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Physical & Chemical properties

Dissociation constant

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Endpoint:
dissociation constant
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: peer reviewed data base
Qualifier:
no guideline available
Principles of method if other than guideline:
Method: potentiometric
GLP compliance:
not specified
Dissociating properties:
yes
No.:
#1
pKa:
10.51
Temp.:
25 °C
No.:
#2
pKa:
9.81
Temp.:
25 °C
No.:
#3
pKa:
8.31
Temp.:
25 °C
No.:
#4
pKa:
5.52
Temp.:
25 °C
Results:
pK apparent    b1        b2         b3          b4 
10.51 9.81 8.31 5.52

Temperature 25°C
Solvent H2O / various solvents
Ratio of solvents 0.1 M
Method potentiometric
Endpoint:
dissociation constant
Type of information:
calculation (if not (Q)SAR)
Remarks:
Migrated phrase: estimated by calculation
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: accepted calculation method
Qualifier:
no guideline required
Principles of method if other than guideline:
Calculation of pKa using SPARC v4.5
GLP compliance:
no
Dissociating properties:
yes
No.:
#1
pKa:
4.87
Temp.:
25 °C
Remarks on result:
other: macroscopic pKa
No.:
#2
pKa:
7.99
Temp.:
25 °C
Remarks on result:
other: macroscopic pKa
No.:
#3
pKa:
9.88
Temp.:
25 °C
Remarks on result:
other: macroscopic pKa
No.:
#4
pKa:
10.69
Temp.:
25 °C
Remarks on result:
other: macroscopic pKa

Seven species:

1: NCCCNCCNCCCN

2: [N+1]CCCNCCNCCCN

3: [N+1]CCC[N+1]CC[N+1]CCC[N+1]

4: [N+1]CCC[N+1]CCNCCC[N+1]

5: [N+1]CCCNCC[N+1]CCCN

6: [N+1]CCCNCCNCCC[N+1]

7: NCCC[N+1]CCNCCCN

The macroscopic pKa estimates were generated from the crossing of the charge curves.

Description of key information

N,N'-Bis(3-aminopropyl)ethylendiamine shows 4 dissociation constants at 25°C: 
#1 10.51
#2 9.81
#3 8.31
#4 5.52

Key value for chemical safety assessment

Additional information

N,N'-Bis(3-aminopropyl)ethylendiamine shows 4 dissociation constants which are consistenty reported in different literature sources.

The values derived from REAXYS, a peer reviewed data base, originates from an experimental study are in the range of (5.52 - 10.69) for the substance.