I Lab Services 

via the following well known functions: 

1

MV

f

d

(2)

d

MW

n

2

2

MV

f

n

(3)

n

2

1

MR

r

1

MV

f

(4)

14

P

r

The noteworthy discovery, made by senior scientists at ACD/Labs, is that there is a function of 

boiling point with respect to other additive molecular properties, which is a linear (additive) 

function too.  (Moreover, such an approach can also be used for prediction of the dielectric 

constant for organic compounds an added feature of ChemSketch).   

We express this function as: 

K

f

MV , BP

(5)

For different homologous sets, to a good approximation, the linear relationship is obeyed:  

K

f

MV , BP

c

c

n

 (6) 

0

1

C

where the c

i

 are empirically determined.   

From this, we can obtain two linearly predicted properties (using additive algorithms): our function 

K, and the molar volume (MV), which are similar in construction to our algorithm for prediction of 

logP.  Of course there are some differences: for example, the boiling point algorithm is different 

and more specialized for homologous sets and for other classes of compounds.  Once K and MV 

are obtained, the boiling point is easily calculated. 

4.17 LogP 

LogP contains a searchable database containing over 18,412 chemical structures with references 

to experimental logP values. 

In most cases, ACD/LogP DB calculates logP values with an accuracy 

0.3 or better.  Such an 

accuracy has been demonstrated for many different classes of compounds  (including acridines, 

amino acids and peptides, amphenicoles, barbituric acids, benzimidazoles, benzotriazoles, 

carbamates, furans, furazans, furoxans, imidazoles, indoles, 

 lactams, nucleosides and 

nucleotides, phenothiazines, phosphoroorganics, polyhalogenated aromatic and aliphatic 

compounds, purines, pyrazines, pyrazoles, pyridazines, pyridines, pyrimidines, quinolines, 

quinoxalines, saccharides, steroids, thiophenes, and many others). 

The resultant dialog box displays the following data: 

If there are any literature references containing information on the obtained value, the 

references are placed at the top of the list. 

Next is the calculated logP value. 

All of this data can be printed at once by clicking Print or you may wish to edit the default report 

page in ChemSketch and then print it (click Insert to start editing). 

ACD/I Lab via ChemSketch  

User's Guide 

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