I am facing difficulty to grow the crystals for my compounds (Heterocyclic compounds). Please suggest me the best method to grow the crystals.
If your organic compounds can be disolved in acetone or dichloromethane then try to used 1:1 acetone/hexane or dichloromethane/hexane solutions and allow a slow evaporation of the solution at RT or 6 °C, please insure that your compounds have been totaly dissolved in such systems
Best method to grow the crystals for organic Heterocyclic compd. is that first dissolve compd.in either ethyl acetate or acetonitrile or DMF by warming , allow to cool in freeze for 24 hrs. of more time . You will get the crystals.
check the solubility of the compounds in MeOH and Acetonitrile, if ur compound is soluble u will get crystal, if your compound is partially soluble or not, try in 1:1 mixture of (MeOH or ACN:Dichloromethane),
If possible add halogens to your molecules at the moment of synthesis choose derivatives with halogens. This will make crystallization very easy. The best method that works for me is to put 50-100 mg of each compound in small (5 mL) vials y dissolve in the minimum amount of organic polar solvent. In every vial try different solvent mixtures: 1) Ethyl acetate:hexanes (1:3), 2) DCM: Hexanes (1:3), 3) Acetonitrile:THF (1:3), etc. Basically depends in the solubility of your compound, for me methanol does not work very well. Then cover with parafilm the top of the vial and make small holes (2-6) with a needle and let it evaporate alone, do not touch it at least for one full day, then carefully check for crystals.
Also try solvents alone (EtOAc, Acetonitrile, etc). The more solvents and mixtures you try with halogenated compounds the more possibility one will crystallize.
although being a science crystal growing is much like knitting wool ... we need a lots of patience and ...lucky to find the right hand...good luck and do not give up
Hello, I agree with the comments made.... but what you need, and you are going to need a lot of it ..... Patience and also Luck.
One size does not fit all
First check is your compound is soluble in polar solvent then first make solution then make it concentrate by drying the polar solvent then add non polar solvent to the solution and also use some pure compound for overgrowth keep in refrigerator to crystallise i hope crystals will start to come with in 1 hour .
best of luck
You can try vapor diffusion method.. take your compound in polar solvent and keep this vial in another vial containing non-polar solvent.. seal it, keep it in a place with no disturbance and forget it for 2-3 days..or even week..
You can try different solvent combinations..and at both rt and 0-4oC..
The slow it grows chances are more to get the good crystal..
PATIENCE AND LUCK!!
Diffusion Method: Make in NMR cuvette the saturated solution of your Compounds in a suitable solvent. Insert the cuvette into the tube with a non-solvent and enclose / Seal by parafilm. Then be patient.
Dissolve in minimum amount of the solvent (ethanol, chloroform etc), and warm it, filter the warm solution, the filtrate allow to evaporate slowly..
Slow evaporation in a solvent in which it is soluble after gentle warming. Keep the solution aside without any disturbances until a crystal of required size is formed (Consult your crystallographer).
There is no a common method. Chem is try. So you should try, some milligrams are OK every time. Single solvent, or their mixed solvents should be used to cultivate single crystals. To keep slow evaporation or slow diffusion is very important.
Dear Devulapally,
As mentioned before, there is no single method that is guaranteed to work. If your attempts to crystallize your neutral heterocylce are unsuccesful, you might form a salt with a strong acid that might crystallize more easily. Some general information about the growth of single crystals can be found in our publication, a tutorial about the growth of single crystals: https://www.researchgate.net/publication/230751079_Some_thoughts_about_the_single_crystal_growth_of_small_molecules
Good luck!
Bernhard
Article Some thoughts about the single crystal growth of small molecules
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