124
M. M. Kabanda and K. P. Otukile
Table 1 Relative energies (E, kcal/mol) and relative free energies (G, kcal/mol) for the
geometries of the species involved in the reaction between thiourea and chloroacetic acid, results
with different methods
Results of the study of the reaction of the iminothiol form of thiourea with chloroacetic acid
Iminothiol form
M06-2x/6-31+G(d,p)
M11-L/6-31+G(d,p)
MP2/6-31+G(d,p)
E
G
E
G
E
G
R iso
0.000
0.000
0.000
0.000
0.000
0.000
RC-t
−18.706
−7.702
−14.881
−4.088
−17.668
−6.943
TS1-t
60.368
72.580
50.635
62.407
66.808
79.256
IM1
−17.081
−5.320
−14.516
−2.692
−16.806
−6.196
TS2
−24.271
−12.303
−6.907
3.735
−10.280
0.702
IM2
−8.993
1.938
−7.598
3.171
−10.138
0.714
TS3
25.321
39.073
30.474
44.171
30.097
44.027
PC
−19.345
−9.272
−19.728
−9.780
−22.897
−12.351
P iso
−5.032
−11.142
−7.818
−14.173
−9.111
−15.579
Iminothiol form
R iso
0.000
0.000
0.000
0.000
0.000
0.000
RC-t
−17.400
−6.474
−15.390
−4.862
−14.689
−4.263
TS1-t
60.776
72.945
58.211
69.921
53.959
65.796
IM1
−15.227
−3.374
−29.624
−18.230
−13.019
−1.217
TS2
−7.532
4.337
−7.983
2.511
−5.826
5.057
IM2
−8.906
1.810
−8.794
1.868
−7.291
3.520
TS3
28.706
42.341
23.695
37.146
32.387
45.958
PC
−18.237
−8.346
−22.105
−9.893
−18.808
−9.207
P iso
−6.029
−12.240
6.456
1.479
−8.6213
−14.993
Results of the study of the reaction of the thione form of thiourea with chloroacetic acid
Thione form
R iso
0.000
0.000
0.000
0.000
0.000
0.000
RC
−24.581
−15.353
−20.243
−10.121
−22.295
−11.731
TS1
21.626
32.678
18.493
29.356
26.422
37.919
IM1
−11.928
−0.548
−8.980
2.641
−13.434
−3.024
TS2
−19.118
−7.531
−1.371
9.068
−6.908
3.874
IM2
−3.840
6.709
−2.062
8.504
−6.766
3.886
TS3
30.474
43.845
36.010
49.504
33.469
47.199
PC
−14.192
−4.501
−14.192
−4.447
−19.526
−9.179
P iso
0.121
−6.371
−2.282
−8.840
−5.739
−12.407
(continued)