Observations from metal chelation studies.
| Compound | Cu2+ | Zn2+ | Al3+ | Fe3+ | |||||
|---|---|---|---|---|---|---|---|---|---|
| % ΔAa | Shiftb | % ΔAa | Shiftb | % ΔAa | Shiftb | % ΔAa | Shiftb | ||
| 5c | |||||||||
| λ max | 256.39 | 0 | 0 | 0 | 0 | — | — | — | — |
| 287.7 | 0 | 0 | 0 | 0 | (+)58.41 | (−)4.76 | (−)171.14 | (−)6.22 | |
| 326.31 | 0 | 0 | 0 | 0 | (+)141.5 | (+)0.42 | — | — | |
| 5d | |||||||||
| λ max | 254.28 | (+)8.76 | (−)1.21 | (+)6.04 | (−)1.21 | (+)9.36 | (−)1.21 | (+)48.04 | 0 |
| 288 | (−)34.63 | 0 | (−)34.62 | (−)1 | (−)31.94 | (−)2 | (−)1.19 | (−)4 | |
| 324.35 | (+)3.75 | (+)0.79 | (−)8.41 | 0 | (−)7.13 | (−)0.41 | (−)21.00 | 0 | |
| 5h | |||||||||
| λ max | 257.15 | (−)10.20 | (+)1.03 | (+)17.14 | (+)0.31 | (+)11.02 | 0 | (−)65.31 | (+)0.67 |
| 288.5 | (−)9.15 | (−)0.5 | (+)20.42 | (−)0.36 | (+)3.52 | (+)1.4 | (−)105.63 | (+)0.67 | |
| 325.74 | (+)5.65 | (+)0.74 | (+)11.01 | (−)0.26 | (+)10.42 | (−)0.26 | (−)27.08 | (+)0.36 | |
| 5i | |||||||||
| λ max | 257.85 | 0 | 0 | 0 | 0 | — | — | — | — |
| 288.78 | 0 | 0 | 0 | 0 | (−)104.57 | (−)3.68 | (−)221.83 | (−)2.6 | |
| 325.93 | 0 | 0 | 0 | 0 | (+)43.01 | (−)1.09 | (+)48.38 | (−)3.25 | |
| 5n | |||||||||
| λ max | 254.72 | (+)17.34 | (−)1.09 | (+)1.24 | (−)1.08 | (+)5.88 | (−)1.08 | (−)54.80 | (−)0.72 |
| 290.57 | (+)18.93 | (+)0.67 | (+)2.43 | (+)2.07 | (+)5.82 | (+)2.07 | (−)70.39 | (+)2.07 | |
| 324.71 | (+)16.59 | 0 | (+)4.255 | (−)0.67 | (+)4.25 | (−)0.67 | (−)23.62 | (+)0.36 | |
| 5q | |||||||||
| λ max | 258.23 | 0 | 0 | 0 | 0 | — | — | — | — |
| 288.46 | 0 | 0 | 0 | 0 | (−)78.07 | (−)3.62 | (−)185.50 | (−)2.92 | |
| 325.56 | 0 | 0 | 0 | 0 | (+)39.70 | 0 | (+)47.94 | 0 | |
a
Data represented here is percentage change in absorbance; (+) indicating a decrease in absorbance and (−) as increase; calculated by the formula [(abs of tested compound − abs of complex)/abs of tested compound] × 100.
b
Data represented here is shift in nm; (+) indicates a hypsochromic shift and (−) indicates a bathochromic shift as calculated from the formula [λmax of tested compound − λmax of complex].