α-phenyl-1H-benzimidazole-2-methanol

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:

07 June 2018 to 10 July 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Study was conducted in accordance with international guidelines and in accordance with GLP.

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

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7200 (Melting Point / Melting Range)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Date of Inspection: 18 July 2017 - 20 July 2017 Date on Certfiicate: 28 November 2017

Type of method:

differential scanning calorimetry

Key result

Melting / freezing pt.:

ca. 176 °C

Decomposition:

yes

Decomp. temp.:

ca. 176 °C

The thermographic data fro the preliminary screen and determinations 1 to 4 are shown in the following tables:

Table 2: Thermographic Data - Preliminary Screen

Thermal Event	Interpretation	Temperature
		°C	K
Endotherm	Onset of melting	202.3	475.5
Endotherm (left limit)	Melting of decomposition product (see Section 4.2.5)	From ~220	From ~493

After heating to 400  °C, the crucible had lost 57% of the original mass.

The residue in the crucible was observed to be a shiny black stain.

Table 3: Thermographic Data - Determinations 1 to 4

Thermal Event	Interpretation	Temperature
		Determination 1		Determination 2		Determination 3		Determination 4
		°C	K	°C	K	°C	K	°C	K
Endotherm (left limit)	Start of melting with decomposition	179.7	452.9	176.5	449.7	177.7	450.8	176.2	449.3

After heating to 220 °C, the crucibles had lost an average of 16% of their original mass.
The residue in the crucibles were observed to be shiny dark brown solid around the periphery.

Overall Result: Melting with decomposition from approximately 176 °C (449 K)

Visual Method - Metal Block

In support of the DSC determinations, a visual determination was performed using a metal block apparatus. Sample observations and temperatures are summarized in the following table:

Table 4: Visual Evaluation

Temperature (°C)	Observation
20	Test item is a light brown powder
190	Light brown powder. Small droplets beginning to form
195	No change
200	Test item starting to darken with lots of small droplets
202	Shrinkage point. Test item is a dark brown/black solid
205	Test item completely melted. Dark red/brown liquid
207	Test item has solidified to a dark red/brown solid
210	Test item lightened in colour to red/orange solid
230	Test item liquified to dark red/brown liquid
240	No change
260	Test item is dark red/brown solid

Result: Melting with decomposition from approximately 190 °C (463 K).

On heating in determinations 1 to 4, the broad melting endotherm with the resultant dark brown residue was indicative of melting with decomposition. This was affirmed in the visual determination with the test item melting to a dark red/brown liquid.

The overall result reported has been derived from the left limit temperature of the integrated baseline. The lowest temperature of the four determinations has been reported.

Similar thermograms were obtained under air and nitrogen atmospheres indicating thermal decomposition.

Conclusions:

The test item was determined to melt with decomposition from approximately 176°C (449 K).

Executive summary:

The determination of melting point was carried out by differential scanning calorimetry, using a procedure designed to be compatible with Methods A.1 Melting/Freezing Temperature, Method 102 of the OECD Guidelines for the Testing of Chemicals and Methods 830.7200 of the OCSPP Guidelines.

The test item was determined to melt with decomposition from approximately 176 °C

Description of key information

The test item was determined to melt with decomposition from approximately 176 °C

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

176 °C

Additional information

The determination of melting point was carried out by differential scanning calorimetry, using a procedure designed to be compatible with Methods A.1 Melting/Freezing Temperature, Method 102 of the OECD Guidelines for the Testing of Chemicals and Methods 830.7200 of the OCSPP Guidelines.

The test item was determined to melt with decomposition from approximately 176 °C. As the substance begins to melt (with decomposition) from this temperature, it is selected as the key value for chemical safety assessment.