Dinitrogen trioxide 728908 218093170 2008-06-09T03:17:07Z Escarbot 1554195 robot Adding: [[ko:삼산화 이질소]] [r5540] {{Chembox new | Name = Dinitrogen trioxide | ImageFile = Dinitrogen-trioxide-3D-vdW.png | ImageSize = 200px | ImageFile1 = Dinitrogen-trioxide-xtal-3D-vdW.png | ImageName = Dinitrogen trioxide | Section1 = {{Chembox Identifiers | CASNo = 10544-73-7 }} | Section2 = {{Chembox Properties | Formula = N<sub>2</sub>O<sub>3</sub> | MolarMass = 76.01 | Appearance = blue liquid | Density = 1.4 × 10<sup>3</sup> kg m<sup>−3</sup>, liquid | MeltingPt = −100.1°C (173.05 K) | BoilingPt = 3°C (276 K) }}<!-- {{Chembox/DeltaHf298|+91.20}} {{Chembox/S298|314.63}} --> | Section7 = {{Chembox Hazards | EUClass = Highly toxic ('''T+''') | NFPA-H = 3 | NFPA-F = | NFPA-R = | NFPA-O = OX | RPhrases = {{R26}}, {{R34}} | SPhrases = {{S1/2}}, {{S9}}, {{S26}}, {{S28}},<br />{{S36/37/39}}, {{S45}} }} }} '''Dinitrogen trioxide''' is the [[chemical compound]] with the [[chemical formula|formula]] N<sub>2</sub>O<sub>3</sub>. This deep blue [[liquid]] is one of binary [[nitrogen oxide]]s. It forms upon mixing equal parts of [[nitric oxide]] and [[nitrogen dioxide]] and cooling the mixture below −21°C (−6°F): :NO + NO<sub>2</sub> <math>\overrightarrow{\leftarrow}</math> N<sub>2</sub>O<sub>3</sub> Dinitrogen trioxide is only isolable at low temperatures, i.e. in the liquid and solid [[phase (matter)|phases]]. At higher temperatures the equilibrium favors the constituent gases. K<sub>diss</sub> = 193 kPa (25 °C).<ref>Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.</ref> ==Structure and bonding== Dinitrogen trioxide has an unusually long N−N bond at 186 [[1 E-12 m|pm]]. Whereas N−N bonds are more often similar to that in [[hydrazine]] (145 pm), some other [[Nitrogen oxide|oxides of nitrogen]] do possess long N−N bonds, including [[dinitrogen tetroxide]] (175 pm). The N<sub>2</sub>O<sub>3</sub> molecule is planar and exhibits ''C<sub>s</sub>'' symmetry. The dimensions displayed below come from microwave spectroscopy of low-temperature, gaseous N<sub>2</sub>O<sub>3</sub>: [[Image:Dinitrogen-trioxide-2D-geometry.png|400px|center|The bond lengths and angles of dinitrogen trioxide]] It is the [[anhydride]] of the unstable [[nitrous acid]] (HNO<sub>2</sub>), and produces it when mixed into water. An alternative structure might be anticipated for the true anhydride, i.e. O=N-O-N=O, but this isomer is not observed. If the nitrous acid is not then used up quickly, it decomposes into [[nitric oxide]] and [[nitric acid]]. [[Nitrite]] [[salt]]s are sometimes produced by adding N<sub>2</sub>O<sub>3</sub> to solutions of bases: :N<sub>2</sub>O<sub>3</sub> + 2 NaOH → 2 NaN<sub></sub>O<sub>2</sub> + H2O Nitrogen Trioxide = NO3 ==References== <references/> ==External links== *[http://www.npi.gov.au/database/substance-info/profiles/67.html National Pollutant Inventory - Oxides of nitrogen fact sheet] * [http://www.webelements.com/webelements/compounds/text/N/N2O3-10544737.html Webelements: Compound data - dinitrogen trioxide] * [http://www.c-f-c.com/supportdocs/nitrogen_oxi.htm Oxides of nitrogen - synthesis and uses] * [http://www.chem.msu.su/rus/handbook/ivtan/79.html Ivtantermo - dinitrogen trioxide table of values] [[Category:Oxides]] [[Category:Nitrogen compounds]] [[Category:Acidic oxides]] [[cs:Oxid dusitý]] [[da:Dinitrogentrioxid]] [[de:Distickstofftrioxid]] [[es:Óxido de nitrógeno (III)]] [[ko:삼산화 이질소]] [[ja:三酸化二窒素]] [[pl:Tritlenek diazotu]] [[ru:Оксид азота(III)]] [[zh:三氧化二氮]]