Table 3.
Peak wavelength number (cm−1) and reference data for reference dyes and samples M1, A3.2, and A3.1.
| M1 (50 months) | A3.2 (39 months) | A3.1 (date) | Reference data [6] | Type of vibrations |
|---|---|---|---|---|
| 525 | 525 | 525 | 524 (CV) | δ (CNC) |
| + | + | + | 558 (CV) | γ (CCC)/δ (CNC)/δ (CC center C) |
| 726 | 724 | 726 | 724 (CV) | ν (CN) |
| 912 | 916 | 912 | 915 (CV) | ν (CC) ring |
| 997 | 993 | 997 | 995 (MY) | |
| 1137 | 1141 | 1141 | 1147 (MY) | |
| 1184 | 1180 | 1180 | 1178 (CV) | ν s (CC center C)/δ (CCC) breathing /δ r (CH 3 ) |
| 1188 | 1188 | 1188 | 1188 (MY) | |
| 1300 | 1295 | 1306 | 1300 (CV) | ν as (CC center C)/δ (CCC) ring /δ (CH) |
| 1361 | 1365 | 1365 | 1369 (CV) | ν (CC center C) |
| 1430 | 1436 | 1428 | 1447 (CV) | δ as (CH 3 ) |
| 1539 | 1540 | 1534 | 1536 (CV) | ν (C ring N)/δ s (CH 3 ) |
| 1586 | 1582 | 1586 | 1591 (CV) | ν (C-C) ring |
| + | 1622 | 1622 | 1622 (CV) | ν (C-C) ring |
v, stretching vibrations; δ, planar deformation vibrations; s, symmetric; “+,” small peak observed; as, asymmetric. Values in bold indicate the matching peaks of crystal violet (CV). Values in italics indicate the matching peaks of metanil yellow (MY).