4,4'-methylenebis(cyclohexylamine)

Adsorption / desorption

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

adsorption / desorption, other

Remarks:

calculation

Type of information:

calculation (if not (Q)SAR)

Remarks:

Migrated phrase: estimated by calculation

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Scientifically acceptable calculation method

Principles of method if other than guideline:

Calculation method determining the Koc for charged molecules

GLP compliance:

no

Type of method:

other: calculation of log Koc for ionized molecule

Media:

soil

Test temperature:

25 °C

Type:

log Koc

Value:

4.25

Temp.:

25 °C

Remarks on result:

other: pH 5 - 8

Type:

Koc

Value:

17 781 - 17 958

Temp.:

25 °C

Remarks on result:

other: pH 5 - 8

The data refer to the charged molecule.

 

pH-corrected Koc

pH 5: 17958

pH 7: 17941

pH 8: 17781

 

Reference 2

Endpoint:

adsorption / desorption

Remarks:

adsorption

Type of information:

calculation (if not (Q)SAR)

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Accepted calculation method

Justification for type of information:

Estimation Programs Interface Suite™ for Microsoft® Windows v 4.10. US EPA, United States Environmental Protection Agency, Washington, DC, USA.

KOCWIN v2.00


SMILES used as identifier

The following journal article explains the MCI prediction methodology and its use:
(1) Meylan, W., P.H. Howard and R.S. Boethling, "Molecular Topology/Fragment Contribution Method for Predicting Soil Sorption Coefficients", Environ. Sci. Technol. 26: 1560-7 (1992).


Currently there is no universally accepted definition of model domain.  However, users may wish to consider the possibility that log Koc estimates are less accurate for compounds outside the MW range of the training set compounds, and/or that have more instances of a given fragment than the maximum for all training set compounds.  It is also possible that a compound may have a functional group(s) or other structural features not represented in the training set, and for which no fragment coefficient or correction factor was developed.  These points should be taken into consideration when interpreting model results.
The minimum and maximum values for molecular weight are the following:

 
Training Set Molecular Weights:

Minimum MW:  32.04

Maximum MW:  665.02

Average MW:  224.4

 
Validation Molecular Weights:

Minimum MW:  73.14

Maximum MW:  504.12

Average MW:  277.8

 

Principles of method if other than guideline:

KOCWIN (v2.00): estimation using log Kow

GLP compliance:

no

Type of method:

other: QSAR estimation: KOCWIN v2.00: Koc estimate from log Kow

Media:

soil

Test temperature:

25 °C

Type:

Koc

Remarks:

Estimate from Log Kow

Value:

103.1 L/kg

Temp.:

25 °C

Type:

log Koc

Remarks:

Estimate from Log Kow

Value:

2.013 L/kg

Temp.:

25 °C

Type:

Koc

Remarks:

Estimate from MCI

Value:

446 L/kg

Temp.:

25 °C

Type:

log Koc

Remarks:

Estimate from MCI

Value:

2.649 L/kg

Temp.:

25 °C

Koc Estimate from MCI:
First Order Molecular Connectivity Index	7.237
Non-Corrected Log Koc (0.5231 MCI + 0.60)	4.3725
Fragment Correction(s)
2   Nitrogen-to-Cycloalkane (aliphatic)	-1.7232
Corrected Log Koc	2.6493
Estimated Koc:	446.1 L/kg

Koc Estimate from Log Kow:
Log Kow  (calculated)	3.26
Non-Corrected Log Koc (0.55313 logKow + 0.9251)	2.7283
Fragment Correction(s)
2   Nitrogen-to-Cycloalkane (aliphatic)	-0.7151
Corrected Log Koc	2.0132
Estimated Koc:	103.1 L/kg

Description of key information

Adsorption to solid soil phase expected.

Additional information

The Koc value for PACM (4,4'-methylenebis(cyclohexylamine)) was estimated by the Molecular Connectivity Index (MCI) module and the log KOW module. The MCI method is the more reliable of the two calculation methods in the KOCWIN v2.00 model. The molecular weight of PACM (molecular weight = 210.37 g/mol) falls within the molecular weight range of both the training data set (MW range 32.04 g/mol to 665.02 g/mol) and the validation data set (73.14 g/mol to 504.12 g/mol). The correction factor for the nitrogen-to-cycloalkane (aliphatic) structure (-0.861602) was applied twice (-1.7232) to the calculation of the log Koc by the MCI methodology. The MCI method resulted in a Koc of 446 (log Koc = 2.65), while the log KOW method gave a slightly lower Koc of 103 (log Koc = 2.01). Both calculated values refer to the uncharged molecule. However at environmentally relevant conditions (pH 5 to 8), PACM will be present in ionised form (pKa2 = 11.1 at 20 °C; Baltussen, 2010).

Therefore, the Koc was also calculated for the environmentally relevant pH range according to Franco and Trapp (2008, 2009, 2010). This resulted in a log Koc of 4.25 at pH 5 to 8 (Koc = 17958 at pH 5 to Koc = 17781 at pH 8).