Registration Dossier

Administrative data

Endpoint:
melting point/freezing point
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report date:
2018

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 102 (Melting point / Melting Range)
Version / remarks:
1995
GLP compliance:
not specified
Type of method:
differential scanning calorimetry

Test material

Constituent 1
Chemical structure
Reference substance name:
Dipotassium dihydrogen 4-[5-[3-carboxylato-5-hydroxy-1-(4-sulphonatophenyl)-1H-pyrazol-4-yl]penta-2,4-dienylidene]-4,5-dihydro-5-oxo-1-(4-sulphonatophenyl)-1H-pyrazole-3-carboxylate
EC Number:
257-479-6
EC Name:
Dipotassium dihydrogen 4-[5-[3-carboxylato-5-hydroxy-1-(4-sulphonatophenyl)-1H-pyrazol-4-yl]penta-2,4-dienylidene]-4,5-dihydro-5-oxo-1-(4-sulphonatophenyl)-1H-pyrazole-3-carboxylate
Cas Number:
51858-17-4
Molecular formula:
C25H16N4O12S2.2K
IUPAC Name:
dipotassium dihydrogen 4-[(1E,3E)-5-[(4E)-3-carboxy-5-oxo-1-(4-sulfophenyl)-4,5-dihydro-1H-pyrazol-4-ylidene]penta-1,3-dien-1-yl]-5-hydroxy-1-(4-sulfophenyl)-1H-pyrazole-3-carboxylate
Test material form:
solid: crystalline

Results and discussion

Melting / freezing point
Decomposition:
yes
Remarks:
The substance decomposes before melting.
Decomp. temp.:
> 280 °C
Remarks on result:
not determinable

Any other information on results incl. tables

1. Endothermic effect at 50 - 200 °C:

- Peak 92.95 °C

- Enthalpy 326.68 J/g (release of water)

2. Exothermic effect at 280 - 420 °C:

- Peak 406.78 °C

- Enthalpy -342.07 J/g (decomposition)

Applicant's summary and conclusion

Conclusions:
The endothermic effect shown at the DSC spectrum is not the melting point of the substance but the boiling point of the solvent (water). The exothermic effect starts at 280 °C when the substance decomposes. Therefore, the substance decomposes before melting point.