[Banny]

Can repulsive force work between fluorine and fluorine??
i know that fluorine likes fluorine.
and fluorine is hydrophobic and olephobic.

but,fluorine containing drug is didn`t loading fluorine containing amphiphilic polymer.

Why?.

[Hunter2]

The question is what else is in the drug. Probably more hydrophilic elements.

[orgopete]

Can repulsive force work between fluorine and fluorine??

Let me split thus into separate questions.
A) fluorine likes fluorine.
B) fluorine is hydrophobic and C) olephobic.

D) fluorine containing drug is didn`t loading fluorine containing amphiphilic polymer. (Huh?)

A) I'm not sure how this is concluded. I could think the opposite, but what are we comparing?

B) If you replace a methyl group with a fluorine, the result will be more water soluble. Compare ethane and fluoromethane. I am assuming hydrogen bonding, though a very weak force in this instance, may be occurring. You can find instances of intramolecular hydrogen bonding between a fluorine and an OH. Fluoride can be a very strong hydrogen bond acceptor. I would expect the properties of bound fluorine to be similar, but with a reduced intensity, similar to hydroxide and water. Water still hydrogen bonds, but not as strongly as hydroxide. I am thinking of how the properties of an electron pair can change, but it remains minus two.

I think if you take a polymer, it can also be hydrophobic as bulk water will be hydrogen bonded to water. If so, then water will be electrophobic, that is, it will demonstrate a greater Lewis base property than being an acid and base. If a fluoro polymer is surrounded by non-bonded electrons, then it too can be a Lewis base and repel the Lewis base properties of water.

C) This is a good question. I can think of instances that would support or negate a model for this. We could argue the hydrogens of borohydride are electron rich as it's reactions are as hydride donors. We might think the hydrogens of hydrocarbons can also be electron rich and repel the Lewis base properties of bound fluorines. That could explain why it might repel hydrocarbons. However, if you take a rubber balloon and rub it against wool or another oxygen rich substance, the balloon can pick off electrons. I might expect this property if a hydrocarbon had a generally positive surface.

D) I'm not sure I'm understanding this. From my experience, adding a fluorine can give two functions, block metabolism and increase water solubility. Water solubility was my main reason for using it. It can be difficult to adjust the lipophilicity of a compound without altering other properties. I think the popularity of flourine reflects its ability to achieve this need.