Table 1.
Selected vibrational data (cm−1) and assignments for isoniazid (INH) and the Cu(II) compounds (1–3).
| Compound | Assignment | |||
|---|---|---|---|---|
| INH | 1 | 2 | 3 | |
| - | 3437 m | 3434 m | 3449 w | νOH |
| 3306 m, 3213 sh | 3222 s | 3241 s | 3236 w | νasNH2 |
| 3112 s | 3098 s | 3101 sh | 3108 w | νsiNH2 |
| 3035 m, 3014 m | 3048 s, 3019 m | 3057 sh | 3061 sh, 3017 w | νCH |
| - | - | - | 2212 s | νasNCO |
| - | - | 2130 s | - | νasNCS |
| 1667 s | 1653 m | 1606 w | 1615 m | νC=O |
| 1635 m | 1648 s | 1648 m | 1655 sh | Scissoring NH2 |
| 1603 m | 1590 s | 1603 s | 1589 sh | νring + δCH +δHOH |
| 1556 s | 1547 s | 1554 m | 1537 m | νring |
| 1492 w | 1494 w | 1498 w | 1499 w | δCH + νring + δNH |
| 1412 m | 1415 m | 1415 m | 1416 m | δCH + νring |
| - | - | - | 1317 w | νsNCO |
| 1335 s | 1332 m | - | - | Rocking NH2 |
| - | 1284 w | 1268 w | 1283 w | νring |
| 1221 m | 1225 m, 1202 s | 1233 w, 1208 w | 1239 w | δCH + νring |
| 1141 m | 1139 m | 1131 w, 1098 w | 1131 w, 1103 w | δCH + νring + νCN |
| 1060 s | 1065 w | 1058 m | 1058 w | νring + δCH + δring |
| 996 m | 996 w | 988 w | 987 sh | νring + δring |
| 943 s | - | 941 w, 919 w | 945 w, 924 w | νNN + twisting NH2 + νNH2 |
| 888 w, 845 m | 906 w, 881 w, 858 m | 876 w | 868 sh | γCH + γC-CO-NH-NH2 |
| 747 w | 761 w | 755 w | 775 w, 756 w | γCH + τring + γCO +ν NC-S |
| - | 712 m | 715 m | 719 w | τring + γCO + γCH |
| 675 s | - | 690 m | 692 w | δring + νC-CO-NH-NH2 |
| 659 s | - | 664 sh | 658 w | δring + δCH |
| - | - | - | 620 w | δNCO |
| 504 w | 538 w | 504 w | 501 sh | τHNNH + γNH + δNCC + δC-CO-NH-NH2 + δOCC |
| 436 w | 463 w | 466 w, 430 w | 420 w | γNH + τHNNH + γCH + τring + δNCS |
ν = stretching; δ = in-plane bending; γ = out-of-plane bending; as = asymmetric; si =symmetric; s = strong, m = medium, w = weak, sh = shoulder.