“…They are 1.9 for (CH,),C+COOH, 1.5 for (CH,),C+COOCH3 and 0.3 for (CH,),CH+ COOH (CH,). Comparison with k d / k c z 3 for (CH,),C+ C(CH,), [29] and 0.65 for (CH,),CH+ HC (CH,), [30] reveals a diminution by a factor of 2 which is reasonable on statistical grounds.…”