The effect of pressure on the equilibrium in the Diels-Alder reaction between 9-chloroanthracene and tetracyanoethylene

Equilibrium constants for the Diels-Alder reaction of 9-chloroanthracene with tetracyanoethylene have been determined in the pressure range 0-970 kg cm-2 in 1,2-dichloroethane at 298 K and the value of the reaction volume (-20.6±1.5 cm3 mol-1) has been compared with the difference in partial molar volume of the dienophile (107.8±0.2), diene (170.7±0.5) and adduct (255.5±1.5 cm3 mol-1)

Solvent effect on the partial molar volume and the enthalpy of solution of gallium chloride

Partial molar volumes and heats of solution were determined for gallium chloride in benzene, toluene, o-xylene, mesitylene, 1,2-dichloroethane, ethyl acetate, acetonitrile, and 1,4-dioxane. A proportionality in changes in these characteristics is observed for weak π,ν-type complexes in alkylbenzene medium. The partial molar volumes of strong n,ν-type complexes approach a limiting value

Effect of a competing n donor on the rate of AlCl3-catalyzed Diels-Alder reaction of 9,10-dimethylanthracene with maleic anhydride

The catalytic effect of AlCl3 on the Diels-Alder reaction of 9,10-dimethylanthracene with maleic anhydride is dramatically weakened on addition of a competing n donor, dibutyl ether. The n,v complex of aluminum chloride with dibutyl ether is considerably more stable than the complex with maleic anhydride; therefore, the catalytic effect is suppressed even at comparable concentrations of these n donors

Determination of isothermic compressibility of solvent from changes in the absorbance of a dye solution under pressure

A new method of determination of the isothermic compressibility coefficient of a solvent from a change in the absorbance of a solution of the dye under elevated pressure (up to 100 MPa) was proposed. The method was checked by comparison with the known data for carbon tetrachloride and toluene at 25 °C. © Springer Science+Business Media, Inc. 2006

Enthalpies of solution of lithium perchlorate and Reichardt' dye in some organic solvents

Enthalpies of a solution, at 298 K, of lithium perchlorate and Reichardt' dye were determined in diethyl ether (-26.0; 23), acetonitrile (-38.3; 10), acetone (-66.3; 0), dimethyl sulfoxide (-75.3; -16), tetrahydrofurane (-49.0; 7.5), nitromethane (-62.0; 0), ethyl acetate (-37.2; 13) and methanol (-51.9; -33 kJ mol-1), respectively. For lithium perchlorate, a sharp dependence on integral enthalpy of solution was observed in diethyl ether and nitromethane in the range of low concentration. © 1997 Elsevier Science B.V

Apparent molar volumes and enthalpies of solution of tetracyanoethylene in some solvents and of butan-1-ol in n-octane at different concentrations

The effects of specific solute-solvent and solute-solute interactions on the change in the apparent molar volumes and in the enthalpies of solution, were found to be proportional in the title solutions at 25 °C

Activation and reaction volumes of the reactions of o-and p-nitrophenylsulfenyl chlorides with styrene and cyclohexene in some solvents

The effect of hydrostatic pressure below 1000 kg cm-2 on the rate of reactions of o-and p-nitrophenylsulfenyl chlorides with styrene and cyclohexene was studied. The activation and reaction volumes (cm3 mol-1) for the reactions of o-nitrophenylsulfenyl chloride with styrene in acetonitrile (-23.1 and -23.6), 1,2-dichloroethane (-29.2 and -24.7), chlorobenzene (no, -20.2), and anisole (-25.1 and -21.2) and for the reaction of p-nitrophenylsulfenyl chloride with styrene in carbon tetrachloride (-39.5±1.5 and -22.0) were determined. In carbon tetrachloride the activation volumes for the reactions of cyclohexene with o-and p-nitrophenylsulfenyl chlorides (-37.7±2.0 and -40.9±1.2 cm 3 mol-1, respectively) are almost the same and coincide with the data for the reactions with styrene. The considerable decrease in the volume of the transition state in the nonpolar solvent is considered as a consequence of the enhanced electrostriction of carbon tetrachloride in the solvate sphere of the transition state of the reaction, which excludes the nonpolar transition state of the sulfuran type. © 2007 Springer Science+Business Media, Inc