565404.fig.005a
(a)
565404.fig.005b
(b)
565404.fig.005c
(c)
565404.fig.005d
(d)
Figure 5: (a) Cambridge Crystallographic Database (CSD) search queries for six-membered hydrogen bond conjugated rings between the two oxygens of the α-carboxylate with a molecule of water in the vicinity. Hydrogen bonds and long-range dipolar interactions are defined by the geometric constraints and  Å and and  Å. C (gray), N (blue), any group (cyan), H (light-yellow), and O (red). (b) Plot of the number of structures versus the distances (H1O1) and (H2O2). (c) Plot of the number of structures versus the distances (OWO1) and (OWO2). (d) Distribution of the torsion angle O1–C–O2OW  versus the number of structures.