S9T 
Solutions (1697). 
a Compound 
pH °c I II III IV la IVa V Va 
2 tsa) , 25 176 rf 322 a 232 ; 249 . 62.4 , 40.6 5! Bo GYs Sue ely 
k (sec) 4.56x10-° 2.5xl0 ~ 3.46x10-" 3.22x10- 1.29x10° 1.96x10° 3.9xl0° 4.2x10 
tg. 44) 40 26.4 41.2 32.8 36.4 11.9 8.1 10.7(h) 
(sec~) 3.04x10-7 1.95x107? 2.45x107/  2.21x107’ 6.74x107’ 9.90x107’ 1.8x107> 
E, (kcal /Mol) 24.8 26.2 24.2 23.8 20.4 19.9 18.9 
4 ty (a) 25 160 240 212 249 73.8 113 14.2 8(h) 
k (sec7!) 5.01x10-8 3.33x10~° 3.77x10-8 3.22x1078 1.09x10°/ 7.70x10-8 5.56x10~’ 2.4x107> 
i 40 29.1 36 32.4 36.4 14.5 20.2 2.9 
(sec) 2.76x10-/  2.23x10-7 2.47x107’ 2.21x10-7 5.54x107’ 3.98x10-7 2.76x1076 
a (kcal /Mo1) ea 23.5 23.3 23.8 20.05 212 19.6 
6 ti (a) 25 122 168 165 205 32.5 105 124 10.1 
k (sec7!) 6.59x10-8 4.78x10-8 4.86x107-8 3,91x10-8 2.47x10°’ 7.65x10-8 6.47x1078 7.95x10~/ 
2 @ 40 22.8 30 28 29.9 6.9 15.25 13.5 
k (sect) 3.53x107/ 2,68x107-” 2.87x10-? 2.68x10~’ 1.16x10™ 5.26x10-’ 5.95x1077 
E, (kcal /Mol) 20.8 21.4 21.9 23.8 19.1 23.8 27.4 
8 ty. 2) ; 25 38.2 67.1 73.8 68.4 2.77 8.95 124 2.25 
k (sec) 2.1xl07? 1.2x107” 1.09x107/  1.175x10-7 2.9x107° 8.96x10-?_6.47x10~8 3.56x107° 
try ©) 40 6.46 9.46 10.75 10.4 13.5(h)  38.8(h) 13.8 
k (sec7!) 1.24x10- 8.46x10-7 7.46x107” 7.72x10-7 1.43x107> 4.96x10-© 5.81x107/ 
E, _ (keal/Mol) 22.0 24.2 23.8 23.2 19.7 21.2 27.1 
10 tyy) (h) 25 19.6 28.6 31.5 29.3 65.5(min) 2.47 19.6(d) 23.5 
k (sec!) 9.82x10-© 6.73x10~-© 6.11x10"© 6.56x10-© 1.76x10-* 7.8x107? 4.1x107’ 8.2x10~6 
tisp (h) 40 2.12 4.2 5.52 5.8 15(min)  39.2(min) 2.8 
k (sec"l) 9.08x10-5 4.58x10-> 3.49x1079 3.31x107> 7.7x107* 2.95x10~* 2.87x10~6 
E, (kcal /Mol) 27.4 23.8 21.6 20.0 18.25 16.4 24.0 

Dimethoate Homologs 
Hydrolysis in Aqueous Buffered 


