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Physical & Chemical properties

Dissociation constant

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Administrative data

Endpoint:
dissociation constant
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2 November 1998 to 27 November 1998.
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study performed in accordance with OECD test guidelines in compliance with GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1999
Report date:
1999

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 112 (Dissociation Constants in Water)
Deviations:
no
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
-
EC Number:
425-220-8
EC Name:
-
Cas Number:
5945-33-5
Molecular formula:
C39H34O8P2
IUPAC Name:
(1-methylethylidene)di-4,1-phenylenetetraphenyl diphosphate

Results and discussion

Dissociating properties:
no
Dissociation constant
Remarks on result:
other: CN-1985 was found not to dissociate below pH 11

Any other information on results incl. tables

No dissociation of CN-1985 was observed over the environmentally significant pH range. pKa is not provided in the report on this basis.

Applicant's summary and conclusion

Conclusions:
CN-1985 was found not to dissociate below pH 11. No dissociation was observed over the environmentally significant pH range. pKa is not provided in the report on this basis.
Executive summary:

A study was performed to investigate the dissociation constant of CN-1985. The method followed is described in the OECD Guidelines for the Testing of Chemicals (Method 112).

 

The dissociation constant was investigated by the spectrophotometric method, since it was noted that there was a difference between the ultraviolet/visible absorption spectra obtained in both acidic and neutral solutions and those obtained in basic solution.

This method was also considered to be the most appropriate to the investigations since the test substance is poorly soluble in water, and therefore the potentiometric method was not viable.

 

CN-1985 was found not to dissociate below pH 11. No dissociation was observed over the environmentally significant pH range.

pKa is not provided in the report on this basis.