Tuning the MnII2/MnIII2 redox cycle of a phenoxo-bridged diMn catalase mimic with terminal carboxylate donors. Solís, V., Palopoli, C., Daier, V., Rivière, E., Collin, F., Moreno, D. M., Hureau, C., & Signorella, S. Journal of Inorganic Biochemistry, 182:29–36, 2018.
Tuning the MnII2/MnIII2 redox cycle of a phenoxo-bridged diMn catalase mimic with terminal carboxylate donors [link]Paper  doi  abstract   bibtex   
A new phenoxo-bridged diMnIII complex, Na[Mn2L(OH)2(H2O)2]·5H2O (1), obtained with the ligand L5− = 5‑methyl‑2‑hydroxo‑1,3‑xylene‑α,α‑diamine‑N,N,N′,N′‑tetraacetato, has been prepared and characterized. Mass spectrometry, conductivity, UV–visible, EPR and 1H NMR spectroscopic studies showed that the complex exists in solution as a monoanionic diMnIII complex. Complex 1 catalyzes H2O2 disproportionation with second-order rate constant kcat = 305(9) M−1 min−1 and without a time-lag phase. Based on spectroscopic results, the catalase activity of complex 1 in methanol involves a MnIII2/MnII2 redox cycle, which distinguishes this catalyst from other phenoxo-bridged diMn complexes that cycle between MnIIMnIII/MnIIIMnIV species. Addition of base stabilizes the catalyst, restrains demetallation during catalysis and causes moderate enhancement of catalase activity. The terminal carboxylate donors of 1 not only contribute as internal bases to assist deprotonation of H2O2 but also favor the formation of active homovalent diMn species, just as observed for the enzyme.
@article{solis_tuning_2018,
	title = {Tuning the {MnII2}/{MnIII2} redox cycle of a phenoxo-bridged {diMn} catalase mimic with terminal carboxylate donors},
	volume = {182},
	issn = {0162-0134},
	url = {https://www.sciencedirect.com/science/article/pii/S0162013417307389},
	doi = {10.1016/j.jinorgbio.2018.01.013},
	abstract = {A new phenoxo-bridged diMnIII complex, Na[Mn2L(OH)2(H2O)2]·5H2O (1), obtained with the ligand L5− = 5‑methyl‑2‑hydroxo‑1,3‑xylene‑α,α‑diamine‑N,N,N′,N′‑tetraacetato, has been prepared and characterized. Mass spectrometry, conductivity, UV–visible, EPR and 1H NMR spectroscopic studies showed that the complex exists in solution as a monoanionic diMnIII complex. Complex 1 catalyzes H2O2 disproportionation with second-order rate constant kcat = 305(9) M−1 min−1 and without a time-lag phase. Based on spectroscopic results, the catalase activity of complex 1 in methanol involves a MnIII2/MnII2 redox cycle, which distinguishes this catalyst from other phenoxo-bridged diMn complexes that cycle between MnIIMnIII/MnIIIMnIV species. Addition of base stabilizes the catalyst, restrains demetallation during catalysis and causes moderate enhancement of catalase activity. The terminal carboxylate donors of 1 not only contribute as internal bases to assist deprotonation of H2O2 but also favor the formation of active homovalent diMn species, just as observed for the enzyme.},
	language = {en},
	urldate = {2022-02-01},
	journal = {Journal of Inorganic Biochemistry},
	author = {Solís, Verónica and Palopoli, Claudia and Daier, Verónica and Rivière, Eric and Collin, Fabrice and Moreno, Diego M. and Hureau, Christelle and Signorella, Sandra},
	year = {2018},
	pages = {29--36},
}

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