zh 1,2-%E4%BA%8C%E5%99%81%E8%8B%B1

1,2-二噁英
	IUPAC名; 1,2-Dioxine; 1,2-二氧杂环己熳
	系统名; 1,2-Dioxacyclohexa-3,5-diene; 1,2-二氧杂环-3,5-己二烯
识别
CAS号	289-87-2
PubChem	15559065
ChemSpider	10606250
SMILES	O1OC=CC=C1;
InChI	1/C4H4O2/c1-2-4-6-5-3-1/h1-4H;
InChIKey	VCZQYTJRWNRPHF-UHFFFAOYAH
性质
化学式	C4H4O2
摩尔质量	84.07 g·mol−1
相关物质
相关化学品	二苯并对二噁英; 1,4-二噁英
	若非注明，所有数据均出自标准状态（25 ℃，100 kPa）下。

1,2-二噁英（英語：1,2-Dioxin）是一種杂环有机反芳香性^[1]化合物，化学式為C₄H₄O₂。它是1,4-二噁英的同分异构体。

由於它類似於过氧化物的性質，1,2-二噁英非常不穩定，仍未分離。根據計算，它會快速異構化成2-丁烯二醛。^[2]有取代基的衍生物也非常不穩定，例如1,4-二苯基-2,3-苯並二噁英。^[3]1990年，3,6-二(對甲苯基)-1,2-二噁英被誤認為是第一個穩定的衍生物，^[4]之後表明初始化合物不是1,2-二噁英的衍生物，而是一個熱力學上更穩定的二酮。^[5]

同分異構體1,2-二噁英（左）和1,4-二噁英（右）
不穩定的1,4-二苯基-2,3-苯並二噁英的結構
二噁英（1）和二酮形式（2）

參考文獻

^ Pelloni, Stefano; Faglioni, Francesco; Lazzeretti, Paolo. Parity violation energies of C4H4X2 molecules for X = O, S, Se, Te and Po. Molecular Physics. 2013-09-01, 111 (16-17): 2387–2391. ISSN 0026-8976. doi:10.1080/00268976.2013.794396.
^ Matsumoto, M. Product Class 1: 1,2-Dioxins and Benzo- and Dibenzo- Fused Derivatives. Science of Synthesis: Houben-Weyl Methods of Molecular Transformations Vol. 16: Six-Membered Hetarenes with Two Identical Heteroatoms. Georg Thieme Verlag. 2014: 13 [2020-06-12]. ISBN 9783131718815. （原始内容存档于2022-03-27）.
^ Smith, Jimmie P.; Schrock, Alan K.; Schuster, Gary B. Chemiluminescence of organic peroxides. Thermal generation of an o-xylylene peroxide. Journal of the American Chemical Society. 1982, 104 (4): 1041. doi:10.1021/ja00368a021. .
^ Shine, Henry J.; Zhao, Da Chuan. Electron transfer to excited doublet states. Photoirradiation of 10-methylphenothiazine cation radical perchlorate in solutions of phenylacetylene and p-tolylacetylene in acetonitrile. The Journal of Organic Chemistry. 1990, 55 (13): 4086. doi:10.1021/jo00300a026. .
^ Block, Eric; Shan, Zhixing; Glass, Richard S.; Fabian, Jürgen. Revised Structure of a Purported 1,2-Dioxin: A Combined Experimental and Theoretical Study. The Journal of Organic Chemistry. 2003, 68 (10): 4108–11. PMID 12737603. doi:10.1021/jo034305i.

[1] Pelloni, Stefano; Faglioni, Francesco; Lazzeretti, Paolo. Parity violation energies of C4H4X2 molecules for X = O, S, Se, Te and Po. Molecular Physics. 2013-09-01, 111 (16-17): 2387–2391. ISSN 0026-8976. doi:10.1080/00268976.2013.794396.

[2] Matsumoto, M. Product Class 1: 1,2-Dioxins and Benzo- and Dibenzo- Fused Derivatives. Science of Synthesis: Houben-Weyl Methods of Molecular Transformations Vol. 16: Six-Membered Hetarenes with Two Identical Heteroatoms. Georg Thieme Verlag. 2014: 13 [2020-06-12]. ISBN 9783131718815. （原始内容存档于2022-03-27）.

[3] Smith, Jimmie P.; Schrock, Alan K.; Schuster, Gary B. Chemiluminescence of organic peroxides. Thermal generation of an o-xylylene peroxide. Journal of the American Chemical Society. 1982, 104 (4): 1041. doi:10.1021/ja00368a021. .

[4] Shine, Henry J.; Zhao, Da Chuan. Electron transfer to excited doublet states. Photoirradiation of 10-methylphenothiazine cation radical perchlorate in solutions of phenylacetylene and p-tolylacetylene in acetonitrile. The Journal of Organic Chemistry. 1990, 55 (13): 4086. doi:10.1021/jo00300a026. .

[5] Block, Eric; Shan, Zhixing; Glass, Richard S.; Fabian, Jürgen. Revised Structure of a Purported 1,2-Dioxin: A Combined Experimental and Theoretical Study. The Journal of Organic Chemistry. 2003, 68 (10): 4108–11. PMID 12737603. doi:10.1021/jo034305i.

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