Names | |
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Preferred IUPAC name
1,1′-Methylenedibenzene[1] | |
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 | |
Occupational safety and health (OHS/OSH): | |
Main hazards
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flammable |
Flash point | > 110 °C; 230 °F; 383 K |
Related compounds | |
Related compounds
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Diphenylmethanol |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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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.
Diphenylmethane is a common skeleton in organic chemistry. The diphenylmethyl group is also known as benzhydryl.
It is prepared by the Friedel–Crafts alkylation of benzyl chloride with benzene in the presence of a Lewis acid such as aluminium chloride:[2]
The methylene group in diphenylmethane is mildly acidic with a pKa of 32.2, and so can be deprotonated with sodium amide.[3]
The resulting carbanion can be alkylated. For example, treatment with n-bromobutane produces 1,1-diphenylpentane in 92% yield.[4]
Alkylation of various benzhydryl compounds has been demonstrated using the corresponding alkyl halides, both primary (benzyl chloride, β-phenylethyl chloride, and n-octyl bromide) and secondary (benzhydryl chloride, α-phenylethyl chloride, and isopropyl chloride), in yields between 86 and 99%.[3][4]
The acidity of the methylene group in diphenylmethane is due to the weakness of the (C6H5)2CH–H bond, which has a bond dissociation energy of 82 kcal mol−1 (340 kJ mol−1).[5] This is well below the published bond dissociation energies for comparable C–H bonds in propane, where BDE((CH3)2CH–H)=98.6 kcal mol−1, and toluene, where BDE(C6H5CH2–H)=89.7 kcal mol−1.[6][7]