Dioxirane

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Not to be confused with Dioxane.
Dioxirane
Names
Preferred IUPAC name
Dioxirane
Systematic IUPAC name
Dioxacyclopropane
Other names
1,2-Dioxacyclopropane
Methylene peroxide
Peroxymethane
Identifiers
3D model (JSmol)
ChemSpider
  • InChI=1S/CH2O2/c1-2-3-1/h1H2 ☒N
    Key: ASQQEOXYFGEFKQ-UHFFFAOYSA-N ☒N
  • InChI=1/CH2O2/c1-2-3-1/h1H2
    Key: ASQQEOXYFGEFKQ-UHFFFAOYAK
  • C1OO1
Properties
CH2O2
Molar mass 46.03 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

In chemistry, dioxirane (systematically named dioxacyclopropane, also known as methylene peroxide or peroxymethane) is an organic compound with formula CH
2O
2. The molecule consists of a ring with one methylene and two oxygen atoms. It is of interest as the smallest cyclic organic peroxide, but otherwise it is of little practical value.

Synthesis

See also: Epoxidation with dioxiranes

Dioxirane is highly unstable and the majority of studies of it have been computational; it has been detected during the low temperature (–196 °C) reaction of ethylene and ozone,[1] although even at these temperatures such a mixture can be explosive.[2] Its formation is thought to be radical in nature, preceding via a Criegee intermediate. Microwave analysis has indicated C-H, C-O and O-O bond lengths of 1.090, 1.388 and 1.516 Å respectively.[2] The very long and weak O-O bond (c.f. hydrogen peroxide O-O = 1.47 Å) is the origin of its instability.

Other dioxiranes

Dioxiranes are derivatives of this parent in which the hydrogens are replaced by other groups. Difluorodioxirane, which boils at about –80 to –90 °C, is one of the very few dioxirane derivatives that is stable in pure form at room temperature and is thermodynamically stable (ΔH° = –104 kcal/mol).[3][4] Dimesityldioxirane is another relatively stable derivative which has been characterized by X-ray crystallography.[5]

Dimethyldioxirane (DMDO) and the still more reactive methyl(trifluoromethyl)dioxirane have seen some use in organic synthesis,[6] Dioxiranes are intermediate in the Shi epoxidation reaction.

See also

References

  1. ^ Lovas, F.J.; Suenram, R.D. (November 1977). "Identification of dioxirane (H2) in ozone-olefin reactions via microwave spectroscopy". Chemical Physics Letters. 51 (3): 453–456. Bibcode:1977CPL....51..453L. doi:10.1016/0009-2614(77)85398-0.
  2. ^ a b Suenram, R. D.; Lovas, F. J. (August 1978). "Dioxirane. Its synthesis, microwave spectrum, structure, and dipole moment". Journal of the American Chemical Society. 100 (16): 5117–5122. doi:10.1021/ja00484a034.
  3. ^ Kraka, Elfi; Konkoli, Zoran; Cremer, Dieter; Fowler, Joseph; Schaefer, Henry F. (1996-01-01). "Difluorodioxirane: An Unusual Cyclic Peroxide". Journal of the American Chemical Society. 118 (43): 10595–10608. doi:10.1021/ja961983w. ISSN 0002-7863.
  4. ^ Russo, Antonio; DesMarteau, Darryl D. (1993). "Difluorodioxirane". Angewandte Chemie International Edition in English. 32 (6): 905–907. doi:10.1002/anie.199309051. ISSN 0570-0833.
  5. ^ Sander, Wolfram; Schroeder, Kerstin; Muthusamy, Sengodagounder; Kirschfeld, Andreas; Kappert, Wilhelm; Boese, Roland; Kraka, Elfi; Sosa, Carlos; Cremer, Dieter (1997-08-01). "Dimesityldioxirane". Journal of the American Chemical Society. 119 (31): 7265–7270. doi:10.1021/ja964280n. ISSN 0002-7863.
  6. ^ Ruggero Curci; Anna Dinoi; Maria F. Rubino (1995). "Dioxirane oxidations: Taming the reactivity-selectivity principle" (PDF). Pure Appl. Chem. 67 (5): 811–822. doi:10.1351/pac199567050811. S2CID 44241053.
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