Pyridinium dichromate

Melting point / freezing point

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

2009-03-24

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Deviations:

no

GLP compliance:

no

Type of method:

differential scanning calorimetry

Key result

Melting / freezing pt.:

> 142.9 - < 161.7 °C

Decomposition:

yes

Decomp. temp.:

> 162.2 - < 290.2 °C

Sublimation:

no

Table 1. Results from the DSC measurement

Thermal Event	EXO or ENDO	Onset Temperature [°C]	Final Temperature [°C]	Peak Temperature [°C]	Heat of Reaction [J/G]	Comment
1	ENDO	142.9	161.7	NA	-131.85	Slow initial onset, then rapid adsorption and short duration
2	EXO	162.2	290.2	NA	1685.96	Initially slow onset, then rapid decomposition.

 

Conclusions:

The melting point of the test item was determined with DSC to be in the range of 142.9 - 161.7 °C followed by a decomposition in the range of 162.2 - 290.2 °C.

Executive summary:

According to OECD 102 and EU Method A.1 the melting point of the test item was determined using differential scanning calorimetry (DSC) method. 11.3 mg of the test item were weighed in and heated with a heating rate of 5 °C/min up to 400 °C. Two peaks were observed - an endothermic peak at 143 - 162 °C and an exothermic peak at 162 - 290 °C. The melting point of the test item was determined with DSC to be in the range of 142.9 - 161.7 °C followed by a decomposition in the range of 162.2 - 290.2 °C.

Reference 2

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009-04-01

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Deviations:

no

GLP compliance:

no

Type of method:

differential scanning calorimetry

Key result

Melting / freezing pt.:

154.2 °C

Decomposition:

yes

Decomp. temp.:

ca. 246.1 °C

Sublimation:

no

Table 1. Results from the DSC measurement

Thermal Event	EXO or ENDO	Onset Temperature [°C]	Final Temperature [°C]	Peak Temperature [°C]	Heat of Reaction [J/G]	Comment
1	ENDO	140.1	164.5	154.2	-65.53	Rapid onset, short duration
2	EXO	211.9	318.8	246.1	1105.51	Initially slow onset, at 220 °C becomes rapid.

 

Conclusions:

The melting point of the test item was determined with DSC to be 154.2 °C followed by a rapid decomposition at ca. 246.1 °C.

Executive summary:

According to OECD 102 and EU Method A.1 the melting point of the test item was determined using differential scanning calorimetry (DSC) method. 5.1 mg of the test item were weighed in 40 µL disposable crucible and heated with a heating rate of 5 °C/min up to 400 °C. Two peaks were observed - an endothermic peak at 140 - 165 °C and an exothermic peak at 212 - 319 °C. The melting point of the test item was determined with DSC to be 154.2 °C followed by a rapid decomposition at ca. 246.1 °C.

Description of key information

The melting point of the test item was determined with DSC to be 154.2 °C followed by a rapid decomposition at ca. 246.1 °C (reference 4.2-1).

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

154.2 °C

Additional information

Key study

According to OECD 102 and EU Method A.1 the melting point of the test item was determined using differential scanning calorimetry (DSC) method. 5.1 mg of the test item were weighed in 40 µL disposable crucible and heated with a heating rate of 5 °C/min up to 400 °C. Two peaks were observed - an endothermic peak at 140 - 165 °C and an exothermic peak at 212 - 319 °C. The melting point of the test item was determined with DSC to be 154.2 °C followed by a rapid decomposition at ca. 246.1 °C (reference 4.2-1).

Supporting study

In a supporting study performed cccording to OECD 102 and EU Method A.1 the melting point of the test item was determined using differential scanning calorimetry (DSC) method. 11.3 mg of the test item were weighed in and heated with a heating rate of 5 °C/min up to 400 °C. Two peaks were observed - an endothermic peak at 143 - 162 °C and an exothermic peak at 162 - 290 °C. The melting point of the test item was determined with DSC to be in the range of 142.9 - 161.7 °C followed by a decomposition in the range of 162.2 - 290.2 °C. No peak temprature was determined for the two observed effects but a general idea of the melting properties of the test item could be obtained from this measurement (reference 4.2-2).