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Structural, Spectroscopic, and Thermal Decomposition Features of [Carbonatotetraamminecobalt(III)] Iodide—Insight into the Simultaneous Solid-Phase Quasi-Intramolecular Redox Reactions. INORGANICS 2023. [DOI: 10.3390/inorganics11020068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
[κ2-O,O′-Carbonatotetraamminecobalt(III)] iodide, or [Co(NH3)4CO3]I, named in this paper as compound 1, was prepared and characterized comprehensively with spectroscopic (IR, Raman and UV) and single-crystal X-ray diffraction methods. Compound 1 was orthorhombic, and isomorphous with the analogous bromide. The four ammonia ligands and the carbonate anion were coordinated to the central cobalt cation in a distorted octahedral geometry. The carbonate ion formed a four-membered symmetric planar chelate ring. The complex cations were bound to each other by N-H···O hydrogen bonds and formed zigzag sheets via an extended 2D hydrogen bond network. The complex cations and iodide ions were arranged into ion pairs and each cation bound its iodide pair through three hydrogen bonds. The thermal decomposition started with the oxidation of the iodide ion by CoIII in the solid phase resulting in [Co(NH3)4CO3] and I2. This intermediate CoII-complex in situ decomposed into Co3O4 and C-N bond containing intermediates. In inert atmosphere, CO or C-N bond containing compounds, and also, due to the in situ decomposition of CoCO3 intermediate, Co3O4 was formed. The quasi-intramolecular solid-phase redox reaction of [Co(NH3)4CO3] might have resulted in the formation of C-N bond containing compounds with substoichiometric release of ammonia and CO2 from compound 1. The C-N bond containing intermediates reduced Co3O4 into CoO and Co, whereas in oxygen-containing atmosphere, the end-product was Co3O4, even at 200 °C, and the endothermic ligand loss reaction coincided with the consecutive exothermic oxidation processes.
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[Hexaamminecobalt(III)] Dichloride Permanganate—Structural Features and Heat-Induced Transformations into (CoII,MnII)(CoIII,MnIII)2O4 Spinels. INORGANICS 2022. [DOI: 10.3390/inorganics10120252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
We synthesized and characterized (IR, Raman, UV, SXRD) hexaamminecobalt(III) dichloride permanganate, [Co(NH3)6]Cl2(MnO4) (compound 1) as the precursor of Co–Mn–spinel composites with atomic ratios of Co:Mn = 1:1 and 1:3. The 3D−hydrogen bond network includes N–HO–Mn and N–HCl interactions responsible for solid-phase redox reactions between the permanganate anions and ammonia ligands. The temperature-limited thermal decomposition of compound 1 under the temperature of boiling toluene (110 ∘C) resulted in the formation of (NH4)4Co2Mn6O12. which contains a todorokite-like manganese oxide network (MnII4MnIII2O1210−). The heat treatment products of compounds 1 and [Co(NH3)5Cl](MnO4)2 (2) synthesized previously at 500 ∘C were a cubic and a tetragonal spinel with Co1.5Mn1.5O4 and CoMn2O4 composition, respectively. The heating of the decomposition product of compounds 1 and 2 that formed under refluxing toluene (a mixture with an atomic ratio of Co:Mn = 1:1 and 1:2) and after aqueous leaching ((NH4)4Co2Mn6O12, 1:3 Co:Mn atomic ratio in both cases) at 500 ∘C resulted in tetragonal Co0.75Mn2.25O4 spinels. The Co1.5Mn1.5O4 prepared from compound 1 at 500 ∘C during the solid-phase decomposition catalyzes the degradation of Congo red with UV light. The decomposition rate of the dye was found to be nine times faster than in the presence of the tetragonal CoMn2O4 spinel prepared in the solid-phase decomposition of compound 2. The todorokite-like intermediate prepared from compound 1 under N2 at 115 ∘C resulted in a 54 times faster degradation of Congo red, which is a great deal faster than the same todorokite-like phase that formed from compound 2 under N2.
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Béres KA, Homonnay Z, Kvitek L, Dürvanger Z, Kubikova M, Harmat V, Szilágyi F, Czégény Z, Németh P, Bereczki L, Petruševski VM, Pápai M, Farkas A, Kótai L. Thermally Induced Solid-Phase Quasi-Intramolecular Redox Reactions of [Hexakis(urea- O)iron(III)] Permanganate: An Easy Reaction Route to Prepare Potential (Fe,Mn)O x Catalysts for CO 2 Hydrogenation. Inorg Chem 2022; 61:14403-14418. [PMID: 36044722 PMCID: PMC9477215 DOI: 10.1021/acs.inorgchem.2c02265] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
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Research on new reaction routes and precursors to prepare
catalysts
for CO2 hydrogenation has enormous importance. Here, we
report on the preparation of the permanganate salt of the urea-coordinated
iron(III), [hexakis(urea-O)iron(III)]permanganate
([Fe(urea-O)6](MnO4)3) via an affordable
synthesis route and preliminarily demonstrate the catalytic activity
of its (Fe,Mn)Ox thermal decomposition
products in CO2 hydrogenation. [Fe(urea-O)6](MnO4)3 contains O-coordinated urea ligands in octahedral
propeller-like arrangement around the Fe3+ cation. There
are extended hydrogen bond interactions between the permanganate ions
and the hydrogen atoms of the urea ligands. These hydrogen bonds serve
as reaction centers and have unique roles in the solid-phase quasi-intramolecular
redox reaction of the urea ligand and the permanganate anion below
the temperature of ligand loss of the complex cation. The decomposition
mechanism of the urea ligand (ammonia elimination with the formation
of isocyanuric acid and biuret) has been clarified. In an inert atmosphere,
the final thermal decomposition product was manganese-containing wuestite,
(Fe,Mn)O, at 800 °C, whereas in ambient air, two types of bixbyite
(Fe,Mn)2O3 as well as jacobsite (Fe,Mn)T-4(Fe,Mn)OC-62O4), with overall Fe to Mn stoichiometry of 1:3, were formed. These
final products were obtained regardless of the different atmospheres
applied during thermal treatments up to 350 °C. Disordered bixbyite
formed first with inhomogeneous Fe and Mn distribution and double-size
supercell and then transformed gradually into common bixbyite with
regular structure (and with 1:3 Fe to Mn ratio) upon increasing the
temperature and heating time. The (Fe,Mn)Ox intermediates formed under various conditions showed catalytic effect
in the CO2 hydrogenation reaction with <57.6% CO2 conversions and <39.3% hydrocarbon yields. As a mild solid-phase
oxidant, hexakis(urea-O)iron(III) permanganate, was
found to be selective in the transformation of (un)substituted benzylic
alcohols into benzaldehydes and benzonitriles. [Fe(urea-O)6](MnO4)3 is a selective solid-phase oxidant
of benzylic alcohols
into benzaldehydes and precursor in the preparation of (Fe,Mn)Ox catalysts for CO2 hydrogenation
into hydrocarbons. The urea ligands are in octahedral propeller-like
arrangement around the Fe3+ cation, and there are hydrogen
bonds between the permanganate anions and the urea ligands. A solid-phase
quasi-intramolecular redox reaction of the urea and the permanganate
resulted in (Fe,Mn)O, (Fe,Mn)2O3, and (Fe,Mn)T-4(Fe,Mn)OC-62O4 with an overall Fe to Mn stoichiometry of 1:3.
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Affiliation(s)
- Kende Attila Béres
- Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Magyar Tudósok krt. 2, H-1117 Budapest, Hungary.,György Hevesy PhD School of Chemistry, Institute of Chemistry, ELTE Eötvös Loránd University, Pázmány Péter s. 1/A, H-1117 Budapest, Hungary
| | - Zoltán Homonnay
- György Hevesy PhD School of Chemistry, Institute of Chemistry, ELTE Eötvös Loránd University, Pázmány Péter s. 1/A, H-1117 Budapest, Hungary
| | - Libor Kvitek
- Faculty of Science, Department of Physical Chemistry, Palacky University Olomouc, 17. Listopadu 12, Olomouc 77146, Czech Republic
| | - Zsolt Dürvanger
- Structural Chemistry and Biology Laboratory, Institute of Chemistry, ELTE Eötvös Loránd University, Pázmány Péter s. 1/A, H-1117 Budapest, Hungary
| | - Martina Kubikova
- Faculty of Science, Department of Physical Chemistry, Palacky University Olomouc, 17. Listopadu 12, Olomouc 77146, Czech Republic
| | - Veronika Harmat
- Structural Chemistry and Biology Laboratory, Institute of Chemistry, ELTE Eötvös Loránd University, Pázmány Péter s. 1/A, H-1117 Budapest, Hungary.,ELKH-ELTE Protein eModelling Research Group, Pázmány Péter s. 1/A, H-1117 Budapest, Hungary
| | - Fanni Szilágyi
- Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Magyar Tudósok krt. 2, H-1117 Budapest, Hungary.,Bay Zoltan Ltd. for Applied Research, Production Division (BAY-PROD), 1 Kondorfa, H-1116 Budapest, Hungary
| | - Zsuzsanna Czégény
- Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Magyar Tudósok krt. 2, H-1117 Budapest, Hungary
| | - Péter Németh
- Institute for Geological and Geochemical Research, Research Centre for Astronomy and Earth Sciences, ELKH, Budaörsi street 45, H-1112 Budapest, Hungary
| | - Laura Bereczki
- Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Magyar Tudósok krt. 2, H-1117 Budapest, Hungary
| | - Vladimir M Petruševski
- Faculty of Natural Sciences and Mathematics, Ss. Cyril and Methodius University, Skopje MK-1000, North Macedonia
| | - Mátyás Pápai
- Wigner Research Centre for Physics, H-1525 Budapest, P.O. Box 49, Hungary
| | - Attila Farkas
- Department of Organic Chemistry, Budapest University of Technology and Economics, Műegyetem rakpart 3, H-1111 Budapest, Hungary
| | - László Kótai
- Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Magyar Tudósok krt. 2, H-1117 Budapest, Hungary.,Deuton-X Ltd., Selmeci u. 89, H-2030, Érd, Hungary
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Structure and Vibrational Spectra of Pyridine Solvated Solid Bis(Pyridine)silver(I) Perchlorate, [Agpy2ClO4]·0.5py. INORGANICS 2022. [DOI: 10.3390/inorganics10090123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
A hemipyridine solvate of bis(pyridine)silver(I) perchlorate, [Agpy2ClO4]·0.5py (compound 1) was prepared and characterized by single crystal X-ray analysis and vibrational spectroscopy (R and low-temperature Raman). Compound 1 was prepared via the trituration of [Agpy2ClO4] and 4[Agpy2ClO4]·[Agpy4]ClO4 (as the source of the solvate pyridine) in a mixed solvent of acetone:benzene =1:1 (v = v) at room temperature. The monoclinic crystals of compound 1 were found to be isomorphic with the analogous permanganate complex (a = 19.1093(16) Å, b = 7.7016(8) Å, c = 20.6915(19) Å, β = 105.515(7)°; space group: C2/c). Two [Agpy2]+ cations formed a dimeric unit [Agpy2ClO4]2, and each silver ion was connected to two ClO4− anions via oxygen atoms. The Ag∙∙∙Ag distance was 3.3873(5) Å, the perchlorate ions were coordinated to silver ions, and the Ag∙∙∙O distances were 2.840(2) Å and 2.8749(16) Å in the centrosymmetric rectangle of Ag-O-Ag-O. The stoichiometric ratio of the monomer [Agpy2ClO4] and the solvent pyridine was 1:0.5. The guest pyridine occupied 527.2 Å3, which was 18.0% of the volume of the unit cell. There was no additional residual solvent-accessible void in the crystal lattice. The solvate pyridine was connected via its a-CH to one of the O atoms of the perchlorate anion. Correlation analysis, as well as IR and low-temperature Raman studies, were performed to assign all perchlorate and pyridine vibrational modes. The solvate and coordinated pyridine bands in the IR and Raman spectra were not distinguishable. A perchlorate contribution via Ag-O coordination to low-frequency Raman bands was also assigned.
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