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maple_5211

木虫 (小有名气)

[求助] 请教一下钼钒杂多酸的重结晶具体方法已有1人参与

之前做了几中钼钒磷杂多酸,做了ICP,感觉钼 、钒、 磷的比例不是很对,我觉得可能是重结晶的不好,杂质太多,求大家指教下重结晶的具体方案,感觉杂多酸在水中溶解度太大了,热过滤的话是不是损失的太多啊?还有如果有高人有更好的制备纯净的H4PMo11VO4•xH2O、H5PMo10V2O40•xH2O 、H6PMo9V3O40•xH2O 也请帮忙说下,十分感谢啊!
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yingkai

金虫 (正式写手)

引用回帖:
12楼: Originally posted by jlupce at 2018-10-03 04:00:33
这种合成方法费时费力,合成样品组成也不固定,建议换个合成方法,合成杂多酸经典方法有的是,找下老些的文献...

您好,谢谢您抽出宝贵的时间替我回复,也找到了类似的相关的合成的其他方法,如:11-Molybdo-l-vanadophosphoric Acid.—Na2HP04, 7.1 g, was dissolved in 100 ml of water and mixed with 6.1 g of sodium metavanadate that had been dissolved by boiling in 100 ml of water. The mixture was cooled and acidified to a red color with 5 ml of concentrated sulfuric acid. To this mixture was added a solution of 133 g of Na2Mo04-2H20 dissolved in 200 ml of water. Finally, 85 ml of concentrated sulfuric acid was added slowly with vigorous stirring of the solution. With this addition the dark red color changed to a lighter red. The heteropoly acid was then extracted with 400 ml of ethyl ether after the water solution was cooled. In this extraction, the heteropoly etherate was present as a middle layer; the bottom layer (water) was yellow and probably contained vanadyl species. After separation, a stream of air was passed through the heteropoly etherate layer to free it of ether. The orange solid that remained was dissolved in 50 ml of water, concentrated to the first appearance of crystals in a vacuum desiccator over concentrated sulfuric acid, and then allowed to crystallize further. The orange crystals that formed were filtered, washed with water, and air dried. The yield was 28 g. The crystalline acid effloresces slowly at room temperature; thus the amount of water of crystallization varied slightly from sample to sample.  Reference: Molybdovanadophosphoric Acids and Their Salts. I. Investigation of Methods of Preparation and Characterization.(1968),这种方法我个人觉得也不简单,还需要调节PH ,更加的麻烦,请问您一般用什么方法合成呢?
13楼2018-10-03 20:12:50
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smq712

银虫 (初入文坛)

【答案】应助回帖

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jiangyun2: 金币+1, 应助指数+1, 谢谢回帖交流,欢迎常来~~ 2013-11-19 09:01:17
maple_5211(jiangyun2代发): 金币+10 2013-11-29 09:14:38
我也重结晶过  5%硫酸,真空干燥箱  没了
2楼2013-11-18 23:01:40
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maple_5211

木虫 (小有名气)

引用回帖:
2楼: Originally posted by smq712 at 2013-11-18 23:01:40
我也重结晶过  5%硫酸,真空干燥箱  没了

就加5%的硫酸,然后热过滤,在干燥就OK了?
3楼2013-11-19 08:57:42
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smq712

银虫 (初入文坛)

【答案】应助回帖

引用回帖:
3楼: Originally posted by maple_5211 at 2013-11-19 08:57:42
就加5%的硫酸,然后热过滤,在干燥就OK了?...

热过滤得加过氧化氢  要不该绿了

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4楼2013-11-20 21:03:56
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