Table 4. Stability Constants (log KML)a and pMb Values of H2L1, H2L2, H2dedpa, DOTA, and NOTA with M2+ = Cu2+ and M3+ = Ga3+ Metal Ions.
| log KML (M = Cu2+) | pCu | log KML (M = Ga3+) | pGa | |
|---|---|---|---|---|
| H2L1c | 23.05(2) | 21.96 | 23.80(2) | 19.5 |
| H2L2c | 22.70(2) | 22.8 | 20.69(1) | 20.8 |
| H2dedpa | 19.16(5)d | 18.5d | 22.9(1)e | 22.2e |
| DOTA | 22.21(1)f | 16.2 | 21.33g | 18.5g |
| NOTA | 21.6d | 19.2 | 30.98g | 27.9g |
a
KML defined as [ML]/([M][L]) (charges are omitted for clarity).
b
pM defined as −log [Mfree] when [L] = 10 μM and [M] = 1 μM at pH = 7.4.
c
This work, at 25 °C and I = 0.16 M (NaCl). pKa values of other complex species with either H2L1 or H2L2 and Ga(III) and Cu(II) are presented in Table S3.
d
From ref (21).
e
Corrected value (see the Supporting Information).
f
From ref (28).
g
From ref (13).