Entering Crystal 8 | How to Cultivate Single Crystals? Several Methods of Single Crystal Cultivation

For many students studying crystal materials, as well as those studying drug formulations or generic drugs, cultivating single crystals can be said to be an insurmountable step. Research on crystal materials requires analysis of crystal structure and properties. For drug formulations or generic drugs, it is necessary to control crystal form or screen for polycrystalline/solvates, etc. In this issue, we will introduce to you the single crystal cultivation methods that the editor often uses or has heard of.

The sublimation method is used in relatively few places. If none of the above cultivation methods can cultivate single crystals and the solute is prone to sublimation under heating conditions, then sublimation crystallization can be attempted. By heating, the solute sublimates and then condenses and crystallizes when it encounters a cooled surface above.

The above methods are basically conventional cultivation methods for organic crystals, and there are also some relatively rare or specific single crystal cultivation methods used in certain fields, such as contact interface crystallization, hydrothermal crystallization, and vapor deposition. Contact interface crystallization and hydrothermal crystallization methods are commonly used for the crystallization of organic-inorganic complexes. Briefly explain the contact crystallization method, which can easily synthesize complexes from two or more species, has high selectivity, and the formed complexes are difficult to dissolve in solvents. This can slowly contact the raw materials, form crystal nuclei at the contact point, and then grow to form single crystals. The contact crystallization method can be carried out using U-shaped tubes or other glassware. The vapor deposition method is commonly used in the field of semiconductors or metal materials.

The above is an introduction to single crystal cultivation methods, mainly focusing on the crystallization of small organic molecules. In fact, different single crystal cultivation methods use different methods to slowly increase the driving force and cross the nucleation energy barrier to achieve crystallization. It is recommended that everyone try different single crystal cultivation methods simultaneously, especially if you need to cultivate polycrystalline crystals, because different single crystal cultivation methods may obtain different crystal forms.