Table 2: Infrared spectral bands (cm−1) of the ligand and its metal complexes.
| Compound phenolic (cm−1) | ν(OH...N) | ν(NH) | ν(C=O) | ν(C=N) | ν(C−O) phenolic |
ν(C−O) enolic |
ν(N−N) | ν(M−O) | ν(M−N) |
| H2L | 3,346 | 3,182 | 1,691 | 1,630 | 1,301 | — | 977 | — | — |
| [Ti(L)(Cl)(H2O)2] | — | 3,185 | 1,676 | 1,612 | 1,320 | 1,244 | 982 | 554 | 421 |
| [Cr(L)(Cl)(H2O)2] | — | 3,186 | 1,649 | 1,618 | 1,330 | 1,270 | 995 | 506 | 426 |
| [Fe(L)(Cl)(H2O)2] | — | 3,187 | 1,683 | 1,614 | 1,306 | 1,265 | 996 | 510 | 429 |
| [WO2(L)(H2O)] | — | 3,184 | 1,672 | 1,615 | 1,318 | 1,248 | 982 | 512 | 418 |
| [Th(L)(NO3)2(H2O)] | — | 3,185 | 1,675 | 1,610 | 1,314 | 1,246 | 994 | 522 | 412 |
| [UO2(L)(CH3OH)] | — | 3,183 | 1,678 | 1,604 | 1,324 | 1,258 | 998 | 548 | 428 |