Sciencemadness Discussion Board

Making Boron Triiodide

Triflic Acid - 17-3-2021 at 09:33

Can I make boron triiodide in situ, by combining iodine, boron, and a free radical initiator(like UV light). That would be much easier for me than heating it up. This is part of my quest to make alkyl iodides without phosphorus in a better yield than the Al I2 method, in this case using boron and iodide.

njl - 17-3-2021 at 09:49

What do you mean without heating it up?

RustyShackleford - 17-3-2021 at 10:26

Heating seems like a much simpler option than trying to get it solvated enough and blasting w uv

Triflic Acid - 17-3-2021 at 10:35

On Wikipedia it says: Boron triiodide can be prepared by the reaction of boron with iodine at 209.5 °C or 409.1 °F

Triflic Acid - 17-3-2021 at 11:56

One random thing, but, for methyl iodide, couldn't one do a finkelstein type reaction where an insoluble hydroxide precipitates out from the methanol solution?

njl - 17-3-2021 at 14:53

No because hydroxide is a far too basic leaving group for there to ever be any substitution. Plus whatever hydroxide you're thinking of would probably be somewhat soluble in methanol. This is pretty basic stuff you'll want to get down before messing with 80% of the stuff you post about.

draculic acid69 - 17-3-2021 at 15:54

You will also need 375grams of I2 for every ten grams of boron metal.do the math.
Do U want to spend that much $$$. And if making bx3's was easy everyone would do it
No chance imo of success without high temps

Triflic Acid - 17-3-2021 at 16:06

I was also doubtful that it work, (the methyl iodide and the boron triiodide both). But still, no harm in asking, because if it did that would be great :)