Calculator Plugins : Red & blue representation of pKa values

This manual explains the difference between the representations of coloured pKa values:


Static red & blue representation of pKa values
 

The static (default) red & blue colour annotation is related to the ionization steps shown in the figure below.
 

Fig. 1 Static red & blue colouring schema

 

The static red & blue coloring schema does not depend on the ionic form of a molecule submitted to the pKa calculation. The next three species have the same pKa values and the same colour.
 

Fig. 2 Calculated pKa of the deprotonated, neutral and the protonated forms of ammonia in the static red & blue colouring schema

 

Dynamic red & blue representation of pKa values

 

The dynamic (non-default setting) red & blue colouring schema depends on the submitted molecule.
 

Fig. 3 Dynamic red & blue colouring schema
 

The result of the previous ammonia example with the non-default pKa calculation:
 

Fig. 4 Calculated pKa of deprotonated, neutral, and the protonated forms of ammonia according to the dynamic red & blue colouring schema

 

Differences between the static and the dynamic red & blue colouring schema are summarized in the following table.
 

  static dynamic
Subject of calculation neutral state of the submitted molecule the submitted molecule
Blue colorassigned to the acid dissociation constant between the neutral base and its conjugated acid the acid dissociation constant between the submitted base and its conjugated acid
Red colorassigned to the acid dissociation constant between the neutral acid and its conjugated base the acid dissociation constant between the submitted acid and its conjugated base
setting in the Options panel

Tab. 1 Differences between the static and dynamic red & blue colouring schema