Nitrosobenzene
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| Nitrosobenzene | |
|---|---|
 |
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| General | |
| Systematic name | Nitrosobenzene |
| Other names | ? |
| Molecular formula | C6H5NO |
| SMILES | O=Nc1ccccc1 |
| Molar mass | 107.11 g/mol |
| Appearance | colourless solid |
| CAS number | [586-96-9] |
| Properties | |
| Density and phase | ? g/cm3, ? |
| Solubility in water | low |
| Other solvents | sol. in organic solvents |
| Melting point | 65-69 °C |
| Boiling point | 59 °C, 18 mm Hg |
| Acidity (pKa) | ? |
| Viscosity | ? cP at ? °C |
| Structure | |
| Molecular shape | N is sp2 |
| Dipole moment | ? D |
| Hazards | |
| MSDS | External MSDS |
| Main hazards | toxic |
| NFPA 704 | |
| Flash point | ? °C |
| R/S statement | R: 20/21-25 S: 26-36/37-45 |
| RTECS number | DA6497525 |
| Supplementary data page | |
| Structure and properties |
n, εr, etc. |
| Thermodynamic data |
Phase behaviour Solid, liquid, gas |
| Spectral data | UV, IR, NMR, MS |
| Related compounds | |
| Related Nitroso compounds | ? |
| Related compounds | Nitrobenzene Aniline |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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Nitrosobenzene is the organic compound C6H5NO. The compound can be viewed as hybrid of singlet O2 and azobenzene. This diamagnetic species exists in equilibrium with its dimer.
Contents |
[edit] Preparation
C6H5NO was first reported by Adolf Baeyer in 1874,[1] who prepared it by the reaction of diphenylmercury and nitrosylbromide, "Bringt man eine Loesung von NOBr in Benzol in eine Loesung von Quecksilberphenyl in Benzol …"
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- [C6H5]2Hg + BrNO → C6H5NO + C6H5HgBr
The modern synthesis entails reduction of nitrobenzene to phenylhydroxylamine, C6H5NHOH, which is then oxidized by Na2Cr2O7.[2] C6H5NO was also prepared by Caro via oxidation of aniline using peroxymonosulfuric acid, Caro's acid.[3] It is usually purified by steam distillation, where it comes over as a green liquid that solidifes to a colorless solid.
[edit] Characteristic reactions
The monomer undergoes Diels-Alder reactions with dienes.[4] Most characteristically nitrosobenzene condenses with "active" methylene and amine groups, e.g. of malonic esters. Condensation with anilines affords azobenzene derivatives (Mills reaction).[5][6]
Reduction of PhNO produces C6H5NH2.
[edit] See also
[edit] References
- ^ Baeyer, A. "Nitrosobenzol und Nitrosonaphtalin" Chemische Berichte 1874, volume 7, pp.1638–1640.
- ^ G. H. Coleman, C. M. McCloskey, F. A. Stuart "Nitrosobenzene" Organic Syntheses, Collected Volume 3, p.668. http://www.orgsyn.org/orgsyn/pdfs/CV3P0668.pdf
- ^ H. Caro, Z. angew. Chem., volume 11, p 845ff (1898).
- ^ H. Yamamoto, N. Momiyama "Rich Chemistry of Nitroso Compounds" Chemical Communications 2005, pp.3514–3525.
- ^ H. Feuer in S. Patai (ed.) "The Chemistry of the Nitro and Nitroso Groups Part 1," Wiley: New York. pp. 278-283 (Mills reaction)
- ^ *H. D. Anspon, p-Phenylazobenzoic Acid" Organic Syntheses, Collected Volume 3, p.711. http://www.orgsyn.org/orgsyn/pdfs/CV3P0711.pdf
