// Workers AI · dad joke modeWhat did Dimesityldioxirane say? "I'm an oxide above the rest.
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| Names | |
|---|---|
| IUPAC name
3,3-bis(2,4,6-trimethylphenyl)dioxirane | |
| Identifiers | |
3D model (JSmol) |
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| ChemSpider | |
PubChem CID |
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| Properties[1][2] | |
| C19H22O2 | |
| Molar mass | 282.4 g/mol |
| Density | 1.180 g/cm3 (calculated, 173 K) |
| Melting point | 62–64 °C (144–147 °F; 335–337 K) (partial decomp.) |
| Solubility | Soluble in trichlorofluoromethane, carbon tetrachloride, chloroform, methanol |
| Structure[2] | |
| Orthorhombic, oP | |
| Pbca, No. 61 | |
a = 15.970 Å, b = 7.956 Å, c = 25.018 Å (at 173 K) | |
Lattice volume (V) |
3178.7 Å3 |
Formula units (Z) |
8 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Dimesityldioxirane is a substituted dioxirane with two mesityl groups attached to the dioxirane carbon. It is a colorless crystalline substance, indefinitely stable at −20 °C.
Structure
[edit]In the solid phase, the molecule possesses approximate C2 symmetry; under B3LYP this is predicted to be an exact symmetry, with each mesityl group being twisted away from coplanarity by 54.2°. The bulky mesityl groups cause steric strain, which is compensated for by an increase in the R1–C–R2 angle from 117° in dioxirane to 119.2° in dimesityldioxirane, together with rotation of the mesityl groups out of plane. This in turn yields a narrower O–C–O angle and a shorter and stronger O–O bond than in other dioxiranes, stabilizing the molecule.[1]
Synthesis
[edit]Dimesityldioxirane was first isolated at room temperature in pure as well as in solution form in 1994.[3] It was synthesised by irradiation of dimesityldiazomethane, its diazo derivative, in oxygen-saturated trichlorofluoromethane at 183 K to form dimesitylcarbene, which reacts to form dimesityldioxirane via a carbonyl oxide intermediate, with overall yield 50%.[4]
Stability
[edit]Pure dimesityldioxirane is indefinitely stable at −20 °C in the absence of light, in both solid form and trichlorofluoromethane solution. Upon exposure to blue light, it undergoes photolysis to mesityl 2,4,6-trimethylbenzoate. In solid form at room temperature, it decomposes over a period of weeks to dimesitylketone and mesityl 2,4,6-trimethylbenzoate.[1] In methanol solution at room temperature, it decomposes over a period of hours to days, while also slowly oxidizing the solvent.[1]
Reactions
[edit]Like other dioxiranes, it is a potent oxygen-transfer reagent, driving characteristic reactions such as the epoxidation of cyclohexene.[1]
See also
[edit]References
[edit]- 1 2 3 4 5 Sander, Wolfram; Schroeder, Kerstin; Muthusamy, Sengodagounder; Kirschfeld, Andreas; Kappert, Wilhelm; Boese, Roland; Kraka, Elfi; Sosa, Carlos; Cremer, Dieter (1997-08-01). "Dimesityldioxirane" (PDF). Journal of the American Chemical Society. 119 (31): 7265–7270. doi:10.1021/ja964280n. ISSN 0002-7863.
- 1 2 Sander, Wolfram; Schroeder, Kerstin; Muthusamy, Sengodagounder; Kirschfeld, Andreas; Kappert, Wilhelm; Boese, Roland; Kraka, Elfi; Sosa, Carlos; Cremer, Dieter (1997-08-01). "Dimesityldioxirane (Supplementary Material)". Journal of the American Chemical Society. 119 (31): 7265–7270. doi:10.1021/ja964280n. ISSN 0002-7863.
- ↑ Walton, Lesley (1996-01-01). Epoxidation using dioxiranes (PhD thesis). Loughborough University.
- ↑ Kirschfeld, Andreas; Muthusamy, Sengodagounder; Sander, Wolfram [in German] (1994-11-17). "Dimesityldioxirane—A Dioxirane Stable in the Solid State". Angewandte Chemie International Edition in English. 33 (21): 2212–2214. doi:10.1002/anie.199422121. ISSN 0570-0833.