Reaction mass of 6-amino-2-anilino-4-methyl-5-{(E)-[4-nitro-2-(substituted)phenyl]diazenyl}nicotinonitrile and 2-amino-6-anilino-4-methyl-5-{(E)-[4-nitro-2-(substituted)phenyl]diazenyl}heteromonocyclic nitrile

Melting point / freezing point

Link to relevant study record(s)

Reference

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

12 October 2011- 31 January 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study has been performed according to OECD and EC guidelines and according to the principles of GLP.

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Version / remarks:

(2008)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Version / remarks:

(1995)

Deviations:

no

GLP compliance:

yes

Type of method:

thermal analysis

Melting / freezing pt.:

250 °C

Decomposition:

yes

Remarks:

decomposition during melting

Melting / freezing pt.:

523 K

TGA preliminary test:

From 300 °C upwards the weight of the sample decreased significantly. At 407 °C the sample weight had decreased by 25 %. After the experiment, a black molten residue remained in the sample container (original colour: red). The change of the colour indicated reaction and/or decomposition of the test substance. The TGA-curve of the test substance is shown in the attached document.

 

DSC Main experiments:

Experiment 1: Two endothermic peaks between 225 °C and 275 °C were observed. The extrapolated onset temperature of the first peak was 249.51 °C. The effects were most likely obtained due to melting or reaction and/or decomposition of the test substance. An exothermic peak between 275 °C and 400 °C was observed. This effect was due to reaction and/or decomposition of the test substance. After the experiment, a black molten residue remained in the sample container. Figure 5 (see attached document) shows the DSC-curves obtained.

 

Experiment 2: To investigate the peaks between 225 °C and 275 °C a lower heating rate of 5 °C/minute was applied in the second experiment. The extrapolated onset temperature of the first peak was 252.35 °C (not used for determination of the melting point since it was obtained with a low heating rate). Since the start of the effect occurred at the same temperature it was concluded that the effect was due to melting of the test substance. An exothermic effect started at 275 °C. This effect was due to reaction and/or decomposition of the test substance. After the experiment, a dark purple/blue molten residue remained in the sample container. Figure 6 (see attached document) shows the DSC-curves obtained.

 

Experiment 3: To investigate the melting peak the third experiment was stopped directly after the endothermic effect. The extrapolated onset temperature of the first (melting) peak was 249.85 °C. After the experiment, a dark purple/blue molten residue remained in the sample container. It indicated that reaction and/or decomposition occurred during and/or immediately after melting. Figure 7 (see attached document) shows the DSC-curves obtained.

 

Experiment 4: To further investigate the melting peak the fourth experiment was stopped directly after melting. After the experiment, a brown coagulated residue remained in the sample container. It demonstrated that reaction and/or decomposition occurred during melting. Figure 8 (see attached document) shows the DSC-curves obtained.

Conclusions:

The melting temperature of FAT 41043/A is 250 °C. Reaction/decomposition during melting.

Description of key information

Melting at 250 °C (EC A.1, OECD 102: DSC)

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

250 °C

Additional information

Reaction/decomposition during melting.