Platinum(IV) aqua hydroxo nitrato complexes

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:

15 September 2016 to 23 September 2016

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:

yes (incl. QA statement)

Type of method:

differential scanning calorimetry

Key result

Decomposition:

yes

Decomp. temp.:

ca. 100 °C

The DSC measurement in an aluminium crucible with a hole showed a multistage endothermal effect in the temperature range of 110 – 460 °C. After the measurement, the test item was discoloured to black. The mass loss after the DSC measurement amounted to 32 %.

An additional measurement with the capillary method was performed in order to clarify the results. A high heating rate of 10 K/min was chosen and therefore the absolute temperature values derived with the capillary method are not as accurate as the DSC results. Under consideration of the results from the DSC measurement and the capillary method it was concluded that the test item had no melting point and no boiling point at atmospheric conditions.

Table1: DSC measurements

No.

Test item / mg

Starting temperature / °C

Final test temperature / °C

Temperature range / °C

Crucible

Observations after the measurement

1

25.36

25

500

100 – 460 (endothermal, multistage)

Aluminium with a hole

Test item was black after the measurement; mass loss: 32 %

 

 

Table2: Results of the capillary method

No.	Set point / °C	Heating rate / K/min	End point / °C	Remarks
1	80	10	300	Approx. 101 °C:  test item became pale Approx. 204 °C:  test item glittered and started to melt Approx. 241 °C:  test item was not completely melted but discoloured to rust-brown Approx. 269 °C:  test item was a grey-black melt Approx. 300 °C:  no further discolouration observed

Conclusions:

The test item had no melting point at atmospheric conditions. Decomposition started at approximately 100 °C.

Executive summary:

This is a GLP compliant study following OECD guideline 102 and is considered suitable for use as the key study for this endpoint. The melting point / melting range were determined by differential scanning calorimetry (DSC) and capillary tube in a metal block.

The test item had no melting point at atmospheric conditions. Decomposition started at approximately 100 °C.

Description of key information

The test item had no melting point at atmospheric conditions. Decomposition started at approximately 100°C.

Additional information

A GLP compliant study following OECD guideline 102 was performed to determine melting point of platinum dinitrate (Nau 2016). It was concluded that the test item had no melting point at atmospheric conditions as decomposition started at approximately 100°C.