Physico-chemical properties of 4-chloro-2-nitrobenzoates of Co(II), Ni(II), and Cu(II) were studied. The complexes were obtained as mono- and trihydrates with a metal ion to ligand ratio of 1:2. All analysed 4-chloro-2-nitrobenzoates are polycrystalline compounds with colours depending on the central ions: pink for Co(II), green for Ni(II), and blue for Cu(II) complexes. Their thermal decomposition was studied only in the range of 293–523 K, because it was found that on heating in air above 523 K 4-chloro-2-nitrobenzoates decompose explosively. Hydrated complexes lose crystallization water molecules in one step and anhydrous compounds are formed. The final products of their decomposition are the oxides of the respective transition metals. From the results it appears that during dehydration process no transformation of nitro group to nitrite takes place. The solubilities of analysed complexes in water at 293 K are of the order of 10–4–10–2 mol dm–3. The magnetic moment values of Co2+, Ni2+ and Cu2+ ions in 4-chloro-2-nitrobenzoates experimentally determined at 76–303 K change from 3.89 to 4.82 μB for Co(II) complex, from 2.25 to 2.98 μB for Ni(II) 4-chloro-2-nitrobenzoate, and from 0.27 to 1.44 μB for Cu(II) complex. 4-chloro-2-nitrobenzoates of Co(II), and Ni(II) follow the Curie–Weiss law. Complex of Cu(II) forms dimer.
研究了 Co(II)、Ni(II) 和 Cu(II) 的
4-氯-2-硝基苯甲酸盐的物理
化学性质。这些配合物以一
水和三
水形式获得,
金属离子与
配体的比例为 1:2。所有分析的
4-氯-2-硝基苯甲酸酯都是多晶体化合物,颜色取决于中心离子:Co(II) 复合物为粉红色,Ni(II) 复合物为绿色,Cu(II) 复合物为蓝色。研究人员只在 293-523 K 的范围内研究了它们的热分解,因为研究人员发现,在高于 523 K 的空气中加热时,
4-氯-2-硝基苯甲酸盐会发生爆炸性分解。
水合络合物一步失去结晶
水分子,形成无
水化合物。它们分解的最终产物是相应过渡
金属的氧化物。结果表明,在脱
水过程中,硝基没有转变为
亚硝酸盐。在 293 K 温度下,所分析的络合物在
水中的溶解度为 10-4-10-2 mol dm-3。在 76-303 K 温度下实验测定的
4-氯-2-硝基苯甲酸 4-
氯酯中 Co2+、Ni2+ 和 Cu2+ 离子的磁矩值,Co(II) 复合物从 3.89 μB 变为 4.82 μB,Ni(II)
4-氯-2-硝基苯甲酸 4-
氯酯从 2.25 μB 变为 2.98 μB,Cu(II) 复合物从 0.27 μB 变为 1.44 μB。
钴(II)和
镍(II)的
4-氯-2-硝基苯甲酸酯遵循居里-魏斯定律。Cu(II) 复合物形成二聚体。