Dear Ahmed,

better to use anhydrous Fe salt for complexing with shiffbase ligand.

David,

The acidity of iron salt makes the bond prone to be cleaved especially with protic solvent around, thats why I mentioned using base.

Try using some aprotic solvent (DMSO, DMFA etc.) if it is suitable for your goals. Iron(III) salts are dissolved greatly in DMSO, however, the rate of dissolution is less than that in water.

Anhydrous Fe salts

Use of dry THF, dry DCM etc might work

If HCl evolution is a concern, you may use dry toluene

In the worst case scenario, the evolved HCl may protonate your ligand backbone (the imine)..

I know of instances where I have seen people use bases like LiHMDS...

Maybe the next time you could add some more detail to your question to help the community come up with better suggestions.

-best wishes.