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lynn19520

铁虫 (小有名气)

应助: 0 (幼儿园)
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在线: 147.5小时
虫号: 2178552
注册: 2012-12-10
性别: GG
专业: 质谱分析

[求助] 抗衡离子，培养晶体方法，麻烦告知，先行谢过！

Counterions. If your compound is ionic, and is not giving suitable crystals with a given counterion, perform a metathesis reaction to change the counterion. Very often the crystal quality will improve when a different counterion used. Ions of similar size tend to pack together better and subsequently give better crystals. In addition, you might also get more desirable physical properties for your crystal. For example, the sodium salt of your compound might be hygroscopic, but the tetramethyl ammonium salt might not be or at least, less so. When selecting possible counterions, avoid ions which contain large non-rigid groups (like tetrabutyl ammonium). Use ions which have very limited conformational flexibility. A word of warning: make sure that whatever ion you use for your metathesis does not react with your ion of interest.
这段话怎么解释？这种方法培养晶体具体怎么做？有具体事例吗？

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