Definition
Diphenylmethane is an organic compound with the formula (C6H5)2CH2 (often abbreviated CH2Ph2). The compound consists of methane wherein two hydrogen atoms are replaced by two phenyl groups. Diphenylmethane is a common skeleton in organic chemistry. The diphenylmethyl group is also known as benzhydryl, and it is prepared by the Friedel–Crafts alkylation of benzyl chloride with benzene in the presence of a Lewis acid such as aluminium chloride.
Uses
Diphenylmethane is widely used in the synthesis of luminogens for aggregation-induced emission (AIE).
It is used in the preparation of a polymerization initiator, diphenylmethyl potassium (DPMK).
It is one of the precursors in the synthesis of a dendrimeric polycyclic aromatic hydrocarbon (PAH), hexakis[4-(1,1,2-triphenyl-ethenyl)phenyl]benzene.
Application
The main application of diphenylmethane includes widely used in the synthesis of luminogens for aggregation-induced emission (AIE) and used in the preparation of a polymerization initiator, diphenylmethyl potassium (DPMK). It is one of the precursors in the synthesis of a dendrimeric polycyclic aromatic hydrocarbon (PAH), hexakis [4-(1,1,2-triphenyl-ethenyl) phenyl] benzene.
Synthesis
The classical synthesis of Diphenylmethane (DPMK) is the indirect metallation via potassium naphthenide. n-Butyllithium (n-BuLi) solution (1.6 M in hexanes) and sec-butyllithium (sec-BuLi) solution (1.4 M in cyclohexane) were diluted and ampoulized on a high vacuum line. Lithium chloride (99.999%, LiCl,) was dried at 130 °C for 2 days and then diluted to the target concentration in THF and ampoulized under a reduced pressure of 10-6 mm Hg. Sodium (NaNaph) and potassium naphthalenide (K-Naph) were prepared by the reaction of the corresponding metal with naphthalene in THF at room temperature for 48 h. Diphenyl methyl potassium (DPMK) was prepared by the reaction of K-Naph with diphenylmethane in THF under high vacuum conditions at room temperature for 72 h. The concentration of DPMK was determined by titration using octyl alcohol and used for anionic polymerization. All initiators were sealed off under high vacuum into ampoules with break seals and stored at -30 °C.
Chemical Properties
Colorless to pale yellow low melting solid
Occurrence
Has apparently not been reported to occur in nature.
Uses
Diphenylmethane, is used as an adhesive chemical composition for making flexible laminates for use in food packaging.
Preparation
By interaction of benzyl chloride and benzene in the presence of an acid cata lyst.
Definition
ChEBI: A diarylmethane that is methane substituted by two phenyl groups.
Metabolism
Diphenylmethane is hydroxylated in the rabbit and some 15% of the dose is excreted as 4-hydroxydiphenylmethane, which is largely (80-90%) in the free state. Neither the hydrocarbon nor its metabolite is oestrogenic. This reaction also occurs in the dog (Williams, 1959).
Purification Methods
Sublime it under vacuum, or distil it at 72-75o/0.4mm. Recrystallise it from cold EtOH. It has also been purified by fractional crystallisation from the melt. [Armarego Aust J Chem 13 95 1960, Beilstein 5 II 498, 5 IV 1841.]
