Pyrovus - 18-9-2006 at 03:21
For a while I've been toying with the idea of trying to react sodium fluoride with acetone, to see to what extent the fluoride ion will undergo
nucleophilic addition with the carbonyl carbon.
The hypothetical reaction should proceed as follows:
CH3COCH3 + NaF -> CH3C(F)(ONa)CH3
By acidifying, the fluorohydrin will be produced:
CH3C(F)(ONa)CH3 + H(+) -> CH3C(F)(OH)CH3
Going by the fact that the C-F bond is even stronger than the C-C bond, it should be very hard to break the C-F bond once formed, so the equilibrium
for the above reaction should lie mostly to the right.
The thing that has stopped me from trying this is that I'm worried about the toxicity of the product, should the reaction succeed. I've heard nothing
but horrible things said about fluorine compounds. I've tried googling every single conceivable synonym for acetone fluorohydrin, but have been unable
to find a MSDS for it. Without knowing how potentially toxic the stuff could be, there's no way I'll dare proceed.
unionised - 18-9-2006 at 11:48
NaF in acetone didn't kill these people- on the other hand it didn't seem to do anything very interesitng.
http://ajpcell.physiology.org/cgi/content/full/278/4/C718
For that reaction to work you need to break the NaF bond which is also pretty strong.
12AX7 - 18-9-2006 at 12:54
NaF + H2O <--> NaOH + HF?
HF doesn't dissociate well, but does NaF?
Tim
solo - 18-9-2006 at 19:45
Reference Information
Production, dissociation, and gas phase stability of sodium
fluoride cluster ions studied using electrospray ionization ion trap mass spectrometry
M.P. Ince, B.A. Perera, M.J. Van Stipdonk
International Journal of Mass Spectrometry 207 (2001) 41–55
Abstract
A Finnigan LCQ-Deca™ was used to produce and characterize ions derived from solutions of sodium fluoride. As with sputtering experiments involving
the same salt, electrospray produces an extensive series of positively charged cluster ions based on repeating units of NaF with a pendant Na cation.
In addition, a series of doubly charged ions corresponding to multiple (NaF) units modified by the addition of two Na cations was observed. We found
that the general peak intensity distribution in the mass spectrum of NaF was sensitive to the temperature of the heated capillary used in the LCQ to
desolvate ions after formation by electrospray ionization.
At temperatures greater than 200 °C the doubly charged ion signal disappears. At temperatures above 275 °C, a distribution of singly
charged cluster ions is produced that is similar to those observed in sputtering experiments conducted using sector or quadrupole based mass
spectrometers, including the increased intensities at well-known “magic numbers” that reflect the stability of structures reminiscent of the
solid-state structure of NaF. As in earlier investigations, our tandem mass spectromery experiments show that the preferred dissociation channel is
the loss of one or several (NaF) units and that the fragment ion intensities are influenced by the tendency to produce product ions with magic number
compositions. The doubly charged cluster ions “fission” to produce singly charged fragment ions in a process analogous to that shown for sodium
chloride cluster ions by Zhang and Cooks [Int. J. Mass Spectrom. 195/196 (2000) 667]. We found that the ion trap mass spectrometer is capable of
performing dissociation experiments up to and including MS
8 for most cluster ions with m/z values greater than 401. In addition, collision-induced dissociation profiles provide information about the relative
stability of inorganic cluster ions in the gas phase. For instance, we show for several cluster ions that the dissociation profiles and, in
particular, the shift in activation amplitude required for dissociation, are consistent with expected differences in stability due to the adoption of
magic number conformations.
Keywords: Electrospray ionization; Cluster ions; Collision-induced dissociation; Gas phase stability; Sodium fluorid
[Edited on 19-9-2006 by solo]
Attachment: Production dissociation and gas phase stabiluty of sodium .....pdf (288kB)
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