Diphenyl-methane

From this value and known C—H bond dissociation energies, pK values can be calculated. Early application of these methods gave estimates of the p/Ts of toluene and propene of about 45 and 48, respectively. Methane was estimated to have a pAT in the range of 52-62. Electrochemical measurements in DMF have given the results shown in Table 7.3. These measurements put the pK of methane at about 48, with benzylic and allylic stabilization leading to values of 39 and 38 for toluene and propene, respectively. The electrochemical values overlap with the pATdmso scale for compounds such as diphenyl-methane and triphenylmethane. 

Several high-boiling, inert solvents have been reported in various steps of the Gould-Jacobs reaction. Dowtherm, f Ph20, cumene, tetraglyme, diphenyl methane, ... 

Polynitrodiphenylmethanes. See Diphenyl-methane and Derivatives in Vol 5, D1464-L to D1466-L. Hexanitrodiphenylmethane had not been synthesized as of 1966. However, since then the work of Shipp and Kaplan (Ref 2) in 1976 allows the following entry to be made ... 

Methane, nitio-, 55, 78 Methane, tnphenyl, 55,11 Methanesulfonyl chlonde, 55, 116, 120 Methyl chlonde, diphenyl- [Methane, chlo-rodiphenyl-], 55 94 Methyl ether, chloromethyl- [Methane, chloro-methoxy-], 55,94... 

Lithiumalanat in siedendem Bis-[2-methoxy-athyl]-ather reduziert 1,1-Diaryl-athylene bei gleichzeitiger Me-thylierung durch das Losungsmittel5 (Diphenyl-methan-Derivate werden ebenfalls methyliert6). Natrium-bis-[2-methoxy-athoxy]-aluminiumhydrid reduziert und methyliert selbst 1,1-Diphenyl-athylen (in Kohlenwasser-stoff-Losung)7 und Arene8. 

Benzylchlorid 1-Chlor- l-phenyl-athan Chlor-diphenyl-methan Dichlor-phcnyl-mcthan D ichlor- diphenyl- methan 3-Chlor-2-methyl-propen... 

Diphenyl-diazomethan liefert bei der Elektrolyse an Platin in DMF/Tetrabutylammo-niumperchlorat Diphenylmethan, Amino-diphenyl-methan und Benzophenon-azin. Bei hohcn negativen Potentialen (—1,9 bis —2,2 V) und niedriger Ausgangskonzentration iiberwiegt Diphenylmethan (bis 51% d.Th.) das Azin dominiert erwartungsgemaB bei... 

The reaction has not been elucidated. Presumably Michler s thioketone reacts with organomercury compounds to yield intensely colored, mesomer-stabilized diphenyl-methane derivatives. 

Rigid polyurethane foams were prepared at room temperature using eommercial polyols and polymerie 4,4 -diphenyl methane diisoeyanate, and used to study their reeyeling by aminolysis. The reaction products obtained by treatment with diethylene triamine at 180 C were evaluated as hardeners for epoxy resins. The exothermie heats of euring were determined over the temperature range 60-80 C by differential scanning calorimetry. A reaction order of 2.2-2.4 was obtained. 8 refs. 

NR can be cross-linked by a blocked diphenyl methanes diisocyanate to produce urethane crosslinks. The cross-linking agent dissociates into two quinonedioxime molecules and one diphenyl methane diisocyanate. The quinone reacts with the rubber via a nitroso group and forms cross-links via diisocyanato group. The performance of this system in NR is characterized by excellent age resistance and outstanding reversion resistance. 

PCBs and PCTs are particularly troublesome liquids because of their toxicity and persistence in the environment. They are defined as polychlorinated biphenyls, polychlorinated terphenyls, monomethyl-dibromo-diphenyl methane, monomethyl-dichloro-diphenyl methane or monomethyl-tetrachlorodiphenyl methane. With low electrical conductivity and heat resistance they found wide use as dielectric fluids and were formerly used as hydraulic fluids. PCBs have not been made in the UK since 1977 and whilst most new uses for the substance are banned in most countries, around two-thirds of the 1.5 million tonnes manufactured in Europe and the US prior to 1985 still remain in equipment such as transformers. PCTs have been used in the past in a restricted range of specialist industrial applications. 

Use of benzotriazole in the preparation of diphenylmethanes and triphenylmethanes has been reviewed." Benzotriazole is condensed with an aldehyde and then allowed to react with naphthols to form a diphenyl-methane benzotriazole derivative such as 69 (Scheme 9). The benzotriazole moiety in 69 is displaced by a Grignard reagent to give triphenylmethanes.79 100 This method allows for the preparation of triarylmethanes which contain three different aromatic rings. Compounds 70-72 are prepared by this method. 

Phenolic compounds were confirmed to be very stable against thermal treatment. Diphenyl methanol and benzophenone were stable against decomposition but hydrogenated to form diphenyl -methane quantitatively. Phenyl benzyl ketone was found to be partially hydrogenated or decarbonylated to form diphenyl alkanes. 

There are no clear advantages in terms of functional performance between the two classes of dyes, except that phthalocyanines are generally more light stable but tend to be more expensive to synthesize and modify. Phthalocyanine dyes are not suitable for DVD-R media, since the main chromophore cannot readily be modified to produce a sufficiently large hypsochromic shift. Other dyes potentially suitable for DVD-R include metal azo complexes, quinophthalones, and diphenyl-methanes. The cyanine dyes are particularly useful as they can be readily modified to tailor the optical absorbance requirements for all current optical disk recording applications.199... 

Table 6.15 shows the product mixture from an unstirred (silent) reaction in which the only mixing is by convection, an arrangement not normally used in electrosynthesis. (All electrosyntheses are normally agitated mechanically in some way and therefore still conditions cannot practically be achieved.) For these conditions, the major product was the isomeric mixture of diphenyl methane derivatives. This was similiar to the product mix obtained at 800 kHz. Thus the use of high frequency ultrasound... 

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