N,N-dimethyloctadecylamine N-oxide

Melting point / freezing point

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Qualifier:

no guideline followed

Principles of method if other than guideline:

The amine oxides were synthesised by oxidation of the corresponding trialkylamine with H2O2. After oxidation and isolation the products were thoroughly dried by azeotropic distillation with benzene and toluene followed by multiple crystallisations (4-5 times) from dry Me2CO and dried over P4O10 in a high vacuum. The purity was checked by TLC and IR spectra.

GLP compliance:

no

Type of method:

other: method not specified, however a capllary method was used for shorter chain length amine oxides

Melting / freezing pt.:

>= 133 - <= 136 °C

Atm. press.:

ca. 1 013 hPa

Remarks on result:

other: C10 Amine Oxides

Melting / freezing pt.:

>= 130 - <= 134 °C

Atm. press.:

ca. 1 013 hPa

Remarks on result:

other: C12 Amine Oxides

Melting / freezing pt.:

>= 125 - <= 129 °C

Atm. press.:

ca. 1 013 hPa

Remarks on result:

other: C14 Amine Oxides

Melting / freezing pt.:

>= 126 - <= 130 °C

Atm. press.:

ca. 1 013 hPa

Remarks on result:

other: C16 Amine Oxide

Aliphatic Amine Oxides undergo thermal decomposition between 90 and 200°C, and Cope elimination in the temperature range 150-200° C (formation of an olefin and a hydroxylamine by pyrolysis of an AO). As a consequence, melting is likely to be accompanied by decomposition.

Conclusions:

A study is described in the literature [Devinsky et al 1985] where the authors measured the melting points of the pure alkyl dimethylamine oxide constituents of the substance. The melting points ranged from 126-130 °C for C16 amine oxide to 133-136 °C for C10 amine oxide. Regarding these tempereature range, Aliphatic Amine Oxides undergo thermal decomposition between 90 and 200°C, and Cope elimination in the temperature range 150-200° C (formation of an olefin and a hydroxylamine by pyrolysis of an AO). As a consequence, melting is likely to be accompanied by decomposition.

Executive summary:

A study is described in the literature [Devinsky et al 1985] where the authors measured the melting points of the pure alkyl dimethylamine oxide constituents of the substance. The melting points ranged from 126-130 °C for C16 amine oxide to 133-136 °C for C10 amine oxide. Regarding these tempereature range, Aliphatic Amine Oxides undergo thermal decomposition between 90 and 200°C, and Cope elimination in the temperature range 150-200° C (formation of an olefin and a hydroxylamine by pyrolysis of an AO). As a consequence, melting is likely to be accompanied by decomposition.

Reference 2

Endpoint:

melting point/freezing point

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

1. SOFTWARE AND MODEL
OPERA-Model for Melting Point
OPERA v1.5

2. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
SMILES : C(CCCCCCCCCCCCCCC)CC[N+](C)(C)[O-]
NAME : N,N-Dimethyl-1-octadecanamine-N-oxide
CAS Number : 2571-88-2

3. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
See QMRF_MeltingPoint_C18AmineOxide-OPERA_Q17-11-0015

4. APPLICABILITY DOMAIN
See QMRF_MeltingPoint_C18AmineOxide-OPERA_Q17-11-0015

Guideline:

other: REACH guidance on QSARs R.6

Principles of method if other than guideline:

- Software tool(s) used including version: OPERA-model for Melting Point
- Model(s) used: v1.5 (2016)
- Model description: see field 'Justification for type of information"
- Justification of QSAR prediction: see field 'Attached justification'

GLP compliance:

no

Specific details on test material used for the study:

SMILES : C(CCCCCCCCCCCCCCC)CC[N+](C)(C)[O-]

Key result

Melting / freezing pt.:

ca. 147 °C

Remarks on result:

other: QSAR predicted value

OPERA predicted that N,N-Dimethyl-1-octadecanamine-N-oxideh has a Melting point = 147 °C

Conclusions:

OPERA predicted that N,N-Dimethyl-1-octadecanamine-N-oxideh has a Melting point = 147 °C

Executive summary:

OPERA predicted that N,N-Dimethyl-1-octadecanamine-N-oxideh has a Melting point = 147 °C

Reference 3

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

2018-2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7200 (Melting Point / Melting Range)

GLP compliance:

no

Type of method:

capillary method

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 8110028
- Expiration date of the lot/batch :-
- Manufacturing date: -
- Storage condition: Room temperature, not above 35 °C

Key result

Melting / freezing pt.:

> -1 - < 1 °C

Atm. press.:

1 005 hPa

Decomposition:

yes

Conclusions:

A study is conducted according to OECD TG 102, EU Method A.1, in order to determine the rmeltingpoint of the test item. On the basis of QSAR approach a value of 147°C is expected. The study record will be updated as soon as the results will become available (January 2019).

Executive summary:

A study is currently conducted according to OECD TG 102, EU Method A.1, in order to determine the rmeltingpoint of the test item. On the basis of C12 -18 Amine Oxide data, the melting point range is between 1°C to +1°C at atmospheric pressure.

.

Description of key information

A study is conducted according to OECD TG 102, EU Method A.1, in order to determine the melting point of N,N-Dimethyl-1-octadecanamine-N-oxide. The range of melting point is -1°C to +1°C at atmospheric condition. However, this test is not on the substance but on mixture (amine oxides are procuded and transported in aqueous solutions thata are 25 -35% concentration) and it cannot be representative of the substance melting point.

Two other studies, based one on the QSAR approach (OPERA) and the other on the bibliographic source, indicate that the Amine Oxides melting points is ranged from 126-136 °C and N,N-Dimethyl-1-octadecanamine-N-oxide has a Melting Point: of 147 °C.

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

147 °C