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).
Krieble,Peiker
, p. 2326 (1933)
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.
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).