2,2'-bipyridyl

Boiling point

Link to relevant study record(s)

Reference

Endpoint:

boiling point

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: According to OECD guideline 103 without deviation

Qualifier:

according to guideline

Guideline:

OECD Guideline 103 (Boiling point/boiling range)

Deviations:

no

Principles of method if other than guideline:

The above-mentioned guidelines contain several different methods for the determination of the boiling point / boiling range. These methods include thermal analysis using a calorimeter and visual tests (e.g. capillary test). During the present study the thermal analysis was used.

A phase transformation, e.g. melting or evaporation, or a reaction, e.g. dissociation, usually is associated with a heat effect. In the calorimeter, two identical aluminium sample containers, one filled with the test item and the other empty (used as a reference), are heated at a constant rate. During the experiment, the heat effect, i.e. the difference in heat flow, between the sample container and the reference container is registered.

A preliminary test was conducted in which a test item amount of 3.24 mg was heated up from 25 °C to 400 °C at a rate of 20 °C/min. The
quantities of heat absorbed or released were measured and recorded. Before and after the test, the weight and the appearance of the sample were determined.

In the main test in the temperature range investigated, a peak was observed from which boiling of the sample could be deduced, the thermal analysis was repeated in the immediate vicinity of the peak temperature with the temperature rise adjusted to 10 °C/min. For the actual determination of the boiling point, 4.63 mg and 6.81 mg, respectively, of the test item were heated up from 240 °C to 310 °C. Before and after the test, the weight and the appearance of the samples were determined.

GLP compliance:

no

Type of method:

differential scanning calorimetry

Boiling pt.:

272.2 °C

Atm. press.:

99 kPa

Boiling pt.:

545.4 K

Atm. press.:

99 kPa

The DSC-curve of the preliminary test (heating rate of 20 °C/min from 25 °C to 400 °C) showed a first endothermic heat effect, the melting, at about 70.8 °C (see Harlan Laboratories study D01028). A second endothermic heat effect, the boiling, was detected at about 272.8 °C. After the experiment, the sample had all of its mass and no residue remained in the sample cup.

In order to determine the boiling point more precisely, further DSC-runs were recorded between 240 °C and 310 °C with a heating rate of 10 °C/min. During these runs, the boiling point was determined to be 272.1 °C and 272.2 °C. The samples lost less than 4% of their mass, respectively. After the measurements no residue remained in the sample cups.

Conclusions:

The boiling point of CA3610A was determined to be 272.2 °C, which is equal to 545.4 K.
The estimated accuracy is ± 0.5 K.
This result was obtained using Differential Scanning Calorimetry (Thermal Analysis) method.
The atmospheric pressure during the measurements was 99.0 kPa.

Description of key information

The boiling point of CA3610A was determined to be 272.2 °C (Kuehne 2010), which is equal to 545.4 K.
The estimated accuracy is ± 0.5 K.
This result was obtained using Differential Scanning Calorimetry (Thermal Analysis) method.
The atmospheric pressure during the measurements was 99.0 kPa.

Key value for chemical safety assessment

Boiling point at 101 325 Pa:

272.2 °C

Additional information

A very large body of experimental data exists in the literature for boiling point. The range of boiling points observed likely reflects experimental error, as well as the larger effect of different purities. The boiling point deemed best for classification and risk assessment purposes is the key study. This is in good agreement with existing literature.