Dear dear professors, researchers and colleagues
Would you please provide me, based on experience with any methods to grow single crystals of amine-copper complexes in DMF, DMSO ?
thank you in advance
ps: the amine ligands contain sulfur atom/atoms
A far more general answer. In view of the HSAB principle (Pearson) Cu(II) tends to be harder than you think. From my experience Cu(II) prefers N-donor ligands and DMF raedily coordinates to Cu(II). DMSO with it S-donor atom is far less preferred. For Cu(I) this is reversed.
Thus, recrystallising Cu(II) complexes from DMF is dangerous, since DMF might cleave and replace other ligands, while DMSO will probably not.
Mixing DMSO or DMF with alkanes is indeed tricky. Try mixtures of DMSO / heptane and Et2O like Fady proposed
that is a bit tricky.. try a vapour diffusion method using a THF/hexane or an Et2O/hexane solution (1/10)...DMF or DMSO are not miscible with hexane but when you add an ethereal solvent to that, all three become miscible and products crash out...
fill 1/4 of a vial with an almost saturated solution of the copper complex in DMF or DMSO. put the vial (leave the vial open) in a big container or a Schlenk and fill the container with the solution of THF/hexane (1/10) (or the same with Et2O/hexane) till the solution gets to the neck of the vial but not higher (be careful the vial don't fall or move, the two liquids need to stay separated). close the big container.. and let it sit still... try different batches with different dilutions of of the copper complex, and different low temperatures. if you use a more diluted solution of copper make sure to put the crystallisation flasks in the freezer, for lower temp trials. hope it helps.
A far more general answer. In view of the HSAB principle (Pearson) Cu(II) tends to be harder than you think. From my experience Cu(II) prefers N-donor ligands and DMF raedily coordinates to Cu(II). DMSO with it S-donor atom is far less preferred. For Cu(I) this is reversed.
Thus, recrystallising Cu(II) complexes from DMF is dangerous, since DMF might cleave and replace other ligands, while DMSO will probably not.
Mixing DMSO or DMF with alkanes is indeed tricky. Try mixtures of DMSO / heptane and Et2O like Fady proposed
@Axel_Klien
Thank you for all the good explanations
i will do
many thanks
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