Toluene ether

In benzonitrile both types of processes occur in parallel with similar efficiencies. In hydrogen-donating solvents (toluene, ether, dioxane, ethanol), hydrogen abstraction processes prevail [toluene (114) -> (123)]. 

Organomagnesium halide reagents RMgX (RX = CjH,Br, i-PrBr, n-BuBr, PhBr) react in toluene-ether with (t7 -Cp)2MoH2 to form compounds II, in which each molecule contains four Mo—Mg bonds " . When II is dissolved in THF a red solution is formed, which after concentration yields orange crystals of III. Compound III is monomeric with a Mo—Mg bond of length 273.2 pm, consistent for Mo as a one-electron donor. 

Physical properties of the polysilanes depend greatly upon the nature of the organic groups bound to silicon. A few of the many polysilanes are listed in Table I. Typically the linear polysilanes are thermoplastics, soluble in organic solvents like toluene, ethers,... 

X-ray structural analysis. Suitable crystals of compound 14 were obtained from toluene/ether solutions. X-ray data were collected on a STOE-IPDS diffractometer using graphite monochromated Mo-Ka radiation. The structure was solved by direct methods (SHELXS-86)16 and refined by full-matrix-least-squares techniques against F2 (SHELXL-93).17 Crystal dimensions 0.3 0.2 0.1 mm, yellow-orange prisms, 3612 reflections measured, 3612 were independent of symmetry and 1624 were observed (I > 2ct(7)), R1 = 0.048, wR2 (all data) = 0.151, 295 parameters. 

The photoreduction of nitrobenzene using p5o ex filtered light from a medium pressure mercury arc was studied in petroleum, toluene, ether, 2-propanol, tert-butyl alcohol, diethylamine, triethylamine, aqueous solutions of 2-propanol and diethylamine and also in aqueous t-butylalcohol containing sodium boro-hydiide 3 >. Varying amounts of aniline, azo- and azoxybenzene were obtained. In the presence of a fourty-fold excess of benzophenone, a six-fold increase in the rate of aniline formation in ethereal solution was observed, and aniline formation was completely suppressed by addition of biacetyl or octafluomaphthalene Since unreacted nitrobenzene could be recovered in these experiments, it is demonstrated that the triplet state of nitrobenzene was quenched. 

Sulfosalicyclic acid Isoamyl alcohol, toluene, ether 67)... 

A slurry prepared from 100 g (0.67 mol) of p-tert-butylphenol, 35 g (ca. 1.1 mol) of paraformaldehyde (Note 1), and 2.0 mL (0.02 mol) of 10 N sodium hydroxide (Note 2) 1n 600 mL of xylene Is placed in a 2-L, round-bottomed, three-necked flask fitted with a Dean-Stark water collector and a mechanical stirrer. The air in the flask is replaced with nitrogen, and the stirred contents of the flask are heated to reflux by means of a heating mantle. After 30 min a homogeneous solution is obtained, and after 1 hr a white precipitate begins to form. The reaction mixture is refluxed for 4 hr, the heating mantle is removed, the mixture is allowed to cool to room temperature, and the precipitate is removed by filtration. The crude product Is washed, in succession, with 400-mL portions of toluene, ether, acetone, and water and is... 

Note. Both the rearrangement In t-Butanol) and the double bond isomerization of (114) In Benzene) are quenched in a diffusion-controlled process by suitable triplet acceptors (e.g., naphthalene or 2,5-dimethylhexa-2,4-diene). The rearrangement (114) - (118) + (120) is also observed on irradiation in pyridine, the double bond isomerization (114) -> (122) in trifluorotoluene. In benzonitrile both types of processes occur in parallel with similar efficiencies. In hydrogen-donating solvents (toluene, ether, dioxane, ethanol), hydrogen abstraction processes prevail [toluene (114) - (123)]. 

Di-p-tolyl tellurium hydroxybromide, (CH3.C6H4)2Te(OH)Br, crystallises in minute prisms, M.pt. 269° to 270° C., sparingly soluble in alcohols, more soluble in chloroform, insoluble in benzene, toluene, ether or carbon disulphide. 

TLC Analysis. Small sample requirements, minimal sample preparation, high sensitivity, and low cost make TLC an attractive method for organic archaeometry. Its suitability for the detection of resin acids in complex mixtures was tested by subjecting the Carthaginian samples to a two-dimensional technique. Ether solutions of the organic material were spotted onto the plate and first freed from nonpolar components by elution in one direction with heptane. The residual carboxylic acids were then developed, with reference standards in adjacent tracks, in the second direction with heptane-toluene-ether (1 1 1). Under these conditions, 7-ketodehydro-abietic acid remains at or very near the origin (maximum retardation factor [Rf] = 0.04), but abietic acid and dehydroabietic acid are readily identified. 

Whatever the explanation, there is no doubt that polymer of molecular weight 500—800 is formed extremely rapidly at the start of polymerization and can be isolated from the final product. With fluorenyllithium [168], (toluene—ether, —60°C) a first order disappearance of monomer is observed, which extrapolates at zero time, not to the original added monomer concentration but to a concentration corresponding to the immediate loss of three molecules of monomer per initiator molecule. With 1,1-diphenylhexyllithium [174] (toluene,—30°C) this extrapolation corresponds to the rapid addition to the initiator of about five monomer units. In this case termination at various times and isolation of precipitant-soluble material confirms that polymer of molecular weight 830 is formed rapidly and does not change appreciably in amount throughout the polymerization. With butyllithium [173] (toluene, —30°C) the course of reaction is more complex in the initial stages but eventually a steady concentration of active centres is probably formed as the reaction settles down to first order decay in monomer. A second addition of monomer at the end of the reaction then produces a first order disappearance of monomer immediately. The two first order rate coefficients are identical. Evidently products are produced with butyl-lithium which disturb the reaction, and until these are removed a steady concentration of active centres is not achieved. 

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