The photochemical decomposition of dicumyl peroxide and cumene hydroperoxide in solution

The photochemical decomposition of dicumyl peroxide and cumene hydroperoxide in the absence of oxygen has been investigated in two solvents. Reaction mechanisms have been suggested from a consideration of the products and the quantum yields. Dicumyl peroxide forms αα'-dimethyl benzyl alcohol exclusively at 3130 Å in n-hexane. At 2537 Å a little acetophenone is also formed. In carbon tetrachloride solution the product at 3130 Å is acetophenone and at 2537 Å a mixture of acetone and acetophenone is formed. In n-hexane the main product from cumene hydroperoxide is αα'-dimethyl benzyl alcohol. In carbon tetrachloride on the other hand acetone and acetophenone and a dark polymer are formed. For cumene hydroperoxide in n-hexane at 3130 Å the quantum yield is 1⋅57 at 20°C, the chain reaction being sustained by radicals formed from the solvent. In carbon tetrachloride solution the quantum yield is 0⋅75.