Trimethyloctadecylammonium bromide

Boiling point

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

boiling point

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Study period:

November 16, 2016

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Justification for type of information:

1. SOFTWARE: EPISUITE 4.1
2. MODEL : MPBPVP 1.43
3. SMILES USED AS INPUT FOR THE MODEL: [Br-].C[N+](C)(C)CCCCCCCCCCCCCCCCCC

Principles of method if other than guideline:

QSAR method
Smile notation: [Br-].C[N+](C)(C)CCCCCCCCCCCCCCCCCC
MPBPWIN estimates the normal boiling point using an adaptation of the Stein and Brown (1994) method which is an extension and refinement of the Joback method (Joback, 1982; Reid et al, 1987).  The Stein and Brown (1994) method is a group contribution QSAR (quantitative structure activity relationship) method that calculates boiling point (Tb) of a compound by adding group increment values according to the relationship:
Tb  =  198.2  + Σ( ni * gi )
where  gi  is a group increment value and  ni  is the number of times the group occurs in the compound.  The resulting  Tb  (deg K) is then corrected by one of the following equations:
Tb (corr)  =  Tb  -  94.84  +  0.5577 Tb  -  0.0007705 (Tb)2   [Tb <= 700 K]
Tb (corr)  =  Tb  + 282.7  -  0.5209 Tb     [Tb > 700 K]
The Stein and Brown (1994) method was developed using a training dataset of boiling points for 4426 diverse organic compounds collected from the Aldrich Handbook (Aldrich, 1990).
MPBPWIN incorporates additional extensions to Stein and Brown Method such as (1) new group contributions missing from Brown and Stein (e.g. thiophosphorus [P=S], quaternary ammonium) and (2) correction factors for specific types of compounds (e.g. amino acids, various aromatic nitrogen rings, and phosphates). 

Estimation Accuracy
The Stein and Brown method was derived from a training set of 4426 diverse organic compounds with following reported statistical accuracy (Stein and Brown, 1994):
 Average absolute error = 15.5 deg Kelvin
 Standard deviation = 24.6 deg Kelvin
 Average error = 3.2%
It was then validated on a dataset of 6584 compounds collected from HODOC (1990) (compounds not used in the training set) with the following statistical accuracy (Stein and Brown, 1994):
 Average absolute error = 20.4 deg Kelvin
 Standard deviation = 38.1 deg Kelvin
 Average error = 4.3%
The training and validation sets were not available.  However, a test set of 5890 compounds with available normal boiling points was collected from the PHYSPROP Database that is included with the EPI Suite.  Various compounds having boiling points were excluded (most inorganic compounds, compounds using reduced pressures).

GLP compliance:

no

Boiling pt.:

ca. 543.31 °C

Remarks on result:

other: QSAR method

Remarks:

estimated value

Conclusions:

The estimated boiling point, calculated using EpiSuite (MPBPWIN program), is 543.31 °C.

Executive summary:

Method

The boiling point as been estimated using the MPBPWIN program of EpiSuite.

Conclusion

The estimated boiling point is 543.31 °C.

Reference 2

Endpoint:

boiling point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

December 09, 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Qualifier:

according to guideline

Guideline:

other: ASTM E 794-95

GLP compliance:

no

Type of method:

differential scanning calorimetry

Boiling pt.:

> 400 °C

Remarks on result:

other: no boiling point observed in the test window (0 - 400 °C)

Conclusions:

Till a temperature of 400 °C the test substance doesn't boil.

Executive summary:

Method

The test item boiling point was evaluated using the Differential Scanning Calorimetry (DSC) according to the ASTM E 794 -95.

Conclusion

Till a temperature of 400 °C the test substance doesn't boil.

Description of key information

Boiling point (experimental) > 400 °C

Estimated boiling point (EPISUITE) = 543.31 °C

Key value for chemical safety assessment

Boiling point at 101 325 Pa:

543.31 °C

Additional information

In the temperature window (0 -400 °C) used in DSC method, described in the ASTM E 794 -95 guideline, the test substance doesn't boil. In conclusion the boiling temperature is > 400 °C. To support this result the boiling point was estimated using the MPBPWIN program of EpiSuite, and the value obtained is 543.31 °C.

The adequacy of the method of estimation has been reinforced by the comparison between the experimental melting point , whose value is 267.82 °C, and the estimated melting point , calculated bt the EpiSuite program 4.1(MPBPWIN), with a value of 232.83 °C.

The two temperature are comparable so it is supposed that the QSAR method used is adequate.