Column chromatography using neutral alumina with 2-5% ethyl acetate in hexane can be used for lit

Dear Nqobile Ndlangamandla I just answered your question in a closely related thread. I assume that you followed a published literature procedure, right? If yes, I suggest to strictly follow this protocol. Salen-type Schiff bases are known since the 1930's and their synthesis and purification are normally quite straightforward. Generally you mix the respective ethylene diamine precursor with 2 equivalents of the unsubstituted or substituted salicylaldehyde in ethanol at room temperature. Then you heat the mixture to ca. 60 °C and let it stir at this temperature for ca. 4-6 hours. Evaporate the solvent under vacuum e.g. using a rotary evaporator. The desired ligand salen-type Schiff base ligand will then stay behind as a yellow solid. Further purification can normally be achieved by recystallization from ethanol or, as mentioned by Nayim Sepay by column chromatography. Normally, however, recrystallization should be sufficient.

I you could tell us a few more details about your particular Schiff base ligand, I can perhaps give you a more specific advice.

I hope this helps. Good luck with your work and best wishes, Frank Edelmann

Purifying Schiff base, dissolve Schiff base in DMF by heating , and cool slowly keeping overnight . The Schiff base will come out in the crystalline form.

In most of the cases, recrystallization is sufficient. Choice of the solvent depends on the solubility of the product.

The second alternative is to increase the reaction time and also optimize other conditions so as to ensure 100% conversion and finally wash the product with solvents in which the amine and aldehyde(if present) will dissolve. This methodology will provide a NMR spectrum corresponding only to the pure product.