Carbon disulfide is a nonpolar solvent (dielectric constant ε = 2.6, dipole moment µ =0). Therefore, it can extract well non/less polar compounds (BTEX) (hydrophobic interactions). DCM can also extract BTEX but not as well as CS2 because DCM is a less polar solvent (ε = 8.93, µ =1.55). The extraction capacity of acetone is the weakest because it is a polar solvent (ε = 20.7, µ = 2.85). I want to know if some other interactions and properties make CS2 and DCM extract BTEX well. Are there donor-acceptor interactions between BTEX and CS2/DCM/acetone as CS2/DCM/acetone is a lewis acid and BTEX is a lewis base?
Dear Nguyen Binh there is an old saying: "similia similibus solvuntur" which means that the best solvents are of similar chemical character. Thus non-polar CS2 is the best solvent for non-polar aromatic hydrocarbons. I would not call CS2, DCM and acetone Lewis acids as in your original question. All three of them have non-bonding pairs of electrons and could also act as Lewis bases.
Besides, researchers today try to replace CS2 as a solvent for extraction of BTEX because of its significant toxicity and very high flammability. In this context dichloromethane (DCM) is clearly the better choice. For a good article in which the different solvents are compared please have a look at the following link:
An improved method for BTEX extraction from charcoal
https://pubs.rsc.org/no/content/getauthorversionpdf/C5AY00828J
In the Introduction section of this article the pros and cons of CS2 and DCM are discussed.
Good luck with your work!
Dear Frank T. Edelmann Thank you so much for your kind reply and contributions.
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