Preparation and crystal structures of Ni(NH3)2Cl2 and of two modifications of Ni(NH3)2Br2 and Ni(NH3)2I2
Preparation and crystal structures of Ni(NH3)2Cl2 and of two modifications of Ni(NH3)2Br2 and Ni(NH3)2I2
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DOI：
10.1006/jssc.2000.8666
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发表时间：
2000-07-01
影响因子：
3.3
通讯作者：
Jacobs, H
中科院分区：
文献类型：
--
作者：
Leineweber, A;Jacobs, H
在120 ℃动态真空条件下，通过六胺的分解反应制备了二氨镍卤化物Ni（NH_3）（2）X-2（X = Cl，Br，I）。它们的晶体结构为Cd（NH 3）（2）Cl-2型（“β型”，空间群Cmmm，Z = 2）：Ni（NH 3）（2）Cl-2，a = 8.019埃，B = 8.013埃，c = 3.661埃; β-Ni（NH 3）（2）Br-2，a = 8273埃，B = 8.297埃，c = 3.851埃。两者都是通过Rietveld对衍射仪数据进行精修获得的，标准偏差< 0.001埃。对于β-Ni（NH 3）（2）I-2，a = B = 8.753（3）埃，c = 4.127（1）埃，通过Guinier薄膜数据获得。在溴化物和碘化物的情况下，在300摄氏度下退火导致不可逆的结构重排。形成了一种新的Mg（NH_3）（2）Br-2型变质剂（“α-型”，空间群Pbam，Z = 2）：对于α-Ni（NH3）（2）Br-2，a = 5.86519，B = 11.723埃，c = 3.856埃，通过Rietveld对具有标准偏差的衍射仪数据进行精修获得（0.001;对于α-Ni（NH 3）（2）I-2，2a = B = 12.359（3）埃，c = 4.126（1）埃，由Guinier薄膜数据获得。这两种类型的结构都包含共享边八面体的无限链（1）（无穷大）[NiX 4/2（NH 3）（2）]。这些运行平行于相应的结构类型的晶胞的c轴，并以不同的方式相对于彼此排列，六氨合镍（II）卤化物的分解相应的二胺进行了分析，在结构类比。(C)北京大学出版社.
Diammine nickel(II) halides, Ni(NH3)(2)X-2 (X = Cl, Br, I), were prepared by decomposition of the corresponding hexaammines at 120 degrees C in dynamical vacuum. Their crystal structures are of the Cd(NH3)(2)Cl-2 type ("beta-type", space group Cmmm, Z = 2): for Ni(NH3)(2)Cl-2, a = 8.019 Angstrom, b = 8.013 Angstrom, c = 3.661 Angstrom; for beta-Ni(NH3)(2)Br-2, a = 8 273 Angstrom, b = 8.297 Angstrom, c = 3.851 Angstrom. Both were obtained by Rietveld refinement of diffractometer data with standard deviations < 0.001 Angstrom, For beta-Ni(NH3)(2)I-2, a = b = 8.753(3) Angstrom, c = 4.127(1) Angstrom, obtained by Guinier film data. In the case of the bromide and the iodide, annealing at 300 degrees C leads to an irreversible structural rearrangement. A new modification is formed which is of the Mg(NH3)(2)Br-2 type ("alpha-type", space group Pbam, Z = 2): for alpha-Ni(NH3)(2)Br-2, a = 5.86519, b = 11.723 Angstrom, c = 3.856 Angstrom, obtained by Rietveld refinement of diffractometer data with standard deviations (0.001; for alpha-Ni(NH3)(2)I-2, 2a = b = 12.359(3) Angstrom, c = 4.126(1) Angstrom, obtained by Guinier film data. Both types of structures contain infinite chains of edge-sharing octahedra (1)(infinity)[NiX4/2(NH3)(2)]. These run parallel to the c-axes of the unit cells of the corresponding structure types and are arranged in different ways relative to one another, The decomposition of hexaammine nickel (II) halides to the corresponding diammines is analyzed in terms of structural analogies. (C) 2000 Academic Press.