Figure 1
Figure 2
Figure 3
The prepared metal carboxylates_
| Comp. Nr. | Starting metal salt | Yield | Colour | Molar conductivity | Assumed composition | Elemental analysis theor. | Elemental analysis exp. | ||
|---|---|---|---|---|---|---|---|---|---|
| % | μS·mol−1·cm2 | % C | % H | % C | %H | ||||
| 1 | CoCl2·6H2O | 96 | pink | 9 | Co(L-2H)(2H2O) | 51.84 | 8.31 | 51.70 | 8.55 |
| 2 | CuCl2·2H2O | 75 | light blue | 3 | Cu(L-2H)(2H2O) | 51.44 | 8.25 | 51.17 | 8.03 |
| 3 | NiCl2·6H2O | 82 | light-green | 10 | Ni(L-2H)(3H2O) | 50.17 | 8.43 | 50.19 | 8.46 |
| 4 | La(NO3)3·6H2O | 87 | white | 2 | La(L-3H)(2H2O) | 44.90 | 7.02 | 44.91 | 7.19 |
| 5 | VOSO4·5H2O | 84 | grey-blue | 11 | VO(L-2H)(3H2O) | 49.34 | 8.28 | 49.30 | 8.03 |
| 6 | FeCl3·6H2O | 86 | light-brown | 3 | Fe(L-3H)(3H2O) | 50.46 | 8.28 | 50.50 | 7.95 |
| 7 | MnCl2·2H2O | 95 | brownish-white | 5 | Mn(L-2H)(2H2O) | 52.27 | 8.37 | 52.79 | 8.30 |
Characteristic signals in IR and HR-MS spectra_
| Substance | νas(COO−) a | νs(COO−) b | Δν(COO−) c | ν(C=O) | m/z theor. d | m/z found |
|---|---|---|---|---|---|---|
| 1 (Co) | 1590 | 1394 | 196 | 1704 | 472.1872 | 472.1875 |
| 2 (Cu) | 1567 | 1417 | 150 | 1704 | 476.1836 | 476.1839 |
| 3 (Ni) | 1575 | 1417 | 158 | 1704 | 471.1893 | 471.1899 |
| 4 (La) | 1558 | 1403 | 155 | --- | (552.1603) | --- |
| 5 (V) | 1563 | 1423 | 140 | 1705 | 480.1928 | 480.1932 |
| 6 (Fe) | 1539 | 1440 | 99 | --- | 468.1811 | 468.1816 |
| 7 (Mn) | 1569 | 1409 | 160 | 1703 | (468.1920) | --- |
| 8 (L) | --- | --- | --- | 1691 | 415.2696 | 415.2701 |
Antimicrobial activity of metal carboxylates and the ligand (MIC = minimum inhibitory concentration)_
| Substance Nr. | Metal | MIC (mg/ml) | ||
|---|---|---|---|---|
| S. aureus | E. coli | C. albicans | ||
| 1 | Co | 0.22 | 0.44 | 0.88 |
| 2 | Cu | 0.44 | 1.75 | 0.44 |
| 3 | Ni | >3.5 | 1.75 | 0.88 |
| 4 | La | 1.75 | 1.75 | 1.75 |
| 5 | V | 0.05 | 3.5 | 0.88 |
| 6 | Fe | 3.5 | 0.88 | 0.44 |
| 7 | Mn | 3.5 | 3.5 | 0.44 |
| 8 | (ligand) | 1.75 | 3.5 | 0.88 |