Catalytic O[bond]O activation chemistry mediated by iron hangman porphyrins with a wide range of proton-donating abilities.
[reaction: see text] A library of hanging porphyrin xanthene (HPX) compounds containing pendant groups with various proton-donating abilities (pK(a) ranging from approximately 2 to 25) has been synthesized. Their corresponding chloroiron(III) complexes promote the catalase-like disproportionation of hydrogen peroxide. The overall activity and turnover numbers (TONs) are maximal for iron HPX complexes bearing acidic hydrogen-bond pendants. These results establish that careful control of intramolecular proton inventory can dramatically influence the catalytic activation of O-O bonds.
Chng
Leng Leng
LL
Department of Chemistry, 6-335, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139-4307, USA.
Chang
Christopher J
CJ
Nocera
Daniel G
DG
D002384:Catalysis; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D010100:Oxygen / Q000737:chemistry*; D011166:Porphyrins / Q000737:chemistry*; D011522:Protons
D011166:Porphyrins; D011522:Protons; D007501:Iron; D010100:Oxygen