Table 2. Identified Species in the Positive- and Negative-Ion Mode ESI-MS Spectra of Complexes 1–4a.
| ion | composition | experimental m/zb | calculated m/zb | error (ppm)c |
|---|---|---|---|---|
| [VV(L1)2]+ | C26H34N6O2S4V | 641.1066 | 641.1060 | 0.9 |
| [VIV(L1)2] + Na+ | C26H34N6NaO2S4V | 664.0960 | 664.0958 | 0.3 |
| [VIV(L1)2] + K+ | C26H34KN6O2S4V | 680.0699 | 680.0697 | 0.3 |
| [VVO2(L1)]− | C13H17N3O3S2V | 378.0161 | 378.0156 | 1.3 |
| [VV(L2)2]+ | C38H42N6O2S4V | 793.1688 | 793.1686 | 0.3 |
| [VIV(L2)2] + Na+ | C38H42N6NaO2S4V | 816.1585 | 816.1584 | 0.1 |
| [VIV(L2)2] + K+ | C38H42KN6O2S4V | 832.1323 | 832.1323 | 0.0 |
| [VVO2(L2)]− | C19H21N3O3S2V | 454.0480 | 454.0469 | 2.4 |
| [VV(L3)2]+ | C26H20N4O2S4V | 598.9911 | 598.9903 | 1.3 |
| [VIV(L3)2] + Na+ | C26H20N4NaO2S4V | 621.9814 | 621.9801 | 2.1 |
| [VIV(L3)2] + K+ | C26H20KN4O2S4V | 637.9561 | 637.9540 | 3.3 |
| [VVO2(L3)]− | C13H10N2O3S2V | 356.9586 | 356.9578 | 2.2 |
| [VV(L4)2]+ | C38H28N4O2S4V | 751.0533 | 751.0529 | 0.5 |
| [VIV(L4)2] + Na+ | C38H28N4NaO2S4V | 774.0427 | 774.0413 | 1.8 |
| [VVO2(L4)]− | C19H14N2O3S2V | 432.9899 | 432.9891 | 1.8 |
a
The data are referred to the mass spectra recorded in CH3CN.
b
Experimental and calculated m/z values refer to the monoisotopic peak with the highest intensity.
c
Error in ppm with respect to the experimental value, calculated as 106 × [Experimental (m/z) – calculated (m/z)]/calculated (m/z).