Mechanism of thermolysis of .alpha.-chloro ethers in aprotic solvents

Extreme solvent effects on reaction rate constants at supercritical fluid conditions

“…At 423 K, the values are 0.337 mol/kJ, 65.1, and 0.95. The slope is nearly the same as the value of 0.342 that was obtained for a series of liquid solvents at 298 K (Kwart and Silver, 1975), although the intercept is different because of the activation energy. These results suggest that solvatochromic parameters are a useful tool for the prediction of pressure effects on rate constants in supercritical fluids.…”

“…For rate constants on the order of 5 x lo-' and 1 x the uncertainties were approximately 50 and 5%, respectively. The rate constants in several experiments that were performed in liquid chloroform and carbon tetrachloride agreed with those of Kwart and Silver (1975) to within 10%.…”

“…The activation energy, 27.6 kJ/mol, is much smaller for difluoroethane than for most of the liquid solvents studied by Kwart and Silver (1975), Table 2. The activation enthalpy, Ah* = h7 -h,, and activation entropy, As* = S* -S, , were calculated using transition state theory, Eqs.…”

“…* : : was studied previously in a series of liquid solvents and determined to be first order (Kwart and Silver, 1975). A possible mechanism similar to an El mechanism was suggested and is shown in Figure 2.…”

“…The reactant a-chlorobenzyl methyl ether was synthesized from benzaldehyde-dimethylacetal (Kwart and Silver, 1975). It was stored in dry ice under a nitrogen atmosphere.…”