TY - JOUR
T1 - Why is cobalt the best transition metal in transition-metal hangman corroles for O-O bond formation during water oxidation?
AU - Lai, Wenzhen
AU - Cao, Rui
AU - Dong, Geng
AU - Shaik, Sason
AU - Yao, Jiannian
AU - Chen, Hui
PY - 2012/9/6
Y1 - 2012/9/6
N2 - O-O bond formation catalyzed by a variety of β-octafluoro hangman corrole metal complexes was investigated using density functional theory methods. Five transition metal elements, Co, Fe, Mn, Ru, and Ir, that are known to lead to water oxidation were examined. Our calculations clearly show that the formal Co V catalyst has a Co IV-corrole •+ character and is the most efficient water oxidant among all eight transition-metal complexes. The O-O bond formation barriers were found to change in the following order: Co(V) ≪ Fe(V) < Mn(V) < Ir(V) < Co(IV) < Ru(V) < Ir(IV) < Mn(IV). The efficiency of water oxidation is discussed by analysis of the O-O bond formation step. Thus, the global trend is determined by the ability of the ligand d-block to accept two electrons from the nascent OH -, as well as by the OH • affinity of the TM(IV)=O species of the corresponding TM(V)=O·H 2O complex. Exchange-enhanced reactivity (EER) is responsible for the high catalytic activity of the Co(V) species in its S = 1 state.
AB - O-O bond formation catalyzed by a variety of β-octafluoro hangman corrole metal complexes was investigated using density functional theory methods. Five transition metal elements, Co, Fe, Mn, Ru, and Ir, that are known to lead to water oxidation were examined. Our calculations clearly show that the formal Co V catalyst has a Co IV-corrole •+ character and is the most efficient water oxidant among all eight transition-metal complexes. The O-O bond formation barriers were found to change in the following order: Co(V) ≪ Fe(V) < Mn(V) < Ir(V) < Co(IV) < Ru(V) < Ir(IV) < Mn(IV). The efficiency of water oxidation is discussed by analysis of the O-O bond formation step. Thus, the global trend is determined by the ability of the ligand d-block to accept two electrons from the nascent OH -, as well as by the OH • affinity of the TM(IV)=O species of the corresponding TM(V)=O·H 2O complex. Exchange-enhanced reactivity (EER) is responsible for the high catalytic activity of the Co(V) species in its S = 1 state.
UR - http://www.scopus.com/inward/record.url?scp=84865966651&partnerID=8YFLogxK
U2 - 10.1021/jz3008535
DO - 10.1021/jz3008535
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AN - SCOPUS:84865966651
SN - 1948-7185
VL - 3
SP - 2315
EP - 2319
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
IS - 17
ER -