Single Electron Transfer Steps in Water Oxidation Catalysis. Redefining the Mechanistic Scenario

Abstract

The systematic computational study of the mechanism for water oxidation in four different complexes confirms the existence of an alternative mechanism to those previously

Quantum Chemical Study of the Mechanism of Water Oxidation Catalyzed by a Heterotrinuclear Ru2Mn Complex

“…[54] The experimental solvation free energies of water (À6.3 kcal mol À1 ) [54] and acetate (À77.0 kcal mol À1 ) [55,56] in aqueous solution were used. [16,[59][60][61][62][63][64][65] Results and Discussion [57] Importantly,t he use of either the experimental values or the calculated values did not alter any mechanistic conclusions.…”

Electrochemical Water Oxidation and Stereoselective Oxygen Atom Transfer Mediated by a Copper Complex

“…Four-electron water oxidation to form dioxygen (2 H 2 O!O 2 + 4H + + 4e À )i st here-fore attracting much attention.I nn ature,w ater oxidation is performed during photosynthesis by the Mn 4 Ca metallicc ofactor of the oxygen evolvingc enter( OEC) of plant photo-systemII( PSII). [4,5,[9][10][11] In the first one (Scheme 1A), water nucleophilic attack (WNA) on ah igh-valent metal-oxo species results in ah ydroperoxo intermediate, which can be furthero xidized to release O 2 .I nt he second one, two high-valent metal-oxo speciesc ouple to form the OÀO bond.T his can occur eitherf rom terminal M n + 2 =Os pecies (I2M) or from bridging oxo groups (m-O) between two metal centers (RI;S cheme 1B). [4][5][6][7][8] The development of these bioinspired molecular complexes has greatly contributed to ab etter understanding of the mechanisms and intermediates involved in water oxidation catalysis; this is crucial knowledge for the development of new generations of efficient and stable catalysts.…”

Quantum Chemical Modeling of Homogeneous Water Oxidation Catalysis

“…[63] ChemSusChem 2017, 10,4236 -4263 www.chemsuschem.org . [77,78] If electrondonating OMe groups are introduced into the phenyl ring, the overpotential can be decreased to 0.27 Vw ith one OMeg roup and 0.17 Vw ith two OMe groups.H owever, the TOF also decreasesb ya no rder of magnitude and decomposition of the ligand is observed. Density functional calculations were used to explore the reaction mechanism and constructafull catalytic cycle.…”