Nitric oxideのソースを表示

{{short description|Colorless gas with the formula NO}}
{{distinguish|nitrous oxide}}
{{About|a molecule of one nitrogen atom and one oxygen atom|other chemical combinations of nitrogen and oxygen|nitrogen oxide|the use of nitric oxide as a medication or in biology|Biological functions of nitric oxide}}
{{Chembox
| Verifiedfields = changed
| Watchedfields  = changed
| verifiedrevid  = 477001381
| Name           = 
| ImageFile      = Nitric-oxide-2D.svg
| ImageFile_Ref  = {{chemboximage|correct|??}}
| ImageSize      = 121
| ImageName      = Skeletal formula of nitric oxide with bond length
| ImageFileL1    = Nitric oxide.svg
| ImageNameL1    = Skeletal formula showing two lone pairs and one three-electron bond
| ImageFileR1    = Nitric-oxide-3D-vdW.png
| ImageFileR1_Ref = {{chemboximage|correct|??}}
| ImageNameR1    = Space-filling model of nitric oxide
| IUPACName      = Nitrogen monoxide<ref name="Nomenclature_2005" />
| SystematicName = Oxidonitrogen(•)<ref>{{cite web|title = Nitric Oxide (CHEBI:16480)|url = https://www.ebi.ac.uk/chebi/searchId.do?chebiId=16480|work = Chemical Entities of Biological Interest (ChEBI)|location = UK|publisher = European Bioinformatics Institute}}</ref> (additive)
| OtherNames     = Nitrogen oxide<br/>Nitrogen(II) oxide<br>Oxonitrogen
| Section1       = {{Chembox Identifiers
| IUPHAR_ligand = 2509
| CASNo = 10102-43-9
| ChEMBL_Ref = {{ebicite|changed|EBI}}
| ChEMBL = 1200689
| CASNo_Ref = {{cascite|correct|CAS}}
| PubChem = 145068
| ChemSpiderID = 127983
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| UNII = 31C4KY9ESH
| UNII_Ref = {{fdacite|correct|FDA}}
| EINECS = 233-271-0
| UNNumber = 1660
| DrugBank_Ref = {{drugbankcite|correct|drugbank}}
| DrugBank = DB00435
| KEGG = D00074
| KEGG_Ref = {{keggcite|correct|kegg}}
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 16480
| RTECS = QX0525000
| Gmelin = 451
| 3DMet = B00122

| SMILES = [N]=O
| StdInChI = 1S/NO/c1-2
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| InChI = 1/NO/c1-2
| StdInChIKey = MWUXSHHQAYIFBG-UHFFFAOYSA-N
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| InChIKey = MWUXSHHQAYIFBG-UHFFFAOYAI
}}
| Section2       = {{Chembox Properties
| N=1 | O=1
| Appearance = Colourless gas
| Density = 1.3402 g/L
| MeltingPtC = −164
| BoilingPtC = −152
| Solubility = 0.0098 g / 100&nbsp;ml (0&nbsp;°C) <br /> 0.0056&nbsp;g / 100&nbsp;ml (20&nbsp;°C)
| RefractIndex = 1.0002697
}}
| Section3       = {{Chembox Structure
| MolShape = linear ([[point group]] C<sub>∞''v''</sub>)
}}
| Section4       = 
| Section5       = {{Chembox Thermochemistry
| DeltaHf = 90.29 kJ/mol
| Entropy = 210.76 J/(K·mol)
}}
| Section6       = {{Chembox Pharmacology
| ATCCode_prefix = R07
| ATCCode_suffix = AX01
| Licence_EU=yes
| AdminRoutes = [[Inhalation]]
| Bioavail = good
| Metabolism = via pulmonary capillary bed
| HalfLife = 2–6 seconds
}}
| Section7       = {{Chembox Hazards
| ExternalSDS = [https://web.archive.org/web/20201102102334/https://www.boconline.co.uk/en/images/sg-088-nitric-oxide-v1.2_tcm410-39637.pdf External SDS]
| MainHazards = {{Unbulleted list
  | Fatal if inhaled
  | Causes severe burns
  | Causes eye damage
  | Corrosive to the respiratory tract}}<ref name="SDS">{{cite web| url=https://www.boconline.co.uk/en/images/sg-088-nitric-oxide-v1.2_tcm410-39637.pdf| title=Safety Data Sheet - Nitric Oxide, compressed - Registration Dossier| access-date=2020-11-02}}</ref>
| GHSPictograms = {{GHS04}}{{GHS03}}{{GHS05}}{{GHS06}}<ref name="ECHA">{{cite web| url=https://echa.europa.eu/registration-dossier/-/registered-dossier/24163/1| title=Nitrogen monoxide - Registration Dossier - ECHA| access-date=2020-11-02}}</ref><ref name=SDS/>
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|270|280|330|314}}<ref name=ECHA/><ref name=SDS/>
| PPhrases = {{P-phrases|244|260|220|280|304+340+315|303+361+353+315|305+351+338+315|370+376|403|405}}<ref name=ECHA/><ref name=SDS/>
| NFPA-H = 3
| NFPA-F = 0
| NFPA-R = 3
| NFPA-S = OX
| LC50 = 315&nbsp;ppm (rabbit, 15&nbsp;[[minute|min]])<br/>854&nbsp;ppm (rat, 4&nbsp;[[hour|h]])<br/>2500&nbsp;ppm (mouse, 12&nbsp;min)<ref name=IDLH>{{IDLH|10102439|Nitric oxide}}</ref>
| LCLo = 320&nbsp;ppm (mouse)<ref name=IDLH/>
}}
| Section8       = {{Chembox Related
| OtherFunction_label = nitrogen oxides
| OtherFunction = [[Dinitrogen pentoxide]]<br />
[[Dinitrogen tetroxide]]<br />
[[Dinitrogen trioxide]]<br />
[[Nitrogen dioxide]]<br />
[[Nitrous oxide]]<br/>
[[Azanone|Nitroxyl]] (reduced form)<br/>
[[Hydroxylamine]] (hydrogenated form)
}}
}}

'''Nitric oxide''' ('''nitrogen oxide''' or '''nitrogen monoxide'''<ref name="Nomenclature_2005">{{cite book |title=Nomenclature of Inorganic Chemistry, IUPAC Recommendations <!-- |title-link=IUPAC nomenclature of inorganic chemistry 2005 --> |url=http://old.iupac.org/publications/books/rbook/Red_Book_2005.pdf |publisher=International Union of Pure and Applied Chemistry |year=2005 |page=69}}</ref>) is a colorless gas with the formula '''{{chem|NO}}'''.  It is one of the principal [[oxides of nitrogen]]. Nitric oxide is a [[free radical]]: it has an [[unpaired electron]], which is sometimes denoted by a dot in its [[chemical formula]] (<sup>•</sup>N=O or <sup>•</sup>NO).  Nitric oxide is also a [[heteronuclear]] [[diatomic molecule]], a class of molecules whose study spawned early modern [[molecular orbital theory|theories of chemical bonding]].<ref name=G&E/>

An important [[Reaction intermediate|intermediate]] in [[chemical industry|industrial chemistry]], nitric oxide forms in combustion systems and can be generated by lightning in thunderstorms. In mammals, including humans, nitric oxide is a [[signaling molecule]] in many physiological and pathological processes.<ref>{{cite journal |pmid=10390607 |year=1999 |last1=Hou |first1=Y. C. |last2=Janczuk |first2=A. |last3=Wang |first3=P. G. |title=Current trends in the development of nitric oxide donors |volume=5 |issue=6 |pages=417–441 |journal=Current Pharmaceutical Design|doi=10.2174/138161280506230110111042 }}</ref>  It was proclaimed the "[[Molecule of the Year]]" in 1992.<ref name="pmid1361684">{{cite journal |author1=Culotta, Elizabeth  |author2=Koshland, Daniel E. Jr. | year = 1992 | title = NO news is good news | journal = Science | volume = 258 | issue = 5090 | pages = 1862–1864 | doi = 10.1126/science.1361684 | pmid = 1361684 |bibcode=1992Sci...258.1862C }}</ref>  The [[List of Nobel laureates in Physiology or Medicine#1951.E2.80.932000|1998 Nobel Prize in Physiology or Medicine]] was awarded for discovering nitric oxide's role as a cardiovascular signalling molecule.<ref>{{Cite web |title=The Nobel Prize in Physiology or Medicine 1998 |url=https://www.nobelprize.org/prizes/medicine/1998/summary/ |access-date=2022-06-17 |website=NobelPrize.org |language=en-US}}</ref>

Nitric oxide should not be confused with [[nitrogen dioxide]] (NO<sub>2</sub>), a brown gas and major [[air pollutant]], or with [[nitrous oxide]] (N<sub>2</sub>O), an [[general anaesthetic|anesthetic]] gas.<ref name="G&E"/>