Herein, we report the manganese complex with a novel trianionic ligand, the pentafluorophenyldipyrrinphenol ligand DPPH(3). The X-ray crystal structure reveals that the Mn(III) complex exists in a dimeric form in the solid state. Electrochemical studies indicate two quasi-reversible one electron oxidation processes. EPR data on the one electron oxidised species in solution support the formation of a monuclear Mn complex with an S = 3/2 spin system. Preliminary studies towards epoxidation reactions were tested in the presence of iodosylbenzene (PhIO) and are in favour of an oxygen-atom-transfer (OAT) reaction catalyzed by the Mn(III) complex.
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http://dx.doi.org/10.1039/c1dt10868a | DOI Listing |
J Hazard Mater
December 2024
Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China; National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Institute of Eco-Chongming, Fudan University, Shanghai 200062, China; Institute of Atmospheric Sciences, Fudan University, Shanghai 200438, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China. Electronic address:
Although trivalent manganese (Mn(III)) species have been recognized as crucial intermediates in the degradation of organic contaminants by Mn oxides, quantitative research on their specific roles remains scarce. Our study investigated the degradation processes of an organic pollutant, Bisphenol A (BPA), by dissolved Mn(III) and Mn(III)-bearing oxides, and elucidated the differences of the underlying mechanisms and reaction pathways between several Mn oxides and dissolved Mn(III). Our results indicated that BPA degradation rates with Mn(III)-bearing oxides alone follow the order: δ-MnO ≫ γ-MnOOH > MnO.
View Article and Find Full Text PDFChemistry
December 2024
Universidad Complutense de Madrid, Organic Chemistry, SPAIN.
The synthesis and characterization of novel compounds (5-8) as mimetics of [FeFe]-hydrogenase, combining two distinct systems capable of participating in hydrogen evolution reactions (HER): the [(μ-adt)Fe2(CO)6] fragment and M-salen complexes (salen = N,N'-bis(salicylidene)ethylenediamine) (M = Zn, Ni, Fe, Mn), is reported. These complexes were synthesized in high yields via a three-step procedure from N,N'-bis(4-R-salicylidene)ethanediamine) 4 [R = Fe2(CO)6(μ-SCH2)2COCH2O)]. Structural analysis through spectroscopic, spectrometric, and computational (DFT) methods confirmed distorted tetrahedral and square-planar geometries for Zn-salen and Ni-salen complexes (5 and 6) respectively, while complexes Fe-salen 7 and Mn-salen 8 exhibit square-based pyramidal structures typical of Fe(III) and Mn(III) high-spin salen-complexes.
View Article and Find Full Text PDFACS Omega
December 2024
Department of Chemistry, Panskura Banamali College, Panskura RS, West Bengal 721152, India.
In this study, a tetradentate Schiff-base ligand (HL), synthesized by the condensation of ethylenediamine with 2-hydroxy-3-methoxy-5-methylbenzaldehyde, was reacted with either manganese salts or manganese salts in the presence of various pseudohalides in methanol. This reaction resulted in the formation of five mononuclear Mn complexes: [Mn(L)(HO)](NO)·1/2HO·1/2CHOH (), [Mn(L)(HO)](ClO)·HO (), [Mn(L)(N)(HO)]·1/3HO (), [Mn(L)(NCS)(HO)] (), and [Mn(L)(HO)](dca) () (where dca is dicyanamide ion). X-ray crystallography revealed that the Mn centers adopt a hexa-coordinate pseudo-octahedral geometry, where the equatorial plane is constructed with phenoxo oxygen and imine nitrogen atoms from the Schiff base ligand, while the axial positions are occupied by water molecules or a combination of water and pseudohalides.
View Article and Find Full Text PDFWater Sci Technol
December 2024
School of Resources and Environment, Wuhan Textile University, Engineering Research Centre for Clean Production of Textile Dyeing and Printing, Ministry of Education, Wuhan 430073, China; State Key Laboratory of New Textile Materials and Advanced Processing Technologies, Wuhan Textile University, Wuhan 430200, China E-mail:
Engineered nanomaterials are widely used in water and wastewater treatment processes, and minimizing their adverse effects on biological treatment processes in wastewater treatment plants has become the primary focus. In this study, activated carbon fiber (ACF)-loaded manganese oxide nanomaterials (MnOx@ACF) were synthesized. A small-scale sequencing batch reactor (SBR) was constructed to simulate the synergistic degradation of pollutants by nanomaterials and microorganisms and the effects of nanomaterials on the structure of the microbial community in a wastewater treatment plant.
View Article and Find Full Text PDFDalton Trans
January 2025
Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada.
The synthesis of Mn and Cr nitride complexes of a pro-radical tetradentate bis-phenol bis-N-heterocyclic carbene ligand H2LC2O2 was investigated. Employing either azide photolysis of the Mn precursor complex MnLC2O2(N3) or a nitride exchange reaction between MnLC2O2(Br) and the nitride exchange reagent Mnsalen(N) failed to provide a useful route to the target nitride MnLC2O2(N). Experimental results support initial formation of the target nitride MnLC2O2(N), however, the nitride rapidly inserts into a Mn-C bond.
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