Diphenyl alkanes

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. 

The high molecular weight fractions from LAB manufacture can also be used as raw materials for petroleum sulphonates. The preferred feed is the dialkylbenzene which can give products of similar performance to a custom-made C20+ alkylbenzene. The alkylate still bottoms (as these materials are often called) also contain diphenyl alkanes. When sulphonated, these become highly water soluble and should be removed, either by distillation of the organic feed, or separation from the oil soluble sulphonates. 

The reaction of diolefins in the alkylation unit results in the formation of undesirable products diphenyl alkanes, polymers, and indane/tetralins (Fig. 3). The first two result in yield loss, while the third lowers product quality. Selective hydrogenation can be used to convert diolefins to mono-olefins. The UOP DeFine process was commercialized for this purpose in 1986. Use of the DeFine process in LAB production results in approximately 50% reduction in the formation of heavy alkylate and approximately 5% increase in LAB yield. The reaction takes place over... 

The residue yield decreased to 0.65 by 30 min, which represents higher conversion than attained in neat pyrolysis because of the catalytic cleavage of thermally stable diphenyl alkanes and ethers. 

Figure 13.17 shows that incorporating a flexible segment close to the center of mass of a rigid molecule allows us to obtain a much larger decrease in diffusion coefficients (D) than the effects of size described in Figure 13.16. In the case of diphenyl alkanes, D decreases by 10 when 1-3 carbons are incorporated between two aromatic rings. This is associated with an anchor effect of aromatic rings, which are temporarily trapped by the absence of free volumes facilitating the reorientation or tilting of the aromatic ring [FAN 13].

Figure 13.17. Scaling law associated with the diffusion of diphenyl alkanes. Effects of a) length of the flexible segment (Nc = 0, 1, 2) and b) the T-Tg difference [FAN 13f (Fora color version of this flgure, see www.iste.co.uk/hamaide/pofymers.zip)...

The emission spectra of certain aromatic molecules exhibit a characteristic change in concentrated systems which is due to the emission of a sandwich complex of an excited molecule with a second molecule in the ground state. Such complexes are called excimers. 2 In 1965, it was reported that dilute solutions of a,co-diphenyl-alkanes, ( )-(CH2) have an emission spectrum... 

The cyclization of diphenyl ether 206 to the cyclic sulfone derivatives 208 and 209 achieved by prolonged heating with a large excess of the reagent is analogous to similar reactions observed with biphenyl and the diphenyl alkanes (see Section 2, pp 42 and 40). 4-Bromodiphenyl ether by treatment with excess chlorosulfonic acid (two equivalents) at 25-30 °C afforded the 4-sulfonyl chloride (45%). In this molecule, the other reactive 4-position is blocked by the bromine atom. In contrast, with diphenyl ether 206 all attempts to obtain the monosulfonyl chloride by reaction with chlorosulfonic acid failed, and the only isolated product was the 4,4 -disulfonyl chloride. In the case of 4,4 -dibromodiphenyl ether, in which... 

On the other hand, 1,1,1-trisubstituted alkanes behave similarly to aldehydes, yielding pyrjdium salts (128) with identical substituents in positions 2 and 6. Thus, Dorofeenko and co-workers condensed 2 moles of acetophenone with 1 mole of benzotrichloride in the presence of perchloric acid obtaining 2,4,6-triphenjdpjTylium perchlorate with 1 mole of ethyl orthoformate, they obtained 2,6-diphenyl-pyrylium perchlorate (57) from o-hydroxyacetophenone, ortho-formic ester and perchloric acid, 4-ethoxybenzopyrylium perchlorate was formed. 

Examples of such reactions are well known. Sloan, Breslow, and Renfrow found that both alkane and arenesulphonyl azides insert into the carbon-hydrogen bonds of saturated hydrocarbons 12>. Thus, 1-pentane,- 2-propane- and -toluene-sulphonyl nitrene inserted into cyclohexane to give 54, 60, and 58% yields of the corresponding IV-cyclohexylamide derivatives 8>. Similarly, 2-phenoxybenzene-, diphenyl sulphide-2-, and... 

Recently, the thermal decomposition of diaryl alkanes such as dibenzyl and 1,3-diphenyl propane has been studied by Sato and coworkers (13), Collins and coworkers (14). These compounds were confirmed to be decomposed to alkyl benzenes gradually as a function of carbon chain length. 

For example, with the Co-I-PPh catalyst, methyl acetate reacts with synthesis gas to form ethyl acetate. All of the primary and secondary alcohols tested (C thru C ) decompose during long-term operation. The major decomposition products include aldehydes, alkyl iodides, and ethers. Ketones are readily hydrogenated and the resulting alcohols decompose. Good solvents in terms of stability are diphenyl ether and alkanes. The acetaldehyde rate is somewhat low (1.8 M/hr) in diphenyl ether, and the selectivity is low in alkanes. In addition, these solvents do not have good solubility properties, especially in product refining. 

Bei der Umsetzung von Benzyl-quecksilberchlorid mit Salpetersaure zu 3,4-Diphenyl-furazan-2-oxid werden moglicherweise Nitro-alkane als Zwischenstufe durchlaufen341 ... 

Sekundare Nitro-alkane liefern die tiefgefarbten 2,2-disubstituierten 2H-Benzimidazo 1-1,3-bis-oxide322 324 eine Verbindung dieses Typs wird auch mit Diazo-diphenyl-methan326 er-halten. Mit Formaldehyd/Alkali320 bzw. Formaldehyd/prim. Amin327 entstehen 1,3-Dihydroxy-2,3-dihydro-benzimidazole ... 

Alkyl-bromide (bzw. Allyl-bromid) sowie Ketone reagieren mit dem aus Benzophenon-methylimin und Lithium-diisopropylamid gebildeten l,l-Diphenyl-2-aza-allyl-lithium un-ter Substitution zu l-(Diphenylmethylen-amino)-alkanen bzw. l-(Diphenylme-thylen-amino)-2-hydroxy-alkanen, deren saure Hydrolyse 1-Amino-alkane bzw. 1-Ami no-2-hydroxy-alkane ergibt1. 

The kinetics of the oxidative addition of nitriles to Ni(P—P)2 have been studied. The organocyano nickel(II) complexes presumably have a dinuclear structure with trans planar coordination for the nickel atom.270 Some of the [Ni(CN)(R)(PR3)2] compounds (R = alkyl, aryl) are unstable and therefore cannot be isolated in the solid state. Their decomposition in solution promotes the formation of alkanes, alkenes, diphenyl, etc.217... 

Intramolecular excimer formation of diphenyl and triphenyl alkanes was investigated in detail. For example, see Ref. 310. 

An interesting photochemical approach to 4,5-disubstituted N-alkylimidazoles consists of the photolysis of 2,3-dihydro-5,6-disubstituted-pyrazines that can be easily prepared from 1,2-diketones and 1,2-diamino-alkanes. For example, the preparative-scale photolysis, in absolute EtOH with high-pressure Hg lamp (Pyrex filter), of 5,6-dimethyl- or 5,6-diphenyl-2,3-dihydropyrazines 54, yields the corresponding N-methyl-imidazoles 57 in high yields (Scheme 12.16). The reaction mechanism involves the formation of an enediimine intermediate 55, followed by cyclization and re-aromatization [41]. 

Alkan- und Arenthiophosphonsaure-dichloride lassen sich in guten Ausbeuten mit Aromaten unter Friedel-Crafts-Bedingungen arylieren521. So erhalt man beispielsweise Diphenyl-methyl-phosphansulf id (Sdp. 157—159°/0,1 Torr [0,013 kPa]) in 81% Ausbeute aus Methanthiophosphonsaure-dichlorid, Benzol und Aluminiumtrichlorid521 ... 

Aus Thiophosphorsaure-dichlorid-fluorid mit Thiophenol103 (schlechter mit Alkan-thiolen104) in Toluol in Gegenwart von Pyridin (Trithiophosphorsdure-S,S-diphenyle-ster-fluorid 31% Sdp. 168-17270,2 Torr/27 Pa)103. 

Ono and Ware"" have measured the absorption, emission, and excitation spectra, the fluorescence decay times, and the quantum yields of a series of substituted diphenylmethylenes in rigid matrices at low temperatures. Acean-thrylene shows S2- So emission in hexane with a yield of 0.017 and lifetime of 4.3 ns. The low-temperature fluorescence spectra of bis-2-naphthyl-alkanes and their derivatives have been studied. Excimer formation is an activated process. The fluorescence and absorption spectra of 1,1-diphenyl-ethylenes have been analysed in some detail by Gustav and Bolke. " The S — Si transitions in trans isomers of phenylnaphthylethylenes have been assigned by picosecond absorption spectroscopy. Effects of solvent viscosity and the role of conformers in the mechanism of isomerization are elucidated. The production of non-equilibrium conformer concentrations in glassy solutions of diarylethylenes at 77 K due to restrictions imposed by the solid matrix has also been reported. Free jet excitation and emission spectra of diphenyl-butadiene show clearly the lowest excited Ag state and give a lifetime of 52.8 ns for 0-0 excitation.Electric field-induced charges in the optical... 

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