'Strongness' entry for pKa function?

How does one know what to enter for the 'strongness' pKa function? What scale is this on? Is this in reference to something?

 

Thanks,

Graham

Hi Jozsi,

could you please help me interpretting the strongness value in pKa?

 

Thanks,

VIktor

Hi,

Ok, but where was this expression found? :   "...strongness pKa function..."

Jozsi

This is one of the JChem for excel built in functions, it asks for 2 inputs (Molecule, Strongness), and I am confused about what to input for this strongness value.

JchemExcel just exposes the standard calculations plugin, so the standard CXN functions.

Hi,

Ok;  I attached a screenshoot about the  "strongness index" expression. I could  explain its  purpose in this manner: 

The calculated pKa values of a molecule are shorted according to their strength and in this way an ordered list (vector) of pKa values will be avalable for  postprocessing.   The "Strongness index" refers to one of the index  in this orderd vector.

The first  element  of  this vector  is the strongest  acidic or basic pKa value.  Vector indexing start with "0". The last element of this vector is the weakest acidic or basic pKa value.

Jozsi

Hi

It looks like the vector actually starts at index 1? Using zero returns a #VALUE! error.

Is there a way to determine the length of this vector should there be mulitple pKa values?

Thanks

Stephen

Hi Stephen,

at the moment not. This is available at calculation time in code, but it would be hard to decide where to display it.

What you could do now is to simply display the various values for the strongness indexes into multiple columns and have #value displayed for invalid indexes.

It would be possible later to create an explicit function which would return the length of that vector.

Best regards,

Tamas.