Table 3: Stability constants of the ternary species in the CoII-DPA-dibasic acids and proton-association constants and their binary stability constants.
System | l | p | q | ra | log βb | Δlog K | Sc |
[Co(H2O)4]2 | 1 | 0 | 0 | −1 | −8.44(0.06) | 9.6E−7 | |
1 | 0 | 0 | −2 | −17.99(0.02) | |||
DPA | 0 | 1 | 0 | 1 | 7.65(0.01) | 2.4E−7 | |
0 | 1 | 0 | 2 | 10.21(0.02) | |||
Co-DPA | 1 | 1 | 0 | 0 | 4.55(0.02) | 3.6E−7 | |
Oxalic acid | 0 | 0 | 1 | 1 | 3.93(0.00) | 1.3E−9 | |
0 | 0 | 1 | 2 | 5.66(0.01) | |||
Co-Oxalic | 1 | 0 | 1 | 1 | 3.45(0.05) | 3.7E−7 | |
Co-DPA-Oxalic | 1 | 1 | 1 | 0 | 8.97(0.02) | 0.97 | 3.7E−7 |
CBDC acid | 0 | 0 | 1 | 1 | 5.68(0.01) | 5.4E−8 | |
0 | 0 | 1 | 2 | 8.80(0.02) | |||
Co-CBDC acid | 1 | 0 | 1 | 0 | 2.55(0.03) | ||
Co-DPA-CBDC acid | 1 | 1 | 1 | 0 | 8.70(0.09) | 1.67 | 1.7E−7 |
Malonic acid | 0 | 0 | 1 | 1 | 5.21(0.00) | 2.0E−9 | |
0 | 0 | 1 | 2 | 7.61(0.01) | |||
Co-malonic | 1 | 0 | 1 | 0 | 2.59(0.01) | 3.3E−8 | |
Co-DPA-malonic | 1 | 1 | 1 | 0 | 8.61(0.05) | 1.47 | 1.7E−7 |
Succinic acid | 0 | 0 | 1 | 1 | 5.21(0.00) | 5.3E−10 | |
0 | 0 | 1 | 2 | 9.26(0.01) | |||
Co-Succinic | 1 | 0 | 1 | 1 | 1.80(0.01) | 1.4E−7 | |
Co-DPA-succinic | 1 | 1 | 1 | 0 | 7.66(0.03) | 1.31 | 3.5E−9 |
Adipic acid | 0 | 0 | 1 | 1 | 5.11(0.01) | 3.3E−9 | |
0 | 0 | 1 | 2 | 9.35(0.02) | |||
Co-adipic | 1 | 0 | 1 | 1 | 1.61(0.02) | 2.4E−8 | |
Co-DPA-adipic | 1 | 1 | 1 | 0 | 7.48(0.04) | 1.32 | 2.5E−9 |
al, p, q and r are the stoichiometric coefficients corresponding to CoII, DPA, dicarboxylic acids and H+, respectively; | |||||||
bStandard deviation is given in parentheses; | |||||||
cSum of square of residuals. |