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Author: Subject: How do I deal with an organic liquid that doesn't dissolve in certain other organic liquids?
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[*] posted on 5-3-2018 at 13:59
How do I deal with an organic liquid that doesn't dissolve in certain other organic liquids?

Hmm hmm, interesting. It makes perfect sense that it would dissolve in DCM, which is small enough to sneak into the nooks and crannies of many larger molecules (and has relatively polarized hydrogens for a 'non polar' solvent, giving it a stronger interaction with the nitrogen atom.)

Acetone might have a similar mechanism at work as far as how it dissolves your product (smaller molecule, some slightly polarized hydrogens due to the double-bonded oxygen atom pulling charge density towards itself.)

Not sure on the THF. At any rate, the product has a weakly polar nature, and the solvents that dissolved it have a weakly polar nature, so it fits the old logic of 'like dissolves like'. That water doesn't dissolve it makes perfect sense since the strength of the hydrogen bonds between water molecules will effectively push out/exclude large mostly non-polar molecules from solution. I'd be curious if it dissolves in aqueous acids (I'm guessing yes, but maybe not.)

Aluminium isopropoxide is a liquid at room temps (MW of 204), perhaps as a result of the shape limiting the amount of contact between the molecules (so there's less inter-molecule force holding them into fixed positions.) Maybe something similar is happening here?

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[*] posted on 5-3-2018 at 14:13

Not that i know jack shit, but "a high molecular weight secondary aniline to form a tertiary aniline" seems a bit vague.

Maybe if you stated the actual compounds ...

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[*] posted on 5-3-2018 at 15:59

Try yet more organic solvents. I have had plenty of compounds that are sparingly soluble in one solvent but highly soluble in another and when looking at those compounds and each solvent I am left scratching my head searching for a difference. Solvent selection is one of the key steps toward anything to do with chemistry as even choosing not to have a solvent is a choice in that regard. Hit it with everything you've got. Research. Then hit it with some more. Unless it's a polymer (and even they have their weaknesses) it's persistence that will payoff in the end.

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[*] posted on 5-3-2018 at 16:41

Did you delete your original post? I don't know what your product is or what solvents you have tried. Please edify me.

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[*] posted on 5-3-2018 at 18:19

Something that's insoluble in an alkane like hexane and also insoluble in water isn't surprising- most polar organic molecules will fit that description. Benzoic acid, for example- not really soluble in water (unless hot), not soluble in pentane or hexane, but perfectly soluble in alcohols, dichloromethane or ketones. Water's just too polar, and hexane's just too non-polar.

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