Sciencemadness Discussion Board - Reaction of triethylamine with hydrogen fluoride

Reaction of triethylamine with hydrogen fluoride

vinothan23 - 9-2-2012 at 19:51

what is the reaction of HF with Triethyl amine in detail?

[Edited on 17-2-2012 by ScienceSquirrel]

simba - 10-2-2012 at 09:50

HF forms a fluroride salt with triethylamine. Acids form salts with amines.

BromicAcid - 10-2-2012 at 10:43

Not that easy, triethylamine forms a number of salts with hydrogen fluoride, the most common of which that I run across is not the (CH2CH3

3N*HF that you would expect but the trihydrofluoride salt (CH2CH3

3N*3HF which is commonly used in fluorinations or as a catalyst in fluorinations. As for the detailed mechanism, not sure.

Hexavalent - 10-2-2012 at 16:17

Should this not be in Beginnings?

ScienceSquirrel - 10-2-2012 at 16:37

Honestly yes.
Hydrogen fluoride forms strong hydrogen bonds so it is to be expected that species like (Et)3N.3HF are formed.

Hexavalent - 17-2-2012 at 03:41

Also, I would suggest adding a more descriptive title in the future . . .

arsphenamine - 17-2-2012 at 17:20

Quote: Originally posted by ScienceSquirrel

Honestly yes.
Hydrogen fluoride forms strong hydrogen bonds so it is to be expected that species like (Et)3N.3HF are formed.

Honestly, I don't understand.

SF6 gives you d-orbital contributions to explain the hypervalence but no such orbitals are available with nitrogen.

Is this an instance of hypercoordination primarily due to HF species hydrogen bonding amongst themselves?

I'll model it, let you know if it's interesting.

ScienceSquirrel - 17-2-2012 at 17:53

Here is an interesting starting point;

http://benthamscience.com/open/tospecj/articles/V005/26TOSPE...

arsphenamine - 17-2-2012 at 20:09

Quote: Originally posted by ScienceSquirrel

Here is an interesting starting point;

http://benthamscience.com/open/tospecj/articles/005/26TOSPEC...

Thanks for the impressively pertinent reference.

I've had time to model the Et3N:3(HF) compd.

Semi-empirical methods (MOPAC, PM6) are extremely sensitive to the starting geometry, and no use other than for generating an input for ab initio methods.

Successively refined ab initio comps produce a geometry you'd expect if you focused on the H-bonds, but (perhaps fortuitously) give an N-H-F bond length of 2..586A in good accord with the 2.60A in Ilayaraja, et.al. NMR spin relaxation experimental methods.

GAMESS-US eq. geom. at the RHF/631G(2dp)** theory/basis set level were translated to Z-matrix format for Avogadro display and then exported to a .PNG image.

As expected, nitrogen is completely protonated.