Diphenylmethane
Diphenylmethane is an organic compound with the formula (C6H5)2CH2 (often abbreviated CH
2Ph
2). The compound consists of methane wherein two hydrogen atoms are replaced by two phenyl groups. It is a white solid.
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| Names | |
|---|---|
| Preferred IUPAC name
1,1'-Methylenedibenzene | |
| Other names
Diphenylmethane Benzylbenzene | |
| Identifiers | |
3D model (JSmol) |
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| Abbreviations | BnPh, Ph2CH2 |
| ChEBI | |
| ChEMBL | |
| ChemSpider | |
| ECHA InfoCard | 100.002.708  |
| MeSH | Diphenylmethane |
PubChem CID |
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| UNII | |
CompTox Dashboard (EPA) |
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| Properties | |
| C13H12 | |
| Molar mass | 168.234 |
| Appearance | colourless oil |
| Density | 1.006 g/mL |
| Melting point | 22 to 24 °C (72 to 75 °F; 295 to 297 K) |
| Boiling point | 264 °C (507 °F; 537 K) |
| 14 mg/L | |
| Acidity (pKa) | 33 |
| -115.7·10−6 cm3/mol | |
| Hazards | |
| Main hazards | flammable |
| Flash point | > 110 °C; 230 °F; 383 K |
| Related compounds | |
Related compounds |
Diphenylmethanol |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
 verify (what is  ?) | |
| Infobox references | |
Diphenylmethane is a common skeleton in organic chemistry. The diphenylmethyl group is also known as benzhydryl.
Synthesis
It is prepared by the Friedel–Crafts alkylation of benzyl chloride with benzene in the presence of a Lewis acid such as aluminium chloride:[1]
- C6H5CH2Cl + C6H6 → (C6H5)2CH2 + HCl
Reactivity of the C-H bond
The methylene group in diphenylmethane is mildly acidic with a pKa of 32.2. The resulting carbanion can be alkylated:[2]
- (C6H5)2CH2 + NaNH2 → (C6H5)2CHNa + NH3
- (C6H5)2CHNa + RBr → (C6H5)2CHR + NaBr
The Ph2CH-H bond is weak, with a bond dissociation energy of 82 kcal/mol.[3]
References
- W. W. Hartman and Ross Phillips (1934). "Diphenylmethane". Organic Syntheses. 14: 34. doi:10.15227/orgsyn.014.0034.
- Murphy, William S.; Hamrick, Phillip J.; Hauser, Charles R. (1968). "1,1-Diphenylpentane". Organic Syntheses. 48: 80. doi:10.15227/orgsyn.048.0080.
- . doi:10.1021/ja00051a010. Cite journal requires
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