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Ligand modification transforms a catalase mimic into a water oxidation catalyst.

ABSTRACT: The catalytic reactivity of the high-spin Mn(II) pyridinophane complexes [(Py2NR2)Mn(H2O)2](2+) (R=H, Me, tBu) toward O2 formation is reported. With small macrocycle N-substituents (R=H, Me), the complexes catalytically disproportionate H2O2 in aqueous solution; with a bulky substituent (R=tBu), this catalytic reaction is shut down, but the complex becomes active for aqueous electrocatalytic H2O oxidation. Control experiments are in support of a homogeneous molecular catalyst and preliminary mechanistic studies suggest that the catalyst is mononuclear. This ligand-controlled switch in catalytic reactivity has implications for the design of new manganese-based water oxidation catalysts.

SUBMITTER: Lee WT

PROVIDER: S-EPMC4167389 | biostudies-literature | 2014 Sep

REPOSITORIES: biostudies-literature

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Ligand modification transforms a catalase mimic into a water oxidation catalyst.

Lee Wei-Tsung WT Muñoz Salvador B SB Dickie Diane A DA Smith Jeremy M JM

Angewandte Chemie (International ed. in English) 20140715 37

The catalytic reactivity of the high-spin Mn(II) pyridinophane complexes [(Py2NR2)Mn(H2O)2](2+) (R=H, Me, tBu) toward O2 formation is reported. With small macrocycle N-substituents (R=H, Me), the complexes catalytically disproportionate H2O2 in aqueous solution; with a bulky substituent (R=tBu), this catalytic reaction is shut down, but the complex becomes active for aqueous electrocatalytic H2O oxidation. Control experiments are in support of a homogeneous molecular catalyst and preliminary mec ...[more]

PMID: 25044487

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