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Partition coefficient

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Description of key information

- 1.6090

Key value for chemical safety assessment

Log Kow (Log Pow):
-1.609
at the temperature of:
20 °C

Additional information

Acid Red 249:1 is a multiconstituent substance composed by the acidic and the sodium salt forms of the same structure (72.7 % and 14.95 % of the substances respectively). Partition coefficient was determined by OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method. The test was performed on the sodium salt of the Acid Red 249:1 and the partition coefficient results to be - 1.6090. Moreover, EPI Suite v4.10 has been used in order to compare the two structures. The two results, derived from estimation of partition coefficient by means of KOWWIN v1.68 estimate, are very similar (1.87 for the sodium salt and 4.45 for the acidic form) due to the great similarity between the two molecules.

 

The smile notations used for the estimations are:

Sodium salt

Clc5cc(/N=N/c2c(O)c3c(CS(=O)(=O)c1ccc(C)cc1)cc(cc3cc2S(=O)(=O)O[Na])S(=O)(=O)O[Na])c(Oc4ccccc4)cc5

 

Acidic form

Clc5cc(/N=N/c2c(O)c3c(NS(=O)(=O)c1ccc(C)cc1)cc(cc3cc2S(=O)(=O)O)S(=O)(=O)O)c(Oc4ccccc4)cc5

 

Considering the high similarity between the two estimated values and the composition of the substance, Acid Red 249:1 is expected to have the same partition coefficient of the sodium salt form as described by the experimental data (- 1.6090).