540-69-2Relevant articles and documents
Occurrence of a rare 49·66 structural topology, chirality, and weak ferromagnetism in the [NH4][M II(HCOO)3] (M = Mn, Co, Ni) frameworks
Wang, Zheming,Zhang, Bin,Inoue, Katsuya,Fujiwara, Hideki,Otsuka, Takeo,Kobayashi, Hayao,Kurmoo, Mohamedally
, p. 437 - 445 (2007)
We report the synthesis, crystal structures, thermal, IR, UV-vis, and magnetic properties of a series of divalent transition metal formates, [NH 4][M(HCOO)3], where M = divalent Mn, Co, or Ni. They crystallize in the hexagonal chiral space group P6322. The structure consists of octahedral metal centers connected by the anti-anti formate ligands, and the ammonium cations sit in the channels. The chiral structure is a framework with the rarely observed 49·66 topology, and the chirality is derived from the handedness imposed by the formate ligands around the metals and the presence of units with only one handedness. The thermal properties are characterized by a decomposition at ca. 200°C. The three compounds exhibit an antiferromagnetic ground state at 8.4, 9.8, and 29.5 K for Mn, Co, and Ni, respectively. The last two display a weak spontaneous magnetization due to a small canting of the moments below the critical temperature, and the Co compound shows a further transition at lower temperatures. The isothermal magnetizations at 2 K show spin-flop fields of 600 Oe (Mn), 14 kOe (Co), and above 50 kOe (Ni) and a small hysteresis with a remnant magnetization of 25 cm3 G mol-1 (Co) and 50 cm3 G mol-1 (Ni) and coercive field of 400 Oe (Co) and 830 Oe (Ni).
Effects of Pressure on the Thermal Decomposition Kinetics and Chemical Reactivity of Nitromethane
Piermarini, G. J.,Block, S.,Miller, P. J.
, p. 457 - 462 (1989)
The effect of pressure and temperature on the melting point, thermal decomposition rate, and chemical reactivity of nitromethane have been studied.A diamond anvil high-pressure cell in conjunction with (1) an optical polarizing microscope for melting point and chemical reactivity observations and (2) an automated Fourier transform infrared instrument for thermal decomposition kinetic measurement was used.Both pressure and temperature were found to increase the rate of thermal decomposition, indicating an overall bimolecular reaction mechanism.However, the mechanism is complex and appears to vary over large changes in pressure.Nevertheless, a chemical mechanism is proposed that explains the bimulecularity and also accounts for the observed decomposition products, ammonium formate and water.A dynamic stress-induced catastrophic reaction in nitromethane, which appears to be crystal orientation dependent with respect to the applied stress, was found.Under the same conditions, deuteriated nitromethane did not exhibit this catastrophic reaction.
Catalytic hydrogenation of CO2from airviaporous silica-supported Au nanoparticles in aqueous solution
Lennox, R. Bruce,Li, Chao-Jun,Ni, Siting,Roy, Ranjan,Zhu, Jun
, p. 3740 - 3749 (2021/06/06)
The conversion of the ubiquitous greenhouse gas CO2to valuable organic products is much sought after. Herein, the hydrogenation of CO2to C1 products with an 80% yield in water is reported using a novel catalyst, porous-silica-supported Au nanoparticles (Au/SiO2). In the presence of a Lewis acid, boric acid, the Au/SiO2catalyst enables an efficient conversion of amine-captured CO2to methanol, formate, and formamide. A mechanistic study involving isotopic labelling suggests that methanol production in the catalytic process arises from the direct hydrogenation of formate. Most importantly, this one-pot, two-step process is able to convert CO2in air at ambient pressures to C1 products in the absence of an organic solvent. Furthermore, the catalyst is readily recycled without further purification or reactivation and shows no significant decrease in catalytic activity after four reaction cycles in a reusability test.
Facile hydrogenation of bicarbonate to formate in aqueous medium by highly stable nickel-azatrane complex
Sivanesan, Dharmalingam,Seo, Bongkuk,Lim, Choong-Sun,Kim, Hyeon-Gook
, p. 121 - 128 (2020/01/03)
Molecular catalyst-based direct hydrogenation of bicarbonate to formate in aqueous medium is a challenging research topic for the H2 storage. Finding a green and effective method for the bicarbonate to formate conversion with non-precious metal-based catalyst is vital to the practical application. We report the direct hydrogenation of bicarbonate to formate using a water soluble nickel-azatrane complex. Catalysts 1–5, designed and synthesized, were screened for the hydrogenation of bicarbonate to formate in aqueous medium; the best TON of 121 was obtained for catalyst 4 at 120 °C (60 bar). Introduction of isopropyl (2) and methyl (3 and 4) groups in the coordination environment of the metal center enhances the production of formate. Further, the hydrogenation of bicarbonate with CO2 promoted the formate production for catalyst 4 with a TON of 92 (3 h). The use of green solvent and non-precious metal catalyst makes this catalytic method environmentally sustainable.
Zn-catalyzed cyanation of aryl iodides
Zhao, Lulu,Dong, Yanan,Xia, Qiangqiang,Bai, Jianfei,Li, Yuehui
supporting information, p. 6471 - 6477 (2020/06/08)
We report the first example of zinc-catalyzed cyanation of aryl iodides with formamide as the cyanogen source. The transformation was promoted by the bisphosphine Nixantphos ligand. Under optimized conditions, a variety of electron-donating and electron-withdrawing aryl iodides were converted into nitrile products in good to excellent yields. This approach is an exceedingly simple and benign method for the synthesis of aryl nitriles and is likely to proceed via a dinuclear Zn-concerted catalysis.
Hydrogenation of Carbon Dioxide with Organic Base by PCIIP-Ir Catalysts
Takaoka, Satoko,Eizawa, Aya,Kusumoto, Shuhei,Nakajima, Kazunari,Nishibayashi, Yoshiaki,Nozaki, Kyoko
, p. 3001 - 3009 (2018/10/02)
Novel PCIIP-IrI monochloride complexes (1-Cl and 2-Cl) bearing a phosphine-carbene-phosphine pincer type ligand were synthesized. Reactions of 1-Cl with hexachloroethane, hydrogen chloride, and lithium triethylborohydride under a dihydrogen atmosphere afforded PCIIP-IrIII trichloride (1-Cl3), hydride dichloride (1-HCl2), and trihydride (1-H3) complexes, respectively. The strong electron-donating ability of carbene in PCIIP-Ir complexes was confirmed by X-ray crystallography and DFT calculations. Moreover, in complex 1-Cl, strong π back-donation from the iridium center to the carbene carbon was observed. Hydrogenation of CO2 with triethanolamine catalyzed by PCIIP-Ir complexes was investigated. The novel PCIIP-Ir complex 1-Cl exhibited a longer lifetime in comparison to the PNP-IrIII complex 3-H3: the turnover number of 1-Cl is significantly higher than that of 3-H3 (in 46 h, 1-Cl 230000 and 3-H3 54000).
A nanoporous nickel catalyst for selective hydrogenation of carbonates into formic acid in water
Wang, Tian,Ren, Dezhang,Huo, Zhibao,Song, Zhiyuan,Jin, Fangming,Chen, Mingwei,Chen, Luyang
, p. 716 - 721 (2017/08/17)
An efficient unsupported nanoporous nickel (NiNPore) material for the hydrogenation of carbonates to formic acid (FA) in water was investigated for the first time. NiNPore is an environmentally benign catalyst and it exhibited remarkable catalytic activity in the reduction of a wide range of carbonates to afford formic acid in excellent yields with high selectivity, and maximum values of 86.6% from NaHCO3 and even up to 92.1% from KHCO3 were obtained. The hydrogen pressure and pKa of the carbonates had a significant influence on the formation of FA. The catalyst was easily recovered and could be recycled at least five times without leaching and loss of activity. The present study demonstrated a potential application for the synthesis of FA from CO2 or carbonate compounds.
Selected paper development of highly active IrPNP catalysts for hydrogenation of carbon dioxide with organic bases
Aoki, Wataru,Wattanavinin, Natdanai,Kusumoto, Shuhei,Nozaki, Kyoko
supporting information, p. 113 - 124 (2016/01/27)
Methoxy-substituted PNP-iridium(III) complexes and pyrazine-based PNP-iridium(III) complexes were developed and used to hydrogenate carbon dioxide in the presence of triethanolamine as a base. The methoxy-substituted PNP-hydridodichloridoiridium complex (C-HCl2) showed the highest turnover number, 160000; this is the highest value ever reported with an organic base in an aqueous medium. The reactivities of these complexes, derived from their ligand modification, were further studied. The results were as follows. (i) The pyrazine-based PNP-trihydridoiridium complex undergoes release of dihydrogen to afford dihydridoamido complex, possibly because of easy dearomatization of the pyrazine ring. This process was reversible, i.e., B-H2amido can readily be converted back to B-H3 on exposure to dihydrogen. (ii) The p-methoxy-substituted dihydridochlorido complex showed facile disproportionation of the chloride anion on the iridium center; this is attributed to the electron-donating nature of the methoxypyridine backbone.
METHODS AND CATALYST SYSTEMS FOR CARBON DIOXIDE CONVERSION
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Paragraph 0164, (2016/06/06)
Disclosed herein are embodiments of a heterogeneous catalyst system and methods of using the same to convert CO2-derived compounds to formate, formic acid, or a mixture thereof. The disclosed heterogeneous catalyst systems exhibit superior reactivity and stability in comparison to homogeneous catalyst systems and also can convert a variety of CO2-derived compounds to formate, formic acid, or mixtures thereof, in high yields using economical and environmentally friendly reaction conditions.
Highly efficient hydrogen storage system based on ammonium bicarbonate/formate redox equilibrium over palladium nanocatalysts
Su, Ji,Yang, Lisha,Lu, Mi,Lin, Hongfei
, p. 813 - 816 (2015/06/02)
Abstract A highly efficient, reversible hydrogen storage-evolution process has been developed based on the ammonium bicarbonate/formate redox equilibrium over the same carbon-supported palladium nanocatalyst. This heterogeneously catalyzed hydrogen storage system is comparable to the counterpart homogeneous systems and has shown fast reaction kinetics of both the hydrogenation of ammonium bicarbonate and the dehydrogenation of ammonium formate under mild operating conditions. By adjusting temperature and pressure, the extent of hydrogen storage and evolution can be well controlled in the same catalytic system. Moreover, the hydrogen storage system based on aqueous-phase ammonium formate is advantageous owing to its high volumetric energy density. Revolution of H2 evolution? A highly efficient hydrogen storage-evolution process has been developed based on the ammonium bicarbonate/formate redox equilibrium over a carbon-supported palladium nanocatalyst. Ammonium ion improves the efficiencies of both the hydrogenation of bicarbonate and the dehydrogenation of formate. By adjusting the reaction temperature and pressure, the extent of chemical reaction of hydrogen storage and evolution can be well controlled within the same catalytic system.
