7,7-dimethyl-3-oxa-6-azaoctan-1-ol

Melting point / freezing point

Link to relevant study record(s)

Reference

Endpoint:

melting point/freezing point

Type of information:

(Q)SAR

Adequacy of study:

key study

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

Qualifier:

according to guideline

Guideline:

other: REACH Guidance on QSAR's R.6

Principles of method if other than guideline:

MPBPWIN estimates melting point by two different methods. The first is an adaptation of the Joback group contribution method for melting point (Joback, 1982; Reid et al; 1987) and the second is a simple Gold and Ogle method suggested by Lyman (1985) - see references below. MPBPWIN averages the adapted Joback and the Gold and Ogle estimates and reports the average estimate as well as both individual estimates.
Joback, K.G.(1982) A Unified Approach to Physical Property Estimation Using Multivariate Statistical Techniques. Stevens Institute of Technology, submitted to the Dept. of Chem. Eng. for M.S. Degree at the Massachusetts Institute of Technology in June 1984. (see also: Reid et al., 1987).
Gold, P.I. and Ogle, G.J. 1969. Estimating thermophysical properties of liquids. Part 4 - Boiling, freezing and triple-point temperatures. Chem. Eng. 76: 119

Specific details on test material used for the study:

C(C)(C)NCCOCCO

Key result

Melting / freezing pt.:

17.21 °C

Melting Point: 16.20 ºC (Adapted Joback Method)

Melting Point:  18.21 ºC (Gold and Ogle Method)

Mean Melting Point: 17.21 ºC (Joback; Gold, Ogle Methods)

Selected Melting Point: 17.21 ºC (Mean Value)

MPBPWIN averages the adapted Joback and the Gold and Ogle estimates and reports the average estimate as well as both individual estimates.

MPBPWIN then goes one step further. It reports a "suggested" melting point (MP) that is based upon the two individual estimates and several criteria. First, MPBPWIN looks at the difference between the two estimates. If the difference is small (< 30 K), the suggested MP is simply the average. When this criteria fails (which occurs quite often), MPBPWIN examines the structure type and the magnitude of the difference. It then decides which estimate is more likely to be accurate and "weights" the suggested MP accordingly. For example, when MPBPWIN detects an amino-acid structure, it uses a 75% weighting factor for the higher estimate and 25% for the lower estimate to derive the suggested MP. Weighting factors in MPBPWIN were approximated through observation of estimated versus experimental MP.

Conclusions:

The melting point was predicted using MPBPWIN (v1.43). The model uses two estimation methods and reoirts the average estimate.
The melting point was predicted to be 17.21ºC.

Executive summary:

The melting point was predicted using the EPISuite (v4.11) MPBPWIN (v1.43) programme for the substance. The molecular structure (SMILE notation) was used as the input, along with the experimentally measured boiling point.

The melting point was predicted to be 17.21ºC.

Description of key information

QSAR (REACH guidance on QSARs R.6): EPISuite v 4.11; MPBPWIN v1.43: mean melting point: 17.21ºC

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

17.21 °C