Search

The rates of reaction between t-butyl chloride and water + methanol mixtures (mole fraction of methanol 0.0 to 0.4) have been measured in the temperature range 0 to 20°C. The activation parameters E*A, ΔS*, ΔH* and ΔG* are temperature dependent, and the variation of E*A with mole fraction of methanol (xm) is complicated. At 5°C E*A has a maximum at xm= 0.065 and a minimum at xm= 0.3. The maxima and minima, which are less pronounced at higher temperatures, can be explained in terms of the structure of the mixed solvent. ΔG* varies almost linearly with xm.

The possible formation of t-butyl chloride as an intermediate in the hydrogen chloride catalysed decomposition of t-butyl isopropyl ether according to the reactions is examined. Rates for t-butyl chloride decomposition and for the overall catalysed reaction are measured at 311�C and both a fourth-order Runge-Kutta method and Hamming's modified predictor-corrector method of numerical integration are used in computing the pressure-time curves due to the assumed reaction model using experi- mental values for k , and various assumed values for k2. It is found that no values for k2 can be found which generate the experimental curves and it is concluded that t-butyl chloride is not an intermediate of the reaction. If the hydrogen chloride catalysed decomposition of t-butyl isopropyl ether is typical of the family of catalysed decompo- sitions then alkyl halides generally have no role as intermediates.

The difference between the heat of solution of t-butyl chloride and that of its [2H6]-derivative in absolute ethanol is 22 cal./mole.