N,N'-[bicyclo[2.2.1]heptane-2,6-diylbis(methylene)]bis(2-cyanoacetamide)

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

Study period:

QSAR Report 27th March 2020

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model, but not (completely) falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

SOFTWARE / MODEL (incl. version number)
Mpbpwin v1.43 US EPA EPI SUITE Software

SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
C1(CC2C(CC1C2)CNC(=O)(CC(#N)))CNC(=O)(CC(#N))

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
- Defined endpoint: Melting Point
- Unambiguous algorithm: Comination of two methods; Joback Group contribution method (Joback 1982; Reid et al. 1987) and Gold and Ogle method (Lyman 1985). An extension the origional Joback method which includes groups adapted by Stein and Brown for Boiling point. Melting Point correction factors are used in specific cases, but were not neccessary for this prediction. The Gold and Ogle method related meling point (Tm) to boiling point (tb) as follows:
Tm = 0.5839 Tb. Units in K
The use of an average of the two predictions provides a more reliable estimate of the melting point of a substance. However, using the MPBPWIN tool, the difference between the two estimates is taken into consideration. If the difference is small, (< 30K) the suggested MP is the average. If the difference is large, the structure type is examined and the estimate uses the method which is deemed more accurate. The tool weights the MP accordingly.
- Defined domain of applicability:
The current applicability of the MPBPWIN methodology is best described by its accuracy in predicting melting point.  The complete dataset with experimental values and estimates is available via Internet download http://esc.syrres.com/interkow/EpiSuiteData.htm
- Appropriate measures of goodness-of-fit and robustness and predictivity:
For the current EPI Suite, the accuracy of the "suggested" MPBPWIN melting point estimate was tested on a large dataset of 10,051 compounds containing a diverse mix of simple, moderate and very complex structural compounds (includes many pesticides and pharmaceutical compounds).  The dataset was taken from the PHYSPROP Database used by the EPI Suite.  Compounds having "decompose" designations with MP values were excluded.  The complete dataset with experimental values and estimates is available at http://esc.syrres.com/interkow/EpiSuiteData.htm
Substructure searchable data set of melting point test is available at http://esc.syrres.com/interkow/EpiSuiteData_ISIS_SDF.htm
- Mechanistic interpretation:


5. APPLICABILITY DOMAIN

- Descriptor domain:
- Structural and mechanistic domains:
The functional groups and structural featues are present in molecules included in the training set. However, fragment coefficients were not found.
- Similarity with analogues in the training set:
No similarity coefficients were calculated. Hence designation of the reliability at Klimmisch score 2.
- Other considerations (as appropriate):

The PHYSPROP Database contains 3246 compounds designated as liquids or having melting point less than 25oC.  In addition, it contains 8225  compounds with melting points greater than 25oC. For these datasets, MPBPWIN  predicts the following (assuming compounds with MP of 25oC or less are liquids & compounds with 25oC or greater MP are solids):

For 8225 solid compounds - MPBPWIN predicts 93% of the compounds will be solids
For 3246 liquid compounds -  MPBPWIN predicts 70% of the compounds will be liquids
For all 11471 compounds - MPBPWIN correctly predicts the physical state of 86% of all compounds.

Qualifier:

no guideline available

Principles of method if other than guideline:

Method follows European Chemicals Agency Practical Guide on How to Use and Report QSARs Version 3.1
Estimated data are obtained from a reliable (Q)SAR program developed and validated by the United States Environmental Protection Agency (U.S. EPA). This program is included in the OECD (Q)SAR Toolbox for use in filling REACH datagaps

GLP compliance:

no

Specific details on test material used for the study:

SMILES : C1(CC2C(CC1C2)CNC(=O)(CC(#N)))CNC(=O)(CC(#N))
CHEM : NBDA-Cyanoacetamide
MOL FOR: C15 H20 N4 O2

Key result

Melting / freezing pt.:

240.75 °C

Conclusions:

Selected melting point based on the combination of Joback, Gold and Ogle models is 240.75 degrees C.

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

240.75 °C