Hexamethyl-benzene

Methylarenes (see also pentamethyl- and hexamethyl- benzenes). Recrystd from EtOH and sublimed in vacuum [Schlesener et al. J Am Chem Soc 106 7472 1984],... 

Solvent Et. Acetate in n-Alkane Benzyl Acetate Dm Hexamethyl- benzene Dm lO cm s l... 

The chemical shifts are for the solid state spectra obtained by the CP-MAS technique and referred to hexamethyl benzene (132.3 ppm compared to TMS). 

Small amounts of impurities greatly influence the melting point of hexamethyl benzene, and several recrystallizations of a fraction of close boiling range are necessary in order to prepare a sharply melting product. 

Durene, pentamethyl benzene and hexamethyl benzene have usually been prepared from benzene or one of its methylated derivatives by the Friedel-Crafts synthesis.1 Durene has been made from bromine derivatives of methylated benzenes by the Fittig reaction.2 It has also been obtained in 20 per cent yield by passing methyl alcohol and acetone vapors over heated alu-... 

Hexamethyl benzene.—Fraction VIII is fractionated in 250-cc. batches in a Claisen flask at 20 mm. pressure, the following fractions being collected ... 

This fractionation may be carried out in an ordinary Claisen flask, but there is some difficulty in maintaining the desired pressure due to the solvent action of the hydrocarbons on the rubber stopper. This difficulty may be avoided by the use of a Claisen flask with very long necks and a wide side-tube. The material should be distilled fast enough to prevent it from solidifying in the column and side tube. Prolonged heating of hexamethyl benzene also causes a considerable amount of decomposition to tars. 

The method for the production of large amounts of hexamethyl benzene is the rapid methylation of pentamethyl benzene or the durene filtrates. A mixture of 378 g. of pentamethyl benzene and 200 g. of anhydrous aluminium chloride is heated... 

The melting point of pentamethyl benzene is only slightly affected by recrystallization, because most of the impurity is hexamethyl benzene, which can be removed only by fractionation. 

Hexamethyl benzene decomposes when heated very strongly for any length of time. Better results arc therefore obtained if the distillations are carried out under reduced pressure. 

Overberger, J.E., Steele, W.A., Aston, J.G. (1969) The vapor pressure of hexamethylbenzene. The standard entropy of hexamethyl-benzene vapor and the barrier to internal rotation. J. Chem. Thermodyn. 1, 535-542. 

Peroxytrifluoroacetic acid, in oxidation, of hexamethyl benzene, 48, 87 of polyalkylarenes, 48, 89, 90 Peroxyvanadic acid, 45, 27 Phenanthrene, 9-phenyl-, 46, 91... 

There is sufficient information on CT complexes of this kind in Foster s book [6] for the Kus to be estimated. By extrapolating from 1,3,5-trinitrobenzene and 1,4-dinitrobenzene to PhN02 for any one electron donor (mesitylene or hexamethyl benzene), and from CC14 to solvents of D > ca 10, we find that at least for the three hydrocarbon monomers it is very unlikely that Kus > 10 2 1-mol 1. Therefore, since [Sv] = ca 10 mol-1 1 ([molar vol]"1), we find for m = 1 mold"1, that [MSv] <0.1 mold"1, which means that for these monomers >90% of the monomer is not bound in a CT complex, and the first objection is therefore not relevant. For the monomers containing both 7t- and n-donor groups, i.e., the VE, the Kus may well be greater, and therefore the formation of CT complexes may be important for these. 

Katz, et at(1) measured the efficiency of two different solutes (benzyl acetate and hexamethyl benzene) on a silica column 25 cm long and 9mm I D. packed with Partisi 10 (actual mean particle diameter 8.5 1) employing six... 

Mobile Phase Benzyl Acetate Hexamethyl Benzene... 

Values for k were obtained using the retention time of hexamethyl benzene as to. Values for k e were obtained employing tne retention time of the completely excluded solute polystyrene (t(e)o) (Mol. Wt.83,000). t(e)o was also employed for the measurement of the linear mobile phase velocity. 

On the basis of the irrational fits of the data to the Huber and Horvath equations, these equations will not be considered to satisfactorily describe the relationship between (H) and (u). According to Katz et a/ the same irrational behavior of the Huber and Horvath equation was observed if the data for hexamethyl benzene was also fitted to them. 

PRuC.mHjj, Ruthenium(II), [2-(diphenyl-phosphino)phenyl-C P](r) -hexamethyl-benzene)hydrido-, 36 182 PSC2H7, Phosphine sulfide dimethyl- and manganese complex, 26 162... 

Property 1,3,5-Trimethyl- benzene 1,2,4- Trimethyl- benzene 1.2.3- Trimethyl- benzene 1,2,4,5-Te tram ethylbenzene 1,2,3,5-Tfetramethyl-benzene 1,2,3,4-Tetramethyl-benzene Pentamethyl- benzene Hexamethyl- benzene... 

---