Page 398 - Advanced Organic Chemistry Part A - Structure and Mechanisms, 5th ed (2007) - Carey _ Sundberg

379
X 6A:6B
PROBLEMS
CN 100:0
77:23
CO 2 CH 3
Ph 51:49
p-NO 2 Ph 75:25
p-FPh 52:48
p-CH 3 OPh 39:61

3.7
a. Create Hammett plots versus and for the reaction shown below from
−
the data given. Determine the value of and compare the correlation with the
two sets of substituent constants.

Y Y CH SO 3 –
2
–
+ OH
SO 2
O
OH
s
Y kM −1 −1
H 37.4
CH 3 O 21.3
24.0
CH 3
Br 95.1
1430
NO 2
b. The pseudo-first order rate constants for acid-catalyzed hydration of substi-

tuted styrenes in 3 5M HClO at 25 C are given. Plot the data against and
4
+
and determine and . Interpret the significance of the results.
+
3.5 M HClO 4
Y CH CH 2 Y CHCH 3
OH

8 −1
Y k×10 s
4-CH 3 O 488 000
16 400
4-CH 3
H 811
4-Cl 318
1 44
4-NO 2
c. The acidity of a series of substituted benzyldimethylammonium ions has
been measured. Determine whether these data are correlated by the Hammett
+
equation using and . What is the value of ? What interpretation do you
put on its sign and magnitude?

Y Y
+
CH N H(CH ) CH 2 N(CH ) + H +
2
3 2
3 2