N'-(1,3-dimethylbutylidene)-3-hydroxy-2-naphthohydrazide

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 November 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: Directive 92/69/EEC,A.1 (DSC method) (EEC publ. no L383, Dec 1992)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Version / remarks:

(1995)

Deviations:

no

GLP compliance:

yes

Type of method:

differential scanning calorimetry

Key result

Melting / freezing pt.:

150 °C

Remarks on result:

other: extrapolated onset temperature of the melting peak

Melting / freezing pt.:

423 K

Remarks on result:

other: extrapolated onset temperature of the melting peak

First experiment:

A sharp endothermic peak was observed between 141 and 172°C (414 - 445 K). This effect is probably caused by melting of the test substance. Above the melting peak, between 172 and 250°C (445 - 523 K) a small exothermic effect was observed. Another exothermic effect was observed at temperatures above 305°C (578 K). Both exothermic effects are probably caused by reaction and/or decomposition of the test substance. After the experiment the sample had lost 1.63 mg (34%) of its mass. The sample had been molten and had a dark brown colour (original colour: white).

Second, third and fourth experiments:

The endothermic melting peaks were observed between 141 and 161°C (414 - 434 K). The small exothermic effect was observed above 177°C (450 K) during the third experiment and above 180°C (453 K) during the fourth experiment. These effects probably indicate reaction or decomposition of the test substance. After the second experiment the sample had been molten and had a yellow colour; no significant mass change was observed. After the third and the fourth experiment the sample had lost 0.16 mg (6%) and 0.88 mg (29%), respectively. In both cases the sample had been molten and had a dark brown colour.

The melting point of the substance was evaluated from the four DSC-curves as the extrapolated onset of the melting peak, i.e. 151°C (424 K), 150°C (423 K), 150°C (423 K) and 150°C (423 K), respectively.

Graphs of experiments are attached in the illustration.

Conclusions:

The melting point of the test substance was determined with DSC to be 150°C (423 K). Reaction or decomposition of the test substance was observed at temperatures just above the melting point.

Description of key information

The melting point of BMH is 150°C (423 K (EC A.1, OECD 102: DSC) 

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

150 °C

Additional information

Reaction or decomposition was observed at temperatures just above the melting point.