vinothan23
Harmless
Posts: 13
Registered: 8-7-2011
Member Is Offline
Mood: No Mood
|
|
Reaction of triethylamine with hydrogen fluoride
what is the reaction of HF with Triethyl amine in detail?
[Edited on 17-2-2012 by ScienceSquirrel]
|
|
|
simba
Hazard to Others
Posts: 175
Registered: 20-5-2011
Member Is Offline
Mood: No Mood
|
|
HF forms a fluroride salt with triethylamine. Acids form salts with amines.
|
|
|
BromicAcid
International Hazard
Posts: 3227
Registered: 13-7-2003
Location: Wisconsin
Member Is Offline
Mood: Rock n' Roll
|
|
Not that easy, triethylamine forms a number of salts with hydrogen fluoride, the most common of which that I run across is not the
(CH<sub>2</sub>CH<sub>3</sub> <sub>3</sub>N*HF
that you would expect but the trihydrofluoride salt (CH<sub>2</sub>CH<sub>3</sub><sub>3</sub>N*3HF which is commonly used in fluorinations or as a catalyst in fluorinations. As for the
detailed mechanism, not sure.
|
|
|
Hexavalent
International Hazard
Posts: 1564
Registered: 29-12-2011
Location: Wales, UK
Member Is Offline
Mood: Pericyclic
|
|
Should this not be in Beginnings?
"Success is going from failure to failure without loss of enthusiasm." Winston Churchill
|
|
|
ScienceSquirrel
|
Thread Moved
10-2-2012 at 16:32 |
ScienceSquirrel
International Hazard
Posts: 1863
Registered: 18-6-2008
Location: Brittany
Member Is Offline
Mood: Dogs are pets but cats are little furry humans with four feet and self determination! 
|
|
Honestly yes.
Hydrogen fluoride forms strong hydrogen bonds so it is to be expected that species like (Et)3N.3HF are formed.
|
|
|
Hexavalent
International Hazard
Posts: 1564
Registered: 29-12-2011
Location: Wales, UK
Member Is Offline
Mood: Pericyclic
|
|
Also, I would suggest adding a more descriptive title in the future . . .
"Success is going from failure to failure without loss of enthusiasm." Winston Churchill
|
|
|
arsphenamine
Hazard to Others
Posts: 236
Registered: 12-8-2010
Location: I smell horses, Maryland, USA
Member Is Offline
Mood: No Mood
|
|
Honestly, I don't understand.
SF<sub>6</sub> gives you d-orbital contributions to explain the hypervalence but no such orbitals are available with nitrogen.
Is this an instance of hyper<i>coordination</i> primarily due to HF species hydrogen bonding amongst themselves?
I'll model it, let you know if it's interesting.
|
|
|
ScienceSquirrel
International Hazard
Posts: 1863
Registered: 18-6-2008
Location: Brittany
Member Is Offline
Mood: Dogs are pets but cats are little furry humans with four feet and self determination!
|
|
Here is an interesting starting point;
http://benthamscience.com/open/tospecj/articles/V005/26TOSPE...
|
|
|
arsphenamine
Hazard to Others
Posts: 236
Registered: 12-8-2010
Location: I smell horses, Maryland, USA
Member Is Offline
Mood: No Mood
|
|
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.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
