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531.
H. G. von Schnering R. Türck W. Hnle K. Peters E.‐M. Peters R. Kremer J.‐H. Chang 《无机化学与普通化学杂志》2002,628(12):2772-2777
CsMn2P2, a Manganese(II, III) Phosphide with BaZn2P2 Structure. With a Contribution to the BaAl4 Structure Type CsMn2P22is formed by the reaction of Cs4P6 with Mn and red phosphorus (Nb ampoule; 1073 K) as black platelets. The compound is paramagnetic following the Curie‐Weiss law above 110 K (μ = 4.81 B.M. / CsMn2P2; θ = —79 K) and orders antiferromagnetically below 110 K. The magnetic moment corresponds with the ratio MnII : MnIII = 1:1. CsMn2P2 is isotypic with BaZn2P2 (tI10; I4/mmm; a = 4.098(1) Å, c = 14.215(4) Å, d(Mn—P) = 2.387(1) Å (4×), d(Cs—P) = 3.718(2) Å (8×)), and shows, therefore, no P—P‐bonds. The different regions of the BaAl4 (ThCr2Si2) structure type are analysed and parameterized once more. 相似文献
532.
533.
Structure and Magnetism of Fluorides Cs2MCu3F10 (M = Mg, Mn, Co, Ni), Variants of the CsCu2F5 Type X‐ray structure determinations of single crystals showed that compounds Cs2MCu3F10 crystallize with Z = 2 in space group P21/n (No.14) (M = Mn) of the CsCu2F5 type resp. in its supergroup I2/m (No.12) (M = Mg, Co, Ni). Cs2MgCu3F10: a = 714.9(1), b = 736.8(1), c = 940.4(1) pm, b = 96.29(1)°, (Mg‐F: 199.2 pm); Cs2MnCu3F10: a = 725.1(1), b = 742.7(1), c = 951.0(2) pm, b = 97.28(3)°, (Mn‐F: 209.1 pm); Cs2CoCu3F10: a = 717.8(3), b = 739.1(2), c = 939.4(4) pm, b = 97.49(2)°, (Co‐F: 203.1 pm); Cs2NiCu3F10: a = 716.3(1), b = 737.7(1), c = 938.2(2) pm, b = 97.09(1)°, (Ni‐F: 201.0 pm). As determined directly for the Mg compound and generally concluded from the average distances M‐F noted, M substitution concerns mainly the octahedrally coordinated position of the CsCu2F5 structure, the distortion of which is very much reduced thereby. Within the remaining [CuF4] and [CuF5] coordinations, in contrast to CsCu2F5, one F ligand is disordered, in case of the Mn compound the pyramidally coordinated Cu atom, too. The magnetic properties are complex and point to frustration and spin glass effects. Only at the diamagnetically substituted variants with M = Mg, Zn no Néel point appears, which is reached at 27, 23, 36 and 55 K for M = Mn, Co, Ni and Cu, resp. At lower temperatures ferri‐ resp. weak ferromagnetism and hysteresis is observed. 相似文献
534.
Co(C2(COO)2)(H2O)4 · 2 H2O and Co(C2(COO)2)(H2O)2: Two Co‐ordination Polymers of the Acetylenedicarboxylate Dianion By reaction of CoCO3 with an aqueous solution of acetylenedicarboxylic acid and subsequent crystallisation single‐crystals of Co(C2(COO)2)(H2O)4 · 2 H2O were obtained (P21/a, Z = 2). In the solid state structure cobalt is octahedrally surrounded by four water molecules and two oxygen atoms of the carboxylate anions. These octahedra are connected to chains by the dicarboxylates. Already at ambient conditions Co(C2(COO)2)(H2O)4 · 2 H2O looses four water molecules to give Co(C2(COO)2)(H2O)2 (isotypic to Mn[C2(COO)2] · 2 H2O, C2/c, Z = 4). The cobalt cation is now octahedrally co‐ordinated by two water molecules and four oxygen atoms of the dicarboxylate ligands, which connect the Co octahedra to a three dimensional network. Thermoanalytical investigations show another mass loss at about 200 °C, which leads to non‐crystalline products. Measurements of the magnetic susceptibilities result in the expected behaviour for Co2+ in an octahedral co‐ordination (high spin, 4T1 ground state). The effective magnetic moment at room temperature is neff = 5.51 μB. 相似文献
535.
运用第一性原理计算方法系统研究了二维单层β-GeS中取代掺杂不同3d过渡金属原子时体系磁性、能带结构和光学性质的变化.结果表明:相比于本征非磁性β-GeS,取代掺杂Ti~Cu导致β-GeS具有磁性,且磁矩呈现出先增加后减小的变化趋势;掺杂后体系能带结构发生明显变化,分别表现出金属,半金属和半导体性质,而且导带底的位置明显向Fermi能级方向移动.相比于本征体系,非本征体系的光学性质表明:其在一定波段范围内出现蓝移现象以及光响应强度发生变化,且掺杂前后体系均表现出高的各向异性. 相似文献
536.
Yao Jing Prof. Yukihiro Yoshida Prof. Tokutaro Komatsu Prof. Hiroshi Kitagawa 《Angewandte Chemie (International ed. in English)》2023,62(29):e202303778
A 2D-to-2D (2D: two-dimensional) structural transformation accompanying significant bond rearrangement and coordination environment change is demonstrated in a coordination polymer (CP) comprised of copper(II) ions and terephthalate (BDC2−) ligands for the first time. When immersed in water, a free-standing membrane of 2D Cu(BDC)(DMF) ( Cu-1 ; DMF: N,N-dimethylformamide) transforms into 2D Cu(BDC)(H2O)2 ( Cu-2 ) while maintaining its highly oriented layered structure. In the 2D sheet, paddlewheel-type CuII dimers coordinated with four bidentate BDC ligands in a square-planar array in Cu-1 were released to form uniform aqua-bridged CuII chains, which are cross-linked with each other by unidentate BDC ligands, in Cu-2 . The present facile approach to implement the 2D-to-2D transformation accompanied by bond rearrangement, which is characteristic of CPs, leads to a marked increase in in-plane magnetic susceptibility and proton conductivity. In situ experiments in support of theoretical calculations unveiled the energy diagram that governs the unique structural transformation. 相似文献
537.
Dr. Tulasi Prapakaran Dr. C. I. Sathish Prof. Jiabao Yi Prof. Ajayan Vinu Prof. Ramaswamy Murugavel 《欧洲无机化学杂志》2023,26(17):e202300071
Starting from sterically encumbered 2,6-di-tert-butylphenyl phosphate (dtbppH2) and co-ligand 3,5-dimethyl pyrazole (dmpz), it is possible to isolate either mono-, di- or tetranuclear copper phosphates by varying the copper source and making attendant changes in the reaction conditions. For example, reaction of copper nitrate with dtbppH2 and dmpz at 60 °C leads to the isolation of the mononuclear copper phosphate [Cu(dtbppH)2(dmpz)(MeOH)2] ( 1 ) as the only product. However, the use of copper acetate in place of copper nitrate and conducting the reaction at the room temperature leads to the formation of both dinuclear [Cu(dtbpp)(dmpz)2]2 ( 2 ) and tetranuclear [Cu2(dtbpp)(dmpz)2(OAc)(MeO)]2 ( 3 ) from the same reaction mixture. Compounds 2 and 3 could be isolated in pure form through fractional crystallization. Copper phosphates 1 – 3 have been characterized by both analytical and spectroscopic methods including EPR and magnetic measurements. The molecular structures of all three compounds were established through single crystal diffraction studies. Dc magnetic measurements indicate antiferromagnetic interactions between the metal centres in all the compounds. 相似文献
538.
Hui Zhang Prof. Jianchen Lu Xin-Jing Zhao Baijin Li Hangjing Zhou Yong Zhang Gefei Niu Boyu Fu Lei Gao Prof. Yuan-Zhi Tan Prof. Jinming Cai 《Angewandte Chemie (International ed. in English)》2023,62(52):e202315216
Nanographenes with zigzag edges, for example, anthenes, exhibit a unique nonbonding π-electron state, which can be described as a spin-polarized edge state that yields specific magnetic ground state. However, prior researches on the magnetism of anthenes with varying lengths on a surface is lacking. This study systematically fabricated anthenes with inherent zigzag carbon atoms of different lengths ranging from bisanthene to hexanthene. Their magnetic evolution on the Au(111) surface was analyzed through bond-resolved scanning probe techniques and density functional theory calculations. The analyses revealed a transition in magnetic properties associated with the length of the anthenes, arising from the imbalance between hybridization energy and the Coulomb repulsion between valence electrons. With the increasing length of the anthenes, the ground state transforms gradually from a closed-shell to an antiferromagnetic open-shell singlet, exhibiting a weak exchange coupling of 4 meV and a charge transfer-induced doublet. Therefore, this study formulated a chemically tunable platform to explore size-dependent π magnetism at the atomic scale, providing a framework for research in organic spintronics. 相似文献