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Physical & Chemical properties

Partition coefficient

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Description of key information

Partition Coefficient for Sn(II) part of salt:  Waived, as this property is not required nor relevant for an insoluble inorganic species.
Partition Coefficient for 2-ethylhexanoic acid is log Kow = 2.64

Key value for chemical safety assessment

Log Kow (Log Pow):
2.64
at the temperature of:
25 °C

Additional information

When introduced to water, the Tin bis(2-ethylhexanoate) substance will dissociate (99% dissociated at pH > 6.8), where the Sn(II) will be initially speciated as the Sn(OH)2 substance, which will be oxidized in oxygenated solutions to become the insoluble solid SnO2. The 2-ethyl hexanoic acid part of the salt has its maximum water solubility at pH > 6.8, where it exists completely as the ethyl hexanoate anion. By definition, log Kow must be determined at pH where an ionizable substance is fully neutralized, in this case, pH < 2.8. The reported log Kow of 2-ethylhexanoic acid is 2.64. Because this value is the preferred/accepted value among those critically reviewed by Sangster (1989) and Hansch et al. (1995), the determination is assumed to be made at 25 °C and pH where the substance is not ionized. The distribution coefficient log D for this substance at pH 7 is estimated to be 0.55 (ACD Labs Log D Suite, v5.16). Therefore, at pH encountered in the environment, the substance will have very low potential for adsorption to organic matter of soils/sediments, or to bioaccumulate in aquatic organisms.