绿色综合性实验:少溶剂固态化学反应制备二水四氯合钴(Ⅱ)酸铵

Green Comprehensive Experiment:Ammonium Tetrachlorodiaquacobaltate(Ⅱ)Prepared from Less Solvent Solid State Reaction

现有化学工业过程使用了大量的溶剂。溶剂的使用带来了费时费力和高污染风险的溶剂处理过程,而且因为化学平衡的出现降低了产率。本实验提供了一种使用少量溶剂,而且在反应结束时蒸去溶剂推动反应进行到底的少溶剂固态化学反应实例,对化学过程的绿色化及其观念的推广有重要意义。研究发现,固体氯化铵和六水合氯化钴的2∶1物质的量比混合物在35℃机械搅拌下的反应,在不加水时反应仅停留在表面;加少量水和溶液反应均存在化学平衡;但如果把水蒸干,反应混合物的XRD谱中只有(NH_(4))_(2)[CoCl_(4)(H_(2)O)_(2)]的衍射峰,基本看不到NH_(4)Cl的。

Modern chemical processes use a large amount of solvent,and with timely-and-costly solvent processing.Here,we report a less solvent solid state reaction that can make 100%completion,by using a little solvent and a method to evaporate it at the end of the reaction.It has been found that the reaction of solid CoCl_(2)·6H_(2)O and solid NH_(4)Cl in 1∶2 molar ratio with different amount of water at 35℃stops at surficial stage if no water is used,but it reaches its equilibrium if water is used,and produces sole(NH_(4))_(2)[CoCl_(4)(H_(2)O)_(2)]if water is being gradually removed at the end of the reaction,which confirms the deduction of thermodynamics on LSR.