Zinc bis[O-(2-ethylhexyl)] bis[O-(isobutyl)] bis(dithiophosphate)

Dissociation constant

Link to relevant study record(s)

Reference

Endpoint:

dissociation constant

Type of information:

experimental study

Adequacy of study:

key study

Study period:

february 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 112 (Dissociation Constants in Water)

Version / remarks:

OECD Guidelines for the Testing of Chemicals. Test No. 112: Dissociation Constants in Water (Titration Method-Spectroscopic Method-Conductometric Method)

Deviations:

no

GLP compliance:

no

Dissociating properties:

yes

No.:

#1

pKa:

ca. 7.97

Temp.:

22 °C

Remarks on result:

other: in ethanol:water

No.:

#2

pKa:

ca. 7.99

Temp.:

22 °C

Remarks on result:

other: in ethanol:water

Titration was performed in a total of 4 different solvents, THF, acetone, isopropanol and ethanol (each with water).

Only results with Ethanol:water are tabulated above, as these were the only ones with a very well-defined titration curve.

All other solvents resulted in less well-defined curves and less accurate pKa values within 8.02 -8.10, which are consistent with ethanol:water results tabulated above.

Conclusions:

The pKa of the tets item at 22°C was 8.0.

Executive summary:

The pKa of the tets item at 22°C was 8.0.

Description of key information

The test item has a pKa of 8.0 at 22°C.

Key value for chemical safety assessment

pKa at 20°C:

8