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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Physical & Chemical properties

Dissociation constant

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Administrative data

Link to relevant study record(s)

Reference
Endpoint:
dissociation constant
Type of information:
calculation (if not (Q)SAR)
Remarks:
Migrated phrase: estimated by calculation
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Estimation of the dissociation constants was made by relevant computer-based estimation software.
Reason / purpose for cross-reference:
reference to same study
Qualifier:
no guideline available
Principles of method if other than guideline:
Estimation of the dissociation constants was made by relevant computer-based estimation software.
Dissociating properties:
no
Remarks:
At neutral pH >90% of the test substance is in a non-ionised form.
No.:
#1
pKa:
16.3
Remarks on result:
other: Acidic group: RRCHOH
No.:
#2
pKa:
16.9
Remarks on result:
other: Acidic group: RRCHOH
No.:
#3
pKa:
-0.12
Remarks on result:
other: Basic group: RCONHR
No.:
#4
pKa:
0.48
Remarks on result:
other: Basic group: RCONHR

Calculation of the dissociation constant (pKa)

From the structural formula of EA-3098, the following pKa values for acidic and basic groups in EA-3098 were calculated using the Perrin's calculation method.

 

Acidic groups:

RRCHOH: 16.3

RRCHOH: 16.9

 

Basic groups:

RCONHR: -0.12

RCONHR: 0.48

Based on these calculations, the aqueous phase used during the HPLC method (see partition coefficient study) was not buffered. At neutral pH >90% of the test substance is in a non-ionised form.

Conclusions:
From the structural formula of EA-3098, the pKa values for the basic groups were calculated to be 0.48 and -0.12 and the pKa values for the acidic groups were calculated to be 16.3 and 16.9.

At neutral pH, > 90% of the test substance is in a non-ionised form.
Executive summary:

Calculation of the dissociation constant (pKa)

From the structural formula of EA-3098, the following pKa values for acidic and basic groups in EA-3098 were calculated using the Perrin's calculation method (using computer estimation software: Software pKa: Pkalc version 5 (module in PALLAS version 3.0), an expert system for the calculation of pKa values).

 

Acidic groups:

RRCHOH: 16.3

RRCHOH: 16.9

 

Basic groups:

RCONHR: -0.12

RCONHR: 0.48

At neutral pH >90% of the test substance is in a non-ionised form.

Description of key information

From the structural formula of EA-3098, the pKa values for the basic groups were calculated to be 0.48 and -0.12 and the pKa values for the acidic groups were calculated to be 16.3 and 16.9.

At neutral pH, > 90% of the test substance is in a non-ionised form.

Key value for chemical safety assessment

Additional information

From the structural formula of EA-3098, the following pKa values for acidic and basic groups in EA-3098 were calculated using the Perrin's calculation method (using computer estimation software:Software pKa: Pkalc version 5 (module in PALLAS version 3.0), an expert system for the calculation of pKa values).

 

Acidic groups:

RRCHOH: 16.3

RRCHOH: 16.9

 

Basic groups:

RCONHR: -0.12

RCONHR: 0.48

At neutral pH >90% of the test substance is in a non-ionised form.