Figure 2. Plot of the relation between p-phenols toxicity,
log(1/IC 50), and QTAIM charges of Cu atoms of
data sets A (black squares), B (red circles) and C (blue triangles).
Dashed lines correspond to linear parameters in Table 2.
Copper charges in the2[Ph… Cu]2+complexes (as compared with original2Cu2+ ion charges) are a measure of
the O → Cu electron density transfer (Table S1 in Supplementary
information) and reflect the phenol toxicity (Table 2, Figs. 2, S2 and
S3 in Supplementary information). The QTAIM charges exhibit better
statistical parameters for Eq. (2) than the NBO and MPA ones, especially
for the dataset A (Table 2). Nevertheless, in all cases their fit is
better than for the Cu-O distances above.