Water oxidation catalyzed by two cobalt complexes: new challenges and questions

Najafpour, Mohammad Mahdi; Feizi, Hadi

doi:10.1039/c7cy02602a

Cited by 45 publications

(29 citation statements)

References 61 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1, Mn, Co and Ni complexes (Fig. S1) were slowly decomposed under water-oxidation reaction, and as previously reported, the corresponded metal oxides were formed 17–19 . Such decomposition can significantly degrade the complex (Fig.…”

Section: Resultssupporting

confidence: 83%

A new decomposition mechanism for metal complexes under water-oxidation conditions

Najafpour

Feizi

2019

Sci Rep

Self Cite

View full text Add to dashboard Cite

Herein, water-oxidation reaction by cobalt(II) phthalocyanine, N,N′-bis (salicylidene) ethylenediamino cobalt(II), nickel(II) Schiff base (N,N′-bis (salicylidene)ethylenediamino nickel(II), nickel(II)) phthalocyanine-tetrasulfonate tetrasodium, manganese(II) phthalocyanine, 5,10,15,20-Tetraphenyl-21H,23H-porphine manganese(III) chloride, manganese(III) 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphine chloride tetrakis(methochloride) was investigated using electrochemistry, UV-vis spectroscopy and spectroelectrochemistry. According to our results, a new decomposition pathway for these metal complexes under water-oxidation conditions was proposed. The produced metal oxide obtained by decomposition of metal complex under water -oxidation conditions not only catalyzes water-oxidation reaction but this metal oxide also accelerates decomposition of the corresponding complex to form higher amounts of the metal oxide. We hypothesize that such a mechanism could be investigated for many metal complexes under different oxidation or reduction reactions.

show abstract

Section: Resultssupporting

confidence: 83%

A new decomposition mechanism for metal complexes under water-oxidation conditions

Najafpour

Feizi

2019

Sci Rep

Self Cite

View full text Add to dashboard Cite

show abstract

“…The latter is favored at extreme pH values. [13][14][15][16][17] This can foster the subsequent formation of metal oxides that can be responsible for the observed water oxidation catalysis. Therefore, deeper understanding of all these processes is essential to establish the real catalytic species that operate in a particular system and thus to obtain meaningful information for the design of more stable and active molecular catalyst.…”

Section: Introductionmentioning

confidence: 99%

Can Ni Complexes Behave as Molecular Water Oxidation Catalysts?

et al. 2019

View full text Add to dashboard Cite

The present report uncovers the borderline between homogeneous and heterogeneous water oxidation catalysis using a family of Ni complexes containing oxamidate anionic type of ligands. In particular, the Ni complex [(L 1)Ni II ] 2-(1 2-; L 1 = o-phenylenebis(oxamidate)) and its modified analogues [(L 2)Ni II ] 2-(2 2-;L 2 = 4,5-dimethyl-1,2-phenylenebis(oxamidate)) and [(L 3)Ni II ] 2-(3 2-;L 2 = 4methoxy-1,2-phenylenebis(oxamidate)) have been prepared and evaluated as molecular water oxidation catalysts at basic pH. Their redox features have been analyzed by mean of electrochemical measurements revealing a crucial involvement of the ligand in the electron transfer processes. Moreover, the stability of those complexes has been assessed both in solution and immobilized on graphene-based electrodes at different potentials and pHs. The degradation of the molecular species generates a NiOx layer, whose stability and activity as water oxidation catalyst has also been stablished. Electrochemical methods, together with surface characterization techniques, have shown the complex mechanistic scenario in water oxidation catalyzed by this family of Ni complexes, which consists of the coexistence of two catalytic mechanism: a homogeneous pathway driven by the molecular complex and a heterogeneous pathway based on NiOx. The electronic perturbations exerted through the ligand framework has manifested a strong influence over the stability of the molecular species under turnover conditions. Finally, 1 2has been used as a molecular precursor for the formation of NiFeOx anodes that behave as extremely powerful water oxidation anodes.

show abstract

“…In 2018, Najafpour and coworkers reported Co II (phthalocyanine) (115) and Co II (salen) (116). These complexes were screened for electrochemical catalytic water oxidation, and it was found that 116 was active at pH 11, whereas no dioxygen was observed for complex 115 [186]. High resolution visible spectra showed peaks at 410-430 nm and 680-740 nm that are characteristic of nanoparticles, which is indicative of the nanoparticulate nature of the real catalyst.…”

Section: −O]mentioning

confidence: 99%

Bio-Inspired Molecular Catalysts for Water Oxidation

et al. 2021

View full text Add to dashboard Cite

The catalytic tetranuclear manganese-calcium-oxo cluster in the photosynthetic reaction center, photosystem II, provides an excellent blueprint for light-driven water oxidation in nature. The water oxidation reaction has attracted intense interest due to its potential as a renewable, clean, and environmentally benign source of energy production. Inspired by the oxygen-evolving complex of photosystem II, a large of number of highly innovative synthetic bio-inspired molecular catalysts are being developed that incorporate relatively cheap and abundant metals such as Mn, Fe, Co, Ni, and Cu, as well as Ru and Ir, in their design. In this review, we briefly discuss the historic milestones that have been achieved in the development of transition metal catalysts and focus on a detailed description of recent progress in the field.

show abstract

Water oxidation catalyzed by two cobalt complexes: new challenges and questions

Abstract: Herein, two cobalt complexes as true catalysts for water oxidation were investigated.

Cited by 45 publications

References 61 publications

A new decomposition mechanism for metal complexes under water-oxidation conditions

A new decomposition mechanism for metal complexes under water-oxidation conditions

Can Ni Complexes Behave as Molecular Water Oxidation Catalysts?

Bio-Inspired Molecular Catalysts for Water Oxidation

Contact Info

Product

Resources

About