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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, Sajó IE, Lendvay G, Trif L, Petruševski VM, Barta-Holló B, Korecz L, Franguelli FP, László K, Szilágyi IM, Kótai L. Solid-Phase "Self-Hydrolysis" of [Zn(NH 3) 4MoO 4@2H 2O] Involving Enclathrated Water-An Easy Route to a Layered Basic Ammonium Zinc Molybdate Coordination Polymer. Molecules 2021; 26:4022. [PMID: 34209392 PMCID: PMC8272139 DOI: 10.3390/molecules26134022] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/22/2021] [Accepted: 06/23/2021] [Indexed: 11/16/2022] Open
Abstract
An aerial humidity-induced solid-phase hydrolytic transformation of the [Zn(NH3)4]MoO4@2H2O (compound 1@2H2O) with the formation of [(NH4)xH(1-x)Zn(OH)(MoO4)]n (x = 0.92-0.94) coordination polymer (formally NH4Zn(OH)MoO4, compound 2) is described. Based on the isostructural relationship, the powder XRD indicates that the crystal lattice of compound 1@2H2O contains a hydrogen-bonded network of tetraamminezinc (2+) and molybdate (2-) ions, and there are cavities (O4N4(μ-H12) cube) occupied by the two water molecules, which stabilize the crystal structure. Several observations indicate that the water molecules have no fixed positions in the lattice voids; instead, the cavity provides a neighborhood similar to those in clathrates. The @ symbol in the notation is intended to emphasize that the H2O in this compound is enclathrated rather than being water of crystallization. Yet, signs of temperature-dependent dynamic interactions with the wall of the cages can be detected, and 1@2H2O easily releases its water content even on standing and yields compound 2. Surprisingly, hydrolysis products of 1 were observed even in the absence of aerial humidity, which suggests a unique solid-phase quasi-intramolecular hydrolysis. A mechanism involving successive substitution of the ammonia ligands by water molecules and ammonia release is proposed. An ESR study of the Cu-doped compound 2 (2#dotCu) showed that this complex consists of two different Cu2+(Zn2+) environments in the polymeric structure. Thermal decomposition of compounds 1 and 2 results in ZnMoO4 with similar specific surface area and morphology. The ZnMoO4 samples prepared from compounds 1 and 2 and compound 2 in itself are active photocatalysts in the degradation of Congo Red dye. IR, Raman, and UV studies on compounds 1@2H2O and 2 are discussed in detail.
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Affiliation(s)
- Kende Attila Béres
- Research Centre for Natural Sciences, Magyar Tudósok Krt 2, 1117 Budapest, Hungary; (K.A.B.); (G.L.); (L.T.); (L.K.); (F.P.F.)
| | - István E. Sajó
- Szentagothai Research Centre, Environmental Analytical and Geoanalytical Research Group, University of Pécs, Ifjúság Útja 20, 7624 Pécs, Hungary;
| | - György Lendvay
- Research Centre for Natural Sciences, Magyar Tudósok Krt 2, 1117 Budapest, Hungary; (K.A.B.); (G.L.); (L.T.); (L.K.); (F.P.F.)
| | - László Trif
- Research Centre for Natural Sciences, Magyar Tudósok Krt 2, 1117 Budapest, Hungary; (K.A.B.); (G.L.); (L.T.); (L.K.); (F.P.F.)
| | - Vladimir M. Petruševski
- Faculty of Natural Sciences and Mathematics, Ss. Cyryl and Methodius University, 1000 Skopje, North Macedonia;
| | - Berta Barta-Holló
- Department of Chemistry, Biochemistry and Environmental Protection, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovica 3, 21000 Novi Sad, Serbia;
| | - László Korecz
- Research Centre for Natural Sciences, Magyar Tudósok Krt 2, 1117 Budapest, Hungary; (K.A.B.); (G.L.); (L.T.); (L.K.); (F.P.F.)
| | - Fernanda Paiva Franguelli
- Research Centre for Natural Sciences, Magyar Tudósok Krt 2, 1117 Budapest, Hungary; (K.A.B.); (G.L.); (L.T.); (L.K.); (F.P.F.)
- Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Műegyetem Rakpart 3, 1111 Budapest, Hungary;
| | - Krisztina László
- Department of Physical Chemistry and Materials Science, Budapest University of Technology and Economics, Műegyetem Rakpart 3, 1111 Budapest, Hungary;
| | - Imre Miklós Szilágyi
- Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Műegyetem Rakpart 3, 1111 Budapest, Hungary;
| | - László Kótai
- Research Centre for Natural Sciences, Magyar Tudósok Krt 2, 1117 Budapest, Hungary; (K.A.B.); (G.L.); (L.T.); (L.K.); (F.P.F.)
- Deuton-X Ltd., Selmeci u. 89, 2030 Érd, Hungary
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