FOX-7

{{chembox

| Watchedfields = changed

| verifiedrevid = 441076766

| ImageFile = FOX7.png

| ImageSize = 150px

| PIN = 2,2-Dinitroethene-1,1-diamine

| OtherNames = FOX-7
FOX7

|Section1={{Chembox Identifiers

| CASNo_Ref = {{cascite|correct|??}}

| CASNo = 145250-81-3

| ChemSpiderID = 467536

| PubChem = 536770

| EC_number = 604-466-1

| UNII = 3B2KYV7C3F

| StdInChI = 1S/C2H4N4O4/c3-1(4)2(5(7)8)6(9)10/h3-4H2

| StdInChIKey = FUHQFAMVYDIUKL-UHFFFAOYSA-N

| SMILES = N/C(N)=C([N+]([O-])=O)\[N+]([O-])=O

}}

|Section2={{Chembox Properties

| Formula = C₂H₄N₄O₄

| MolarMass = 148.08

| Appearance = Bright yellow crystalline powder

| Density = 1.885 g cm⁻³

| MeltingPtC = 238

| MeltingPt_notes = (decomposes)

| BoilingPt =

| Solubility = Soluble in polar aprotic solvents such as dimethyl sulfoxide (DMSO), N,N-Dimethylformamide (DMF), and N-Methyl-2-pyrrolidone (NMP)

}}

|Section3={{Chembox Hazards

| MainHazards =

| FlashPt =

| AutoignitionPt =

| GHSPictograms = {{GHS01}}{{GHS02}}{{GHS07}}

| GHSSignalWord = Danger

| HPhrases = {{H-phrases|201|228|302}}

| PPhrases = {{P-phrases|210|230|240|241|250|264|270|280|301+312|330|370+378|370+380|372|373|401|501}}

}}

|Section6={{Chembox Explosive

| ShockSens =

| FrictionSens = >350N

| DetonationV = 8870 m/s at density 1.885 g cm⁻³ (estimated)
8335 m/s at density 1.756 g cm⁻³ (measured, small-scale testing)

| REFactor =

}}

}}

FOX-7 or 1,1-diamino-2,2-dinitroethylene (DADNE){{cite patent|country=US|status=patent|number=6340780|title=Method of preparing salts of dinitromethane|invent1=Nikolai Latypov|invent2=Ulf Wellmar|invent3=Abraham Langlet|assign=Swedish Defence Research Agency|gdate=2002-01-22}} is an insensitive high explosive compound. It was first synthesized in 1998 by the Swedish National Defence Research Institute (FOA).Bemm, U.; Östmark, H. (1998) "1,1-Diamino-2,2-dinitroethylene: a Novel Energetic Material with Infinite Layers in Two Dimensions". Acta Cryst C54: 1997-1999. {{doi|10.1107/S0108270198007987}}. According to other information it was synthesized in the USSR in 1990. The name FOX-7 is derived from the acronym of the Swedish Defence Research Agency (FOI), with the I replaced by an X to indicate an explosive, as in RDX and HMX.{{Citation|last1=Viswanath|first1=Dabir S.|title=FOX-7 (1,1-Diamino-2,2-Dinitroethylene)|date=2018|url=https://doi.org/10.1007/978-94-024-1201-7_3|work=Emerging Energetic Materials: Synthesis, Physicochemical, and Detonation Properties|pages=101–139 |place= Dordrecht|publisher=Springer Netherlands|doi=10.1007/978-94-024-1201-7_3|isbn=978-94-024-1199-7|access-date=2021-01-25|last2=Ghosh |first2=Tushar K.|last3=Boddu|first3=Veera M.}}

FOX-7 is similar to the insensitive chemical compound TATB, which is a benzene ring compound with three amino and three nitro groups.{{cite journal|doi=10.1016/j.tet.2005.05.010|title=The reactivity of 1,1-diamino-2,2-dinitroethene (FOX-7)|year=2005|last1=Hervé|first1=Grégoire|last2=Jacob|first2=Guy|last3=Latypov|first3=Nikolaj|journal=Tetrahedron|volume=61|issue=28|pages=6743}} FOX-7 has a two-carbon backbone rather than a benzene ring, but the amino and nitro groups have similar effects in both cases according to published reports on the sensitivity and chemical decay processes of FOX-7. FOX-7 is stoichiometrically identical (but structurally unrelated) to the explosives and propellants RDX and HMX, and therefore produces the same quantity of gas per gram, a key determinant of performance.{{cite journal|doi=10.1016/j.jhazmat.2006.03.034|title=Synthesis, characterization and thermolysis of 1,1-diamino-2,2-dinitroethylene (FOX-7) and its salts|year=2006|last1=Anniyappan|first1=M.|last2=Talawar|first2=M.B.|last3=Gore|first3=G.M.|last4= Venugopalan|first4=S.|last5=Gandhe|first5=B.R.|journal=Journal of Hazardous Materials|volume=137|issue=2|pages=812–9|pmid=16701943}}

By various measures, such as dropped-weight impact, friction force, temperature of ignition, and response to heating under confinement, it is less sensitive than the benchmark explosive RDX, while having performance slightly greater than the same.{{cite tech report |first=Lochert |last=Ian J. |title=FOX-7 - A New Insensitive Explosive |number=DSTO-TR-1238 |publisher=Defense Science & Technology Organization |publication-place=Fisherman's Bend, Victoria, Australia |date=November 2001 |url=https://apps.dtic.mil/dtic/tr/fulltext/u2/a399359.pdf |access-date=2021-01-25 |archive-date=2021-01-25 |archive-url=https://web.archive.org/web/20210125141310/https://apps.dtic.mil/dtic/tr/fulltext/u2/a399359.pdf |url-status=live }} Its explosive properties appear extremely favorable; in addition to its insensitive properties, the detonation velocity of mixtures of 80% FOX-7 plus binders is as high as Composition B, and nearly pure FOX-7 based plastic bonded explosives are slightly superior to RDX.{{Cite journal|last1=Latypov|first1=Nikolai V.|last2=Bergman|first2=Jan|last3=Langlet|first3=Abraham|last4=Wellmar|first4=Ulf|last5=Bemm |first5=Ulf|year=1998|title=Synthesis and reactions of 1,1-diamino-2,2-dinitroethylene|journal=Tetrahedron|volume=54|issue=38 |pages=11525–11536|doi=10.1016/s0040-4020(98)00673-5}} FOX-7 has been calculated to have a detonation velocity of 8,870 m/s.[http://www.intdetsymp.org/detsymp2002/PaperSubmit/FinalManuscript/pdf/Karlsson-165.pdf Detonation and Sensitivity Properties of FOX-7 and Formulations Containing FOX-7] {{Webarchive|url=https://web.archive.org/web/20050522150513/http://www.intdetsymp.org/detsymp2002/PaperSubmit/FinalManuscript/pdf/Karlsson-165.pdf |date=2005-05-22 }}, Karlsson et al., 2002, accessed Aug 25, 2005 Charges composed of EVA-coated FOX-7 granules pressed into pellets of 92% theoretical maximum density were found to have a detonation velocity of 7730 m/s, compared to 7630 m/s for a similar RDX/EVA composition, and 5% greater detonation pressure.

FOX-7 is produced as of 2018 by EURENCO Bofors AB of Sweden,{{cite tech report|last1=Sleadd|first1=Bradley A.|last2=Boruta|first2=David T.|last3=Clubb|first3=Joseph W.|title=Development of a CONUS manufacturing capability for FOX-7|institution=National Defense Industrial Association|date=24 April 2018|url=https://ndiastorage.blob.core.usgovcloudapi.net/ndia/2018/imem/20157_Sleadd_Presentation.pdf|access-date=25 January 2021|archive-date=25 January 2021|archive-url=https://web.archive.org/web/20210125141312/https://ndiastorage.blob.core.usgovcloudapi.net/ndia/2018/imem/20157_Sleadd_Presentation.pdf|url-status=live}} having been made in batches up to 7kg in 2001.{{cite conference|last1=Ostmark|first1=Henric|last2=Bergman|first2=Helena|last3=Bemm|first3=Ulf|last4=Goede|first4=Patrick|date=6 July 2001|title=Energetic Materials: Ignition, Combustion and Detonation|url=https://apps.dtic.mil/sti/citations/ADA396885|conference=32nd International Conference of ICT|publisher=Fraunhofer-Institut für Chemische Technologie|pages=26-1 - 26-21|archive-url= https://web.archive.org/web/20210125141313/https://apps.dtic.mil/sti/citations/ADA396885|archive-date=2021-01-25|place=Karlsruhe, Germany|book-title=2, 2-dinitro-ethene-1, 1-diamine(FOX-7)- Properties, analysis and scale-up|access-date=2021-01-25|url-status=live}} In laboratory-scale synthesis, material costs were calculated at ~AU$3000/kg (prices in 2002 AUD) using prices from research chemical suppliers. At that time, FOX-7 could be purchased from NEXPLO Bofors AB at SEK3200/kg. Due to its small-scale production, the cost of FOX-7 is relatively high. However, the production is based on commercial starting material and the synthesis is uncomplicated.{{cite patent|country=US|status=patent|number=6312538|title=Chemical compound suitable for use as an explosive, intermediate and method for preparing the compound|invent1=Nikolai Latypov|invent2=Ulf Wellmar|invent3=Abraham Langlet|assign=Swedish Defence Research Agency|gdate=2001-11-06}}

FOX-7 is an attractive subject for research and development due to its combination of insensitivity and power. FOX-7 performs similarly to RDX, one of the most powerful explosives and propellants in use, unlike other insensitive high explosives under investigation, such as TATB, nitrotriazolone, TEX, and 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105). Due to the need for less sensitive munitions, FOX-7 is being investigated at many military research centers, including in Australia, India, the USA, and Sweden.