| Compound | ν (OH) phenolic | ν (NH) | ν (C=N) | νas (SO2) | νs (SO2) | δ (SO2) | δ (OH) | ν (C-O) | Solvent (EtOH/ H2O) | ν M-O/ M-N | λmax, nm assignments | Structure |
| HNB, L1 C17H14N2O3S | 3450 | 3161 | 1620 | 1318 | 1167 | 574 | 1241 | 1077 | - | - | 366 (n-p*, SO2), 354 (n-p*, C=N), 320 (p → p*, SO2), 310 (p → p*, C=N), 254 (p → p*, naphthyl), 246 (p → p*,phenyl), |
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| [Cu(L1)2]n∙nH2O | - | 3217 | 1615 | 1332 | 1170 | 576 | - | 1089 | 3300 - 3600 | 515/460 | 713 (2B2 → 2E), 417 (CT) | pesudo-tetrahedral |
| [Ni(L1)2∙(EtOH)1/2]n∙2nH2O | - | 3204 | 1617 | 1329 | 1170 | 582 | - | 1089 | 3300 - 3600 | 520/438 | 620 (1A1/ → 1E//, 466(1A1/ → 1E// | trigonal bipyramidal |
| [Co(L1)2]n | - | 3205 | 1616 | 1328 | 1165 | 585 | - | 1090 | - | 535/385 | 480 (2A1g → 2B1g), 410, 430 (CT) | square-planar |
| HNT, L2 C18H16N2O3S | 3470 | 3196 | 1624 | 1328 | 1164 | 572 | 1275 | 1075 | - | - | 474 (n-p*, SO2), 442 (n-p*, C=N), 390 (p → p*, SO2), 366 (p → p*, C=N), 350 (p → p*, naphthyl), 336 (p → p*, phenyl) |
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| [Cu(L2)2]∙1/2EtOH | - | 3219 | 1600 | 1330 | 1168 | 574 | - | 1090 | 3300 - 3600 | 515/390 | 716 (2B2 ® 2E), 402 (CT) | pesudo-tetrahedral |
| [Ni(L2)2∙(EtOH)1/2] | - | 3207 | 1600 | 1325 | 1168 | 579 | - | 1090 | 3300 - 3600 | 510/400 | 610 (1A1/ → 1E//, 478(1A1/ → 1E// | trigonal-bipyramidal |
| [Co(L2)2]∙1/2EtOH∙1/2H2O | - | 3208 | 1597 | 1322 | 1167 | 581 | - | 1089 | 3300 - 3600 | 500/410 | 535 (2A1g → 2B1g) | square-planar |