Table 2: Infrared spectrum data of p-chlorophenyl maleanilic acid ligand and its metal complexes (band maxima in cm−1).
| Compound | υ(C=O) COOH | υ(C=O) amide(I) (N−C=O) | υ(O−H) | υ(N−H) amide | υ(C=O) carbonyl | υ(M−O) | υ(C−Cl) |
| L | 1,702 | 1,630 | 3,282 | 3,205 | — | — | 1,092 |
| Cr(CO)4L | 1,709 s | 1,629 m | — | 3,273 w | 1,971 m | 502 | 1,089 |
| Mo(CO)4L | 1,706 s | 1,630 m | — | 3,480 w | 1,971 m | 508 | 1,089 |
| W(CO)4L | 1,705 s | 1,654 m | — | 3,423 w | 2,057 m | 506 | 1,090 |
| Band property: s = strong, m = medium, w = weak. | |||||||