Structural, Electronic, and Vibrational Properties of Isoniazid and Its Derivative N-Cyclopentylidenepyridine-4-carbohydrazide: A Quantum Chemical Study
Table 3
Comparison of calculated vibrational spectra of N-cyclopentylidenepyridine-4-carbohydrazide (CPPC) with (B3LYP)/6-311 G (d, p) and B3LYP/LANL2DZ.
B3LYP
Vibrational assignments
LANL2DZ
IR (Int.)
6-311 G (d, p)
IR (Int.)
29
0.189
29
0.0368
Whole molecule twists from middle
44
0.0329
43
0.0041
Whole molecule twists from middle
55
1.0643
56
0.5335
Ring B bends from middle
65
2.6343
64
1.7946
Twisting in ring B
115
1.2256
113
0.2943
Twisting in ring B
155
9.5443
152
8.6203
Both rings twist from middle
189
11.479
187
10.7292
Bending in whole molecule
221
0.5418
226
0.7907
(C–C–C) ring B
239
1.4716
243
1.22
(C–C–N–N)
284
4.2682
285
4.0485
(N–N–C=O)
324
4.6942
325
0.6016
Twist CH2 ring B
376
0.124
374
0.0949
Out of plane bending in ring A as a whole
395
2.2666
382
7.9387
(C–C–C=O)
453
8.0728
443
26.6387
(N–H)
466
11.181
464
11.8231
Out of plane bending in whole molecule
542
4.2055
492
20.6542
Whole molecule bends from middle
554
52.148
546
8.846
Twist CH2 ring B
573
25.912
559
0.4785
Twist CH2 ring B
588
7.2812
593
9.2922
(C–C=N)
654
1.136
657
0.8099
Ring A deformation
660
43.182
663
50.3605
Ring A breathing
690
28.825
696
16.6761
(C–C–C) ring A
739
0.3987
736
0.1654
Twist in ring B
750
13.234
746
10.518
(C–C–C) ring A
811
0.675
806
0.01
(CH2) ring B
835
12.940
825
13.797
(C–C–C)rRing B
837
25.375
830
1.1714
(C–C–C) ring A
873
2.6331
866
2.3196
(C–C–C) ring B
885
25.947
867
0.4876
(N–C=O) joint to both rings
887
3.846
889
4.1429
(C–C–H) ring A
906
5.1907
907
22.5923
Twist CH2 ring B
947
5.0577
933
2.7875
(C–C–H) ring B
951
5.9695
951
0.2745
Ring A breathing
966
2.0181
973
4.7925
(C–C–C) ring A
986
18.651
974
0.9688
(C–C–C) ring A
990
12.259
985
0.3854
(C–C–C) ring A
1002
2.3552
995
0.0806
Twist CH2 ring B
1027
5.8621
1021
12.9074
(C–C–C) ring B
1048
14.225
1050
17.0033
(C–C–H) ring A
1072
17.410
1067
8.9467
(C–C–H) ring A
1104
73.216
1105
114.2174
(C–C–H) ring A
1127
0.6851
1118
0.8245
Twist CH2 ring B
1144
9.5501
1144
23.861
(C–C–H) ring B
1184
15.684
1174
13.5043
(C–C=N) ring A + (C–C–C) ring B
1196
6.0684
1188
9.5816
(C–C–H) ring B
1203
3.3536
1195
23.0436
(C–C–H) ring A
1222
62.461
1209
146.2051
Twist CH2 ring B
1237
163.03
1217
51.1901
(C–C–C) ring A + twist CH2 ring B
1249
10.424
1232
34.5492
Ring A deformation
1266
9.0924
1256
4.27
Twist CH2 ring B
1283
2.845
1279
0.3718
Rock CH2 ring B
1305
0.2089
1295
0.4946
Twist CH2 ring B
1306
0.0683
1297
1.5912
Twist CH2 ring B
1312
0.6944
1301
0.9643
(C–C–H) ring A
1381
13.894
1385
14.4629
(C–C–H) ring A
1436
34.372
1416
17.0927
S(CH2) ring B
1441
13.808
1420
7.2964
S(CH2) ring B
1447
11.264
1442
5.421
(C–C–H) ring A
1461
9.7004
1456
3.4055
S(CH2) ring B
1469
1.2504
1463
17.0394
S(CH2) ring B
1487
313.60
1489
318.044
(C–N–H)
1529
37.617
1538
23.3689
Ring A deformation
1563
7.4055
1573
17.1708
(C–C) ring A
1604
227.40
1654
22.9328
(C=O)
1623
2.596
1715
302.3136
(C=N) joint ring B
2902
18.706
2890
12.407
(C–H) ring B
2925
15.584
2900
12.3498
(C–H) ring B
2938
21.950
2917
25.4822
(C–H) ring B
2939
41.648
2923
12.8395
(C–H) ring B
2954
38.945
2934
41.6752
(C–H) ring B
3001
42.309
2975
40.8297
(C–H) ring B
3009
30.010
2981
39.1011
(C–H) ring B
3017
50.383
2990
14.2807
(C–H) ring B
3072
8.0634
3031
21.1113
(C–H) ring A
3086
26.263
3038
23.6222
(C–H) ring A
3095
16.702
3061
12.3221
(C–H) ring A
3118
4.5408
3088
3.1852
(C–H) ring A
3416
17.207
3412
13.2313
(N–H)
: stretching; : in plane bending; : out of plane bending; S: scissoring;
: wagging; : torsion.
