I think the following link give better explanation

http://web.mit.edu/x-ray/cystallize.html

But I need the best method for single crystal preparation of organic compounds, which are viscous in nature.

Hi Preethanuj,

Indeed it is daunting to crystallize something which has less tendency to crystallize.

I am proposing some of the following techniques assuming that your sample contains some impurity or its hard to crystallize.

First of all check the melting point of your compound, if it is lesser than the room temperature then crystallize it in fridge.

Here are some techniques worth of trying; 1. the anti-solvent addition technique (solubilize the material in one solvent and add the other solvent in which the compound won't dissolve), 2. Solvent diffusion is another technique, here also you use two solvents but you do it in the very slow way 3. Quench your compound in liq. N2, 4. If your sample is soluble in alcohols then dissolve it and put it at high temperatures at around 40-45 C.

Good luck.

Hi Preethanuj,

If the problem is that the compound itself is liquid at RT, the obvious solution is to try to crystallize it in the freezer.

Also you can explore salt or cocrystal formation, which have been shown to work for this:

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