydryl Compounds; C029899:imidazole; D003577:Cytochrome P-450 Enzyme System; D010100:Oxygen