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941.
Lorena Capdevila Judith Sala Prof. Dr. Lutz Ackermann Dr. Xavi Ribas 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(29):e202200625
A Ni-catalyzed Csp2−OMe ortho-functionalization methodology to form chemoselectively alkyne monoannulation or aromatic homologation products is reported as a novel protocol towards the valorisation of substrates containing Csp2−OMe units. Double activation of Csp2−OMe and Csp2−F bonds is also demonstrated. Further use of aromatic homologation products towards the synthesis of nanographene-like compounds is described. 相似文献
942.
Kamila Pruszkowska Olga A. Stasyuk Anna Zep Adam Krówczyński Rafal R. Sicinski Miquel Solà Michał K. Cyrański 《Chemphyschem》2022,23(2):e202100741
Two new square planar ONNO nickel(II) complexes C2_core and C3_core have been synthesized and characterized by single crystal X-ray diffraction, NMR spectroscopy, thermogravimetry, and DFT calculations. The experimental results revealed the effect of the length of diamine bridge in the ligand on the behavior of the studied complexes in the reaction with N-heterocyclic aromatic amines, while DFT calculations provided a basis for the rationalization of this observation. The complex with propylenediamine bridge ( C3_core ) readily reacts with pyridine and its derivatives to form high-spin (paramagnetic) complexes with octahedral geometry as characterized by X-ray diffraction; electron-donating substituents on the pyridine ring facilitate the coordination of axial ligands. In contrast, the complex with ethylenediamine bridge ( C2_core) does not undergo such a reaction because of the high deformation energy of the core required for the formation of C2_Py complex. 相似文献
943.
Tarlok Singh Lobana Mani Kaushal Robin Bhatia Ritu Bala Ray J. Butcher Jerry P. Jasinksi 《Acta Crystallographica. Section C, Structural Chemistry》2022,78(1):30-35
In this investigation, the crystal structures of the thio-ligands 3-formylpyridine 4-phenylthiosemicarbazone (C13H12N4S, 1 ) and 4-benzoylpyridine 4-ethylthiosemicarbazone (C15H16N4S, 2 ), and of two new coordination compounds, chlorido(3-formylpyridine 4-phenylthiosemicarbazone-κS)bis(triphenylphosphane-κP)copper(I) acetonitrile monosolvate, [CuCl(C13H12N4S)(C18H15P)2]·CH3CN, 3 , and bis(3-formylpyridine 4-ethylthiosemicarbazonato-κ2N1,S)nickel(II), [Ni(C9H11N4S)2], 4 , are reported. In complex 3 , the thio-ligand coordinates in a neutral form to the Cu atom through its S-donor atom, and in complex 4 , the anionic thio-ligand chelates to the Ni atom through N- and S-donor atoms. The geometry of complex 3 is distorted tetrahedral [bond angles 99.70 (5)–123.23 (5)°], with the P—Cu—P bond angle being the largest, while that of complex 4 is square planar, with trans-S—Ni—S and N—Ni—N bond angles of 180°. 相似文献
944.
Dr. Girish D. Salian Dr. Jonathan Højberg Dr. Christian Fink Elkjær Yonas Tesfamhret Dr. Guiomar Hernández Dr. Matthew J. Lacey Assoc. Prof. Dr. Reza Younesi 《ChemistryOpen》2022,11(6):e202200065
Two water-soluble binders of carboxymethyl cellulose (CMC) and sodium alginate (SA) have been studied in comparison with N-methylpyrrolidone-soluble poly(vinylidene difluoride–co-hexafluoropropylene) (PVdF-HFP) to understand their effect on the electrochemical performance of a high-voltage lithium nickel manganese oxide (LNMO) cathode. The electrochemical performance has been investigated in full cells using a Li4Ti5O12 (LTO) anode. At room temperature, LNMO cathodes prepared with aqueous binders provided a similar electrochemical performance as those prepared with PVdF-HFP. However, at 55 °C, the full cells containing LNMO with the aqueous binders showed higher cycling stability. The results are supported by intermittent current interruption resistance measurements, wherein the electrodes with SA showed lower resistance. The surface layer formed on the electrodes after cycling has been characterized by X-ray photoelectron spectroscopy. The amount of transition metal dissolutions was comparable for all three cells. However, the amount of hydrogen fluoride (HF) content in the electrolyte cycled at 55 °C is lower in the cell with the SA binder. These results suggest that use of water-soluble binders could provide a practical and more sustainable alternative to PVdF-based binders for the fabrication of LNMO electrodes. 相似文献
945.
Bi‐Yun Su Xiao‐Teng Li Jia‐Xiang Wang Xu‐Dong Wang 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(12):1053-1056
<!?tlsb=‐0.2pt>Nitrogen‐based polydentate ligands are of interest owing to their flexible complexation to transition metal atoms. For the title compound, [Ni(C15H17N2)2], a transition metal complex formed by the coordination of two identical N,N′‐bidentate mono(imino)pyrrolyl ligands to an NiII centre, an X‐ray crystal diffraction study indicates that the two ligands show an inverted arrangement with respect to one another around the NiII centre, which is located on a crystallographic inversion centre. The planes of the aromatic substituents at the imine N atoms of the ligands show dihedral angles of 85.91 (5)° with respect to the NiN4 plane. The Ni—N bond lengths are in the range 1.9072 (15)–1.9330 (15) Å and the Nimino—Ni—Npyrrole bite angles are 83.18 (6)°. The Ni—Npyrrole bond is substantially shorter than the Ni—Nimino bond. Molecules are linked into an extensive network by means of intermolecular C—H...π(arene) hydrogen bonds in which every molecule acts both as hydrogen‐bond donor and acceptor. The supramolecular assembly takes the form of an infinite two‐dimensional sheet. 相似文献
946.
Ultralong α‐Ni(OH)2 nanobelts with uniform size have been prepared on large scale via a facile template‐free hydrothermal method. The as‐prepared nanobelts were single crystals, with several tens of microns in length and about 100 nm in width. For the whole process, a novel nucleation–aggregation–dissolution–seed‐directed growth mechanism was proposed based on the experimental results. The roles of aqueous ammonia and hydrothermal temperature were also discussed. Furthermore, porous NiO nanobelts were obtained by annealing the as‐prepared Ni(OH)2 nanobelts. This facile, template‐free, and low cost method might feasibly be scaled up for industrial production. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
947.
A novel malic acid assisted precursor route to prepare NiO materials with novel hierarchical structures has been investigated in this work. The Ni‐based precursors can be synthesized by a malic acid‐assisted hydrothermal route, which have been characterized by powder X‐ray diffraction (XRD), field‐emission scanning electron microscopy (FE‐SEM), thermogravimetric analysis (TGA). NiO materials can be prepared via the thermal treatment of the precursor in ambient atmosphere. The XRD, SEM, Energy dispersive X‐ray spectroscopy (EDS) and UV‐Vis spectroscopy of the NiO materials were also examined. The effects of the reaction conditions, such as the reaction temperature, the quantity of the raw materials on the morphologies of the precursors were discussed, which indicates that it is an effective method to synthesize NiO materials with different hierarchical structures. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
948.
以胶原纤维 (CF) 接枝表棓儿茶素棓酸酯 (EGCG) 为载体, 制备了新型 Pd-Ni/CF-EGCG 催化剂. EGCG 作为“桥分子”对 Pd-Ni 纳米粒子起着分散和锚定作用. 通过热重分析、扫描电镜、透射电镜、X 射线光电子能谱和 X 射线衍射对该催化剂进行了表征. 结果表明, 该催化剂具有规整的纤维结构, 在纤维表面形成了高分散的平均粒径为 2.2 nm 的 Pd-Ni 合金颗粒. 液相硝基苯催化加氢反应结果表明, 当 Ni 和 Pd 摩尔比为 0.8 时, Pd-Ni/CF-EGCG 催化剂具有最佳的双金属协同作用, 在 308 K 和 1.0 MPa 氢压下, 加氢速率达 237 min?1, 比单金属的 Pd/CF-EGCG 快 1 倍, 重复使用 5 次后仍具有较高的催化活性. 相似文献
949.
常压两步法催化丙三醇脱水-加氢制备 1,2-丙二醇 总被引:2,自引:0,他引:2
在常压 H2 气氛下催化丙三醇脱水-加氢制备了 1,2-丙二醇. 首先在 220 oC 和常压 H2 条件下, 以 Cu/Al2O3 为催化剂催化丙三醇脱水生成中间体丙酮醇, 其选择性高达 86%. 考察了 Cu 负载量、反应温度和反应气氛对催化剂性能的影响. 在随后的丙酮醇加氢反应中, Raney Ni 催化剂显示出优异的催化性能, 在 120 oC 和常压 H2 条件下, 1,2-丙二醇选择性可达 99% 以上, 催化剂连续使用 5 h 未出现失活现象. 考察了反应温度、空速及反应时间对催化剂性能的影响. 相似文献
950.
采用共沉淀-水热法合成了一系列 Ni/MgAl(O) 催化剂. 用甲苯和萘的混合物作为焦油模型化合物, 在固定床反应器上研究了该催化剂直接催化转化具有较低水蒸气/碳摩尔比的高温焦炉煤气中焦油为小分子气体的反应. 考察了催化剂组成、水蒸气/碳摩尔比和反应条件等对催化剂性能的影响. 结果表明, Mg/Al 摩尔比为 3 时 Ni/MgAl(O) 催化剂表现出最优的催化性能. 在 700~800 oC 和水蒸气/碳摩尔比为 0.68 的反应条件下, 15%Ni/Mg3Al(O) 催化剂能将甲苯和萘完全转化为 CO 和 CH4 等小分子气体. 在反应气中引入 0.05% H2S(摩尔分数) 气体的实验表明, 该催化剂在焦油催化转化反应中具有较好的抗硫能力. 另外, 在催化剂中加入少量 Pt 助剂能显著提高催化剂活性. 相似文献