1,2,4-triazole-3-thiol

Boiling point

Administrative data

Endpoint:

boiling 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:

2019

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 103 (Boiling Point)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

differential scanning calorimetry

Test material

Test material information

Constituent 1

Reference substance name:

1,2,4-triazole-3-thiol

EC Number:

221-656-6

EC Name:

1,2,4-triazole-3-thiol

Cas Number:

3179-31-5

Molecular formula:

C2H3N3S

IUPAC Name:

4H-1,2,4-triazole-3-thiol

Test material form:

solid: crystalline

Results and discussion

Boiling point

Key result

Boiling pt.:

>= 231.22 - <= 323.92 °C

Decomposition:

yes

Decomp. temp.:

ca. 304.9 °C

Any other information on results incl. tables

Values DSC Test Item first determination

Results	Temperature[°C]	Heat flow
Beginning melting processBegin Peak max melting process End melting process Beginning boiling under decomposition Peak max boiling process Peak max decomposition End boiling under decomposition	186.53°C 220.95°C 231.22°C 231.22°C 285.89°C 304.76°C 323.92°C	18.42 mW 37.92 mW 19.03 mW 19.03 mW 23.27 mW 7.33 mW 15.80 mW

Values DSC Test Item second determination

Results	Temperature[°C]	Heat flow
Beginning melting processBegin Peak max melting process End melting process Beginning boiling under decomposition Peak max boiling process Peak max decomposition End boiling under decomposition	186.81°C 220.95°C 231.22°C 231.22°C 285.61°C 305.04°C 323.64°C	17.59 mW 37.33 mW 18.04 mW 18.04 mW 22.28 mW 5.39 mW 14.39 mW

1.1     Observations

Table8.5‑a      Values Observations

	Mass test item	Mass crucible (before measurement):	Mass crucible (after measurement):	Observations
First Measurement	4.83 mg	50.15 mg	47.28 mg	After the test the crucible was visually unchanged. Then the crucible was opened, the test item was yellow
Second Measurement	4.84 mg	50.10 mg	47.24 mg	After the test the crucible was visually unchanged

1.2     Interpretation of the measurements

Two DSC measurements were performed.

In both measurements two successive endothermic events were detected. Based on the observations of the pre-test, these can be identified as melting process.

 

Immediately afterwards, the baseline rose slowly and then fell to an exothermic event. According to observations in the pre-test and based on the appearance of the test item after determination, this can be interpreted as boiling under decomposition, evaluated with event marker function and will be given in range.

 

 

1.3     Presentation of results

For the calculation of the values of the mean and the standard deviation, only the second and third determination was taken into account.

Table8.7a       Results

Beginning melting process	in °C (event mark)	in K
1 determination	186.53	459.68
2 determination	186.81	459.96
Min	186.53	459.68
Peak max melting process	in °C (event mark)	in K
1 determination	220.95	494.10
2 determination	220.95	494.10
Mean	220.95	494.10
SD	0.00	0.00
End melting process	in °C (event mark)	in K
1 determination	231.22	504.37
2 determination	231.22	504.37
Max	231.22	504.37
Beginning boiling under decomposition	in °C (event mark)	in K
1 determination	231.22	504.37
2 determination	231.22	504.37
Min	231.22	504.37
Peak max boiling process	in °C (event mark)	in K
1 determination	285.89	559.04
2 determination	285.61	558.76
Mean	285.75	558.90
SD	0.20	0.20
Peak max decomposition	in °C (event mark)	in K
1 determination	304.76	577.91
2 determination	305.04	578.19
Mean	304.90	578.05
SD	0.20	0.20
End boiling under decomposition	in °C (event mark)	in K
1 determination	323.92	597.07
2 determination	323.64	596.79
Max	323.92	597.07

 

1.4     Validity

As decomposition was detected no validity criteria must be considered.

Applicant's summary and conclusion

Conclusions:

The determination of the boiling point 3-Mercapto-1,2,4-triazole was performed via DSC (differential scanning calorimetry).
In both measurements two successive endothermic events were detected. Based on the observations of the pre-test, they can be identified as melting process and will be given in a range:
From 186.53°C (459.68 K) to 231.22°C (504.37 K)

Afterwards, the Baseline increased and then fell off to an exothermic event. Based on the observations of the pre-test and the test item after the test, this event can be interpreted as boiling process under decomposition. This will be given in a range and were evaluated with event marker function.

The boiling process under decomposition should be stated as:

From 231.22°C (504.37 K) to 323.92°C (597.07 K)

With a Peak max (boiling) at 285.75 °C (558.90 K) ± 0.20
And a peak max (decomposition) at 304.90°C (578.05 K) ± 0.20


No observations were made which might cause doubts on the validity of the study out-come. Therefore, the result of the study is considered valid.

Executive summary:

The determination of the boiling pointof 3-Mercapto-1,2,4-triazole was performed via DSC (differential scanning calorimetry).

In both measurements two successive endothermic events were detected. Based on the observations of the pre-test, these can be identified as melting process and will be given in a range:

From 186.53°C (459.68 K) to 231.22°C (504.37 K)

 

Afterwards, the Baseline increased and then fell off to an exothermic event. Based on the observations of the pre-test and appearance of the test item after the test, this event can be interpreted as boiling process under decomposition. This will be given in a range and were evaluated with event marker function.

 

The boiling process under decomposition should be stated as:

 

From 231.22°C (504.37 K) to 323.92°C (597.07 K)

 

With a Peak max (boiling) at 285.75 °C(558.90 K) ± 0.20

And a peak max (decomposition) at 304.90°C (578.05 K) ± 0.20