Sciencemadness Discussion Board

Nitrogen Trifluoride

franklyn - 9-2-2007 at 06:31

Given that Trifluoramine is a stable gas even at elevated temperature and only about
as reactive as oxygen , it seems a likely candidate for sprengel type formulations , and
adducts by hydrogen bonding. Investigated for rocketry propellant applications, this has
current limited use as a chemical laser component but principly used industrially as a
fluorinating reagent and to etch silicon microcircuit chips.
http://pubs.acs.org/cgi-bin/abstract.cgi/jacsat/1960/82/i22/...
http://www.bocedwards.com/process_gases/pdf/nf3_a.pdf

NH3 + NF3 = 3HF + N2
C2H6 + 2NF3 = C2F6 + 3H2
B2H6 + 2NF3 = 2BF3 + 3H2
This has been investigated long ago in early work at Olin Matheson
http://stinet.dtic.mil/oai/oai?&verb=getRecord&metad...
and in earlier work at Aerojet General
http://rocketsciencebooks.home.att.net/liquids.html

Dangerously shock sensitive , dissolved in liquid boranes yields 4 times the energy of
Trinitrotoluene , detonation velocity is high in all cases but I find no available data.
B3N3H6 + 5 NF3 = 3 BF3 + 6 HF + 4 N2
2 B3N3H12 + 14 NF3 = 6 BF3 + 24 HF + 10 N2

Solid compounds with primary amine functional groups could serve as the host reducing
agent. Sodium amide , Hydroxylamine , Cyanamide , Urea , Guanidine , or their derivatives
come to mind but I have seen nothing reported.

A simple method of production without the need for elemental fluorine is by the
electrolysis of molten ammonium acid fluoride NH4F.HF , which produces nitrogen trifluoride
at the anode and hydrogen gas at the cathode ( Henderson & Woytek, 1994 )

http://ntp.niehs.nih.gov/ntp/htdocs/Chem_Background/ExSumPdf...
http://webbook.nist.gov/cgi/cbook.cgi?InChI=InChI%3D1/F3N/c1...
http://www.msgas.co.kr/english/msds/msds.asp?num=35

Important safety requirements for handling , read sections 6 and 7 _
http://www.airgas.com/documents/pdf/1079.pdf

Eenthalpy of formation and thermodynamic data of energetic compounds and fuels and oxidizers
http://www.dunnspace.com/isp.htm
http://cobweb.ecn.purdue.edu/~propulsi/propulsion/comb/prope...
http://srdata.nist.gov/cccbdb/hf0k.asp

.

quicksilver - 9-2-2007 at 07:16

I can only imagine the testing lab and the money involved in it's development! However it appears simpler to deal with elemental fluorine than to mfg molten ammonium acid fluoride by electrolysis. Is not the purpose to simplify as well as safely utilize enrgetic materials? Toxicity issues aside, the concept makes sense but appears much more complex than existing Sprengel type formulations or am I missing something? Is the Sprengel concept central to the invention or is it a means to utilize an energetic outside the existing ones?

not_important - 9-2-2007 at 07:48

Given that fluorine is made by electrolysis of molten acid fluorides, and the direct routes involve either the reaction of arc-excited N2 and F2 or F2 with NH3 in molten HNH4F2, I would think that simply electrolysis of HNH4F2 at 130 C would be no more difficult than those routes.

No matter what route is take, it will be tricky to do on any scale, toxic oxidisers can bite you in so many different ways.

franklyn - 9-2-2007 at 08:02

Bear in mind I am not a chemist, so that there may be myriad points evident
to an experienced experimenter that I am entirely oblivious of. My observation
is that there appears to be an absense of investigation into applications other
than what I mentioned , as a propellant oxidizer and chemical laser fuel.
Just as liquid oxygen makes a potent binary mixture with aluminum, so could
the cryogenic trifluoride, although not practical in safety or cost. Being a gas
it could I believe be absorbed in much the same way, for example as CO2 is by
an Alkali. Whether the resulting compound is stable enough to stand the stirring
required to assure saturation, is the only question I have.

.

JohnWW - 10-2-2007 at 14:27

What about use of it to make salts of NF4+? Does anyone know if NF5, which could exist only with two types of F atom, [NF4]+F-, and which would be detectable as such by F-19 NMR, has been made by anyone?