DMF is a vital solvent to obtain single crystal metal-organic frameworks but it is hydrolysed in the presence of metal ions even at mild temprature (85 C) conditions.
How can somebody prevent it from hydrolysing?
Or, is the problem that even if the hydrolysis occured, how can one get rid of the hydrolysis products (formate ions) from the reaction media?
Thank you but, DMF widely use in organic synthesis as a solvent, due to its relatively high boiling point.
Are you saying that it is impossible to prevent the hydrolysis of DMF?
DMF will thermally decompose to give CO and dimethyl amine (presumably the method base is produced to deprotonate the ligands in MOF synthesis). This becomes more prominent at high temperatures. If you want to avoid formate formation then you need to keep your reaction media scrupulously dry. We do this by using DMF from a solvent purification system and then using proper Schlenk technique. I only observe formate salts after these reactions are left exposed to air (moisture).
What is the reason of heating up, When DMF is mixed with water.
hydrolysis ??? I was already preparing a DMF/water mixture.
in that case the hydrolysis takes place at that moment and what the reason of hydrolysis is not the high tempeture nor the solvothermal conditions.
Typically, reactions happen faster at elevated temperatures (as a rule of thumb, 2x faster for every 10 oC). Both of these reactions (thermal decomp. to give CO and dimethyl amine, and hydrolysis to give formates) will occur at room temperature, but become much faster at elevated temperatures. The DMF/water mixture that you are preparing will only produce formats very slowly at room temperature (this process is also acid or base catalyzed, so your reagents may play a non-innocent role), but occur faster at higher temperatures. As one of the other commenters suggested, you may be able to use other solvents for this prep, such as DMSO (which has also been used to prepare MOFs before), or you might try replacing the water with a dry alcohol.
Do we have the same problem with diethyl formamide? Which solvents are generally preferred for the synthesis of metal-organic polyhedra, since these are not polymeric..what are the poor solvents generally used in combination?
You can not avoid the hydrolysis since for the time beig both temperature and DMF cannot be avoided for material synthesis. DEF also hydrolises but because acetates are bigger than the formates in some cases may be more beneficial in small pore materials. But in general this is not the case for4 the materials researched. If it is such a huge thing and you have the formates or the dimethylamines interacting with the material and this is a bad thing for you, you might think of treaating the materials with an H donor... because i see you hate the formates formed....
Please is this problem also applicable to Dimethylacetamide? I am presently using it as a solvent for MOF synthesis and I am having problems getting the MOFs to form.
Are you sure that it is because of DMA? In that case just change the solvents for starters
The water-DMF mixing process is exothermic for all concentrations, with a maximum value of -0.5k cal/mol liberated at the concentration of 33% in DMF. The fact that this process is exothermic has been interpreted as a consequence of hydrogen bond formation between the carbonilic oxygen of the amide and the molecules of water, which have been confirmed by Raman spectroscopy. Calculations on the water-water and water-amide interaction energy have shown that hydrogen bonds between water and amides are stronger than between water molecules.
The source is a paper entitled "Study of Water and Dimethylformamide Interaction by Computer Simulation"
Please I want to know if DMF is hydrolyse when I use it as solvent to dissolve zinc acetate hydrate ,then this solution is added to solution of ligand in order to form complex.
Thank you Anthony Frank Cozzolino for your answer. Do we have any reports about this, so that it would be helpful for me cite the right article.
Dear, small revival of this topic, does DMF hydrolyse if it contains trace amount of ions and cations like zinc, copper, clhloride, manganese ?
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