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  1. Article ; Online: Flexible Co(II)-and Ni(II)-Based Cationic 2D Metal–Organic Frameworks Based on a Charge-Neutral (O,O)-Donor Bridge

    Pavel A. Demakov / Konstantin A. Kovalenko / Alexander N. Lavrov / Vladimir P. Fedin

    Inorganics, Vol 11, Iss 259, p

    2023  Volume 259

    Abstract: Two new metal–organic frameworks based on highly flexible 1,4-diazabicyclo[2.2.2]octane N,N′-dioxide (odabco) ligands were successfully synthesized and characterized. Their crystallographic formulae are [M(DMF) 2 (odabco) 2 ](ClO 4 ) 2 ·dioxane, where M ... ...

    Abstract Two new metal–organic frameworks based on highly flexible 1,4-diazabicyclo[2.2.2]octane N,N′-dioxide (odabco) ligands were successfully synthesized and characterized. Their crystallographic formulae are [M(DMF) 2 (odabco) 2 ](ClO 4 ) 2 ·dioxane, where M 2+ = Co 2+ ( 1 ) and Ni 2+ ( 2 ), and DMF is N,N-dimethylformamide. The title compounds possess cationic 2D coordination networks filled with perchlorate anions and dioxane solvent molecules in the interlayer space, with 20% solvent accessible volume. Carbon dioxide adsorption measurements for desolvated samples 1a and 2a gave 511 m 2 /g and 377 m 2 /g specific surface areas, respectively, revealing the first example of gas adsorption properties in the structure based on a flexible odabco bridge, despite the presence of large counteranions within the positively charged network. Magnetization measurements for 1 , 1a , 2 and 2a reveal their paramagnetic nature to be in a reasonable agreement with crystal structures, and almost no solvent dependence of the magnetization characteristics. A decrease in the effective magnetic moment observed at low temperatures is attributed mostly to zero-field level-splitting in the octahedral Ni 2+ and Co 2+ ions.
    Keywords metal–organic framework ; coordination polymer ; cationic networks ; aliphatic ligands ; gas adsorption ; magnetic properties ; Inorganic chemistry ; QD146-197
    Subject code 333
    Language English
    Publishing date 2023-06-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: A Series of Metal–Organic Frameworks with 2,2′-Bipyridyl Derivatives

    Vadim A. Dubskikh / Aleksei A. Kolosov / Anna A. Lysova / Denis G. Samsonenko / Alexander N. Lavrov / Konstantin A. Kovalenko / Danil N. Dybtsev / Vladimir P. Fedin

    Molecules, Vol 28, Iss 2139, p

    Synthesis vs. Structure Relationships, Adsorption, and Magnetic Studies

    2023  Volume 2139

    Abstract: Five new metal–organic frameworks based on Mn(II) and 2,2′-bithiophen-5,5′-dicarboxylate (btdc 2– ) with various chelating N-donor ligands (2,2′-bipyridyl = bpy; 5,5′-dimethyl-2,2′-bipyridyl = 5,5′-dmbpy; 4,4′-dimethyl-2,2′-bipyridyl = 4,4′-dmbpy) [Mn 3 ( ...

    Abstract Five new metal–organic frameworks based on Mn(II) and 2,2′-bithiophen-5,5′-dicarboxylate (btdc 2– ) with various chelating N-donor ligands (2,2′-bipyridyl = bpy; 5,5′-dimethyl-2,2′-bipyridyl = 5,5′-dmbpy; 4,4′-dimethyl-2,2′-bipyridyl = 4,4′-dmbpy) [Mn 3 (btdc) 3 (bpy) 2 ]·4DMF, 1

    [Mn 3 (btdc) 3 (5,5′-dmbpy) 2 ]·5DMF, 2

    [Mn(btdc)(4,4;-dmbpy)], 3

    [Mn 2 (btdc) 2 (bpy)(dmf)]·0.5DMF, 4

    [Mn 2 (btdc) 2 (5,5′-dmbpy)(dmf)]·DMF, 5 (dmf, DMF = N,N-dimethylformamide) have been synthesized, and their crystal structure has been established using single-crystal X-ray diffraction analysis (XRD). The chemical and phase purities of Compounds 1 – 3 have been confirmed via powder X-ray diffraction, thermogravimetric, and chemical analyses as well as IR spectroscopy. The influence of the bulkiness of the chelating N-donor ligand on the dimensionality and structure of the coordination polymer has been analyzed, and the decrease in the framework dimensionality, as well as the secondary building unit’s nuclearity and connectivity, has been observed for bulkier ligands. For three-dimensional (3D) coordination polymer 1 , the textural and gas adsorption properties have been studied, revealing noticeable ideal adsorbed solution theory (IAST) CO 2 /N 2 and CO 2 /CO selectivity factors (31.0 at 273 K and 19.1 at 298 K and 25.7 at 273 K and 17.0 at 298 K, respectively, for the equimolar composition and the total pressure of 1 bar). Moreover, significant adsorption selectivity for binary C 2 –C 1 hydrocarbons mixtures (33.4 and 24.9 for C 2 H 6 /CH 4 , 24.8 and 17.7 for C 2 H 4 /CH 4 , 29.3 and 19.1 for C 2 H 2 /CH 4 at 273 K and 298 K, respectively, for the equimolar composition and the total pressure of 1 bar) has been observed, making it possible to separate on 1 natural, shale, and associated petroleum gas into valuable individual components. The ability of Compound 1 to separate benzene and cyclohexane in a vapor phase has also been analyzed based on the adsorption isotherms of individual components measured at 298 K. The ...
    Keywords manganese(II) ; metal-organic framework ; 2,2′-bithiophen-5,5′-dicarboxylic acid ; gas adsorption ; adsorption selectivity ; magnetic properties ; Organic chemistry ; QD241-441
    Subject code 290
    Language English
    Publishing date 2023-02-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article ; Online: Enhanced Adsorption Selectivity of Carbon Dioxide and Ethane on Porous Metal–Organic Framework Functionalized by a Sulfur-Rich Heterocycle

    Vadim A. Dubskikh / Konstantin A. Kovalenko / Anton S. Nizovtsev / Anna A. Lysova / Denis G. Samsonenko / Danil N. Dybtsev / Vladimir P. Fedin

    Nanomaterials, Vol 12, Iss 4281, p

    2022  Volume 4281

    Abstract: Porous metal–organic framework [Zn 2 (ttdc) 2 (bpy)] ( 1 ) based on thieno [3,2-b]thiophenedicarboxylate (ttdc) was synthesized and characterized. The structure contains intersected zig-zag channels with an average aperture of 4 × 6 Å and a 49% ( v/v ) ... ...

    Abstract Porous metal–organic framework [Zn 2 (ttdc) 2 (bpy)] ( 1 ) based on thieno [3,2-b]thiophenedicarboxylate (ttdc) was synthesized and characterized. The structure contains intersected zig-zag channels with an average aperture of 4 × 6 Å and a 49% ( v/v ) guest-accessible pore volume. Gas adsorption studies confirmed the microporous nature of 1 with a specific surface area (BET model) of 952 m 2 ·g –1 and a pore volume of 0.37 cm 3 ·g –1 . Extensive CO 2 , N 2 , O 2 , CO, CH 4 , C 2 H 2 , C 2 H 4 and C 2 H 6 gas adsorption experiments at 273 K and 298 K were carried out, which revealed the great adsorption selectivity of C 2 H 6 over CH 4 (IAST selectivity factor 14.8 at 298 K). The sulfur-rich ligands and double framework interpenetration in 1 result in a dense decoration of the inner surface by thiophene heterocyclic moieties, which are known to be effective secondary adsorption sites for carbon dioxide. As a result, remarkable CO 2 adsorption selectivities were obtained for CO 2 /CH 4 (11.7) and CO 2 /N 2 (27.2 for CO 2 :N 2 = 1:1, 56.4 for CO 2 :N 2 = 15:85 gas mixtures). The computational DFT calculations revealed the decisive role of the sulfur-containing heterocycle moieties in the adsorption of CO 2 and C 2 H 6 . High CO 2 adsorption selectivity values and a relatively low isosteric heat of CO 2 adsorption (31.4 kJ·mol –1 ) make the porous material 1 a promising candidate for practical separation of biogas as well as for CO 2 sequestration from flue gas or natural gas.
    Keywords metal–organic framework ; thieno[3,2-b]thiophenedicarboxylic acid ; gas adsorption ; adsorption selectivity ; benzene and cyclohexane separation ; Chemistry ; QD1-999
    Subject code 290 ; 333
    Language English
    Publishing date 2022-12-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article ; Online: Electrochemical Performance of Potassium Hydroxide and Ammonia Activated Porous Nitrogen-Doped Carbon in Sodium-Ion Batteries and Supercapacitors

    Yuliya V. Fedoseeva / Elena V. Shlyakhova / Svetlana G. Stolyarova / Anna A. Vorfolomeeva / Alina D. Nishchakova / Mariya A. Grebenkina / Anna A. Makarova / Konstantin A. Kovalenko / Alexander V. Okotrub / Lyubov G. Bulusheva

    Inorganics, Vol 10, Iss 198, p

    2022  Volume 198

    Abstract: Carbon nanomaterials possessing a high specific surface area, electrical conductivity and chemical stability are promising electrode materials for alkali metal-ion batteries and supercapacitors. In this work, we study nitrogen-doped carbon (NC) obtained ... ...

    Abstract Carbon nanomaterials possessing a high specific surface area, electrical conductivity and chemical stability are promising electrode materials for alkali metal-ion batteries and supercapacitors. In this work, we study nitrogen-doped carbon (NC) obtained by chemical vapor deposition of acetonitrile over the pyrolysis product of calcium tartrate, and activated with a potassium hydroxide melt followed by hydrothermal treatment in an aqueous ammonia solution. Such a two-stage chemical modification leads to an increase in the specific surface area up to 1180 m 2 g −1 , due to the formation of nanopores 0.6–1.5 nm in size. According to a spectroscopic study, the pore edges are decorated with imine, amine, and amide groups. In sodium-ion batteries, the modified material mNC exhibits a stable reversible gravimetric capacity in the range of 252–160 mA h g −1 at current densities of 0.05–1.00 A g −1 , which is higher than the corresponding capacity of 142–96 mA h g −1 for the initial NC sample. In supercapacitors, the mNC demonstrates the highest specific capacitance of 172 F g −1 and 151 F g −1 at 2 V s −1 in 1 M H 2 SO 4 and 6 M KOH electrolytes, respectively. The improvement in the electrochemical performance of mNC is explained by the cumulative contribution of a developed pore structure, which ensures rapid diffusion of ions, and the presence of imine, amine, and amide groups, which enhance binding with sodium ions and react with protons or hydroxyl ions. These findings indicate that hydrogenated nitrogen functional groups grafted to the edges of graphitic domains are responsible for Na + ion storage sites and surface redox reactions in acidic and alkaline electrolytes, making modified carbon a promising electrode material for electrochemical applications.
    Keywords N-doped porous carbon ; potassium hydroxide melt treatment ; ammonia treatment ; Na-ion batteries ; supercapacitors ; Inorganic chemistry ; QD146-197
    Subject code 333
    Language English
    Publishing date 2022-11-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  5. Article ; Online: Heteroleptic La III Anilate/Dicarboxylate Based Neutral 3D-Coordination Polymers

    Olesya Y. Trofimova / Arina V. Maleeva / Irina V. Ershova / Anton V. Cherkasov / Georgy K. Fukin / Rinat R. Aysin / Konstantin A. Kovalenko / Alexandr V. Piskunov

    Molecules, Vol 26, Iss 2486, p

    2021  Volume 2486

    Abstract: Three new 3D metal–organic frameworks of lanthanum based on mixed anionic ligands, [(La 2 (pQ) 2 (BDC) 4 )·4DMF] n , [(La 2 (pQ) 2 (DHBDC) 4 )·4DMF] n , [(La 2 (CA) 2 (BDC) 4 )·4DMF] n (pQ—dianion of 2,5-dihydroxy-3,6-di-tert-butyl-para-quinone, CA— ... ...

    Abstract Three new 3D metal–organic frameworks of lanthanum based on mixed anionic ligands, [(La 2 (pQ) 2 (BDC) 4 )·4DMF] n , [(La 2 (pQ) 2 (DHBDC) 4 )·4DMF] n , [(La 2 (CA) 2 (BDC) 4 )·4DMF] n (pQ—dianion of 2,5-dihydroxy-3,6-di-tert-butyl-para-quinone, CA—dianion of chloranilic acid, BDC-1,4-benzenedicarboxylate, DHBDC-2,5-dihydroxy-1,4-benzenedicarboxylate and DMF-N,N′-dimethylformamide), were synthesized using solvothermal methodology. Coordination polymers demonstrate the rare xah or 4,6T187 topology of a 3D framework. The homoleptic 2D-coordination polymer [(La 2 (pQ) 3 )·4DMF] n was obtained as a by-product in the course of synthetic procedure optimization. The thermal stability, spectral characteristics and porosity of coordination polymers were investigated.
    Keywords metal-organic framework ; lanthanum ; anilate ; carboxylate ; crystal structure ; thermal stability ; Organic chemistry ; QD241-441
    Language English
    Publishing date 2021-04-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  6. Article ; Online: 3D Metal–Organic Frameworks Based on Co(II) and Bithiophendicarboxylate

    Vadim A. Dubskikh / Anna A. Lysova / Denis G. Samsonenko / Alexander N. Lavrov / Konstantin A. Kovalenko / Danil N. Dybtsev / Vladimir P. Fedin

    Molecules, Vol 26, Iss 5, p

    Synthesis, Crystal Structures, Gas Adsorption, and Magnetic Properties

    2021  Volume 1269

    Abstract: Three new 3D metal-organic porous frameworks based on Co(II) and 2,2′-bithiophen-5,5′-dicarboxylate (btdc 2− ) [Co 3 (btdc) 3 (bpy) 2 ]·4DMF, 1 ... Co 3 (btdc) 3 (pz)(dmf) 2 ]·4DMF·1.5H 2 O, 2 ... Co 3 (btdc) 3 (dmf) 4 ]∙2DMF∙2H 2 O, 3 (bpy = 2,2′- ... ...

    Abstract Three new 3D metal-organic porous frameworks based on Co(II) and 2,2′-bithiophen-5,5′-dicarboxylate (btdc 2− ) [Co 3 (btdc) 3 (bpy) 2 ]·4DMF, 1

    [Co 3 (btdc) 3 (pz)(dmf) 2 ]·4DMF·1.5H 2 O, 2

    [Co 3 (btdc) 3 (dmf) 4 ]∙2DMF∙2H 2 O, 3 (bpy = 2,2′-bipyridyl, pz = pyrazine, dmf = N , N -dimethylformamide) were synthesized and structurally characterized. All compounds share the same trinuclear carboxylate building units {Co 3 (RCOO) 6 }, connected either by btdc 2– ligands ( 1 , 3 ) or by both btdc 2– and pz bridging ligands ( 2 ). The permanent porosity of 1 was confirmed by N 2 , O 2 , CO, CO 2 , CH 4 adsorption measurements at various temperatures (77 K, 273 K, 298 K), resulted in BET surface area 667 m 2 ⋅g −1 and promising gas separation performance with selectivity factors up to 35.7 for CO 2 /N 2 , 45.4 for CO 2 /O 2 , 20.8 for CO 2 /CO, and 4.8 for CO 2 /CH 4 . The molar magnetic susceptibilities χ p ( T ) were measured for 1 and 2 in the temperature range 1.77–330 K at magnetic fields up to 10 kOe. The room-temperature values of the effective magnetic moments for compounds 1 and 2 are μ eff (300 K) ≈ 4.93 μ B . The obtained results confirm the mainly paramagnetic nature of both compounds with some antiferromagnetic interactions at low-temperatures T < 20 K in 2 between the Co(II) cations separated by short pz linkers. Similar conclusions were also derived from the field-depending magnetization data of 1 and 2 .
    Keywords cobalt(II) ; metal–organic framework ; 2,2′-bithiophen-5,5′-dicarboxylic acid ; gas adsorption ; adsorption selectivity ; magnetic measurements ; Organic chemistry ; QD241-441
    Subject code 290
    Language English
    Publishing date 2021-02-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  7. Article ; Online: Hydrothermal Activation of Porous Nitrogen-Doped Carbon Materials for Electrochemical Capacitors and Sodium-Ion Batteries

    Yuliya V. Fedoseeva / Egor V. Lobiak / Elena V. Shlyakhova / Konstantin A. Kovalenko / Viktoriia R. Kuznetsova / Anna A. Vorfolomeeva / Mariya A. Grebenkina / Alina D. Nishchakova / Anna A. Makarova / Lyubov G. Bulusheva / Alexander V. Okotrub

    Nanomaterials, Vol 10, Iss 2163, p

    2020  Volume 2163

    Abstract: Highly porous nitrogen-doped carbon nanomaterials have distinct advantages in energy storage and conversion technologies. In the present work, hydrothermal treatments in water or ammonia solution were used for modification of mesoporous nitrogen-doped ... ...

    Abstract Highly porous nitrogen-doped carbon nanomaterials have distinct advantages in energy storage and conversion technologies. In the present work, hydrothermal treatments in water or ammonia solution were used for modification of mesoporous nitrogen-doped graphitic carbon, synthesized by deposition of acetonitrile vapors on the pyrolysis products of calcium tartrate. Morphology, composition, and textural characteristics of the original and activated materials were studied by transmission electron microscopy, X-ray photoelectron spectroscopy, near-edge X-ray absorption fine structure spectroscopy, infrared spectroscopy, and nitrogen gas adsorption method. Both treatments resulted in a slight increase in specific surface area and volume of micropores and small mesopores due to the etching of carbon surface. Compared to the solely aqueous medium, activation with ammonia led to stronger destruction of the graphitic shells, the formation of larger micropores (1.4 nm vs 0.6 nm), a higher concentration of carbonyl groups, and the addition of nitrogen-containing groups. The tests of nitrogen-doped carbon materials as electrodes in 1M H 2 SO 4 electrolyte and sodium-ion batteries showed improvement of electrochemical performance after hydrothermal treatments especially when ammonia was used. The activation method developed in this work is hopeful to open up a new route of designing porous nitrogen-doped carbon materials for electrochemical applications.
    Keywords porous nitrogen-doped carbon ; hydrothermal treatment ; XPS ; NEXAFS ; electrochemical double-layer capacitors ; sodium-ion batteries ; Chemistry ; QD1-999
    Subject code 620
    Language English
    Publishing date 2020-10-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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