(4-tert-butyl-2,6-dimethylphenyl)acetonitrile

Henry's Law constant

Administrative data

Endpoint:

Henry's law constant

Type of information:

(Q)SAR

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Accepted calculation method, substance not fully within applicability domain

Justification for type of information:

QSAR prediction: migrated from IUCLID 5.6

Data source

Reference

Reference 1

Reference Type:

other: EPIWin calculation

Title:

Unnamed

Year:

2014

Report date:

2014

Reference 2

Reference Type:

other: Estimation software

Title:

Estimation Programs Interface Suite for Microsoft Windows, v4.11

Author:

US EPA

Year:

2012

Bibliographic source:

United States Environmental Protection Agency, Washington, DC, USA

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Calculation using HENRYWIN (v3.20) Bond Method

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

(4-tert-butyl-2,6-dimethylphenyl)acetonitrile

EC Number:

284-183-4

EC Name:

(4-tert-butyl-2,6-dimethylphenyl)acetonitrile

Cas Number:

84803-57-6

Molecular formula:

C14H19N

IUPAC Name:

2-(4-tert-butyl-2,6-dimethylphenyl)acetonitrile

Constituent 2

Reference substance name:

Cc1cc(C(C)(C)C)cc(C)c1CC(#N)

IUPAC Name:

Cc1cc(C(C)(C)C)cc(C)c1CC(#N)

Details on test material:

- Name of test material: Benzeneacetonitrile, 4-(1,1-dimethylethyl)-2,6-dimethyl-

Results and discussion

Henry's Law constant H

H:

0.786 Pa m³/mol

Temp.:

25 °C

Any other information on results incl. tables

Result table for Bond Contribution Method from HENRYWIN v3.20

CLASS	BOND CONTRIBUTION DESCRIPTION	COMMENT	VALUE
Hydrogen	17 Hydrogen to Carbon (aliphatic) Bonds		-2.0345
Hydrogen	2 Hydrogen to Carbon (aromatic) Bonds		-0.3086
Fragment	3 C-C		0.3489
Fragment	4 C-Car		0.6477
Fragment	1 C-CN		3.2624
Fragment	6 Car-Car		1.5828
Result	Bond Estimation Method for LWAPC Value	Total	3.499
Henrys law constant at 25°c			7.76 E-06 atm·m³/mole
			3.17 E-04 unitless
			7.87 E-01 Pa·m³/mole

Applicant's summary and conclusion

Executive summary:

QPRF: HENRYWIN v3.20: Bond contribution method

1.	Substance	2,6-Dimethyl-4-tert.-butylbenzylcyanid
2.	General information
2.1	Date of QPRF	See “Data Source (Reference)”
2.2	QPRF author and contact details	See “Data Source (Reference)”
3.	Prediction
3.1	Endpoint (OECD Principle 1)	Endpoint	Degree of volatilisation of substances from the aquatic environment
		Dependent variable	Henry’s Law Constant
3.2	Algorithm (OECD Principle 2)	Model or submodel name	HENRYWIN: Bond contribution method
		Model version	v. 3.20
		Reference to QMRF	Henry’s Law constant (HLC) using HENRYWIN v3.2: Estimation Accuracy (QMRF)
		Predicted value (model result)	See “Results and discussion: Henry’s Law constant H”
		Input for prediction	Chemical structure via CAS number or SMILES
		Descriptor values	- Bond contribution values - Correction factors
3.3	Applicability domain (OECD principle 3)	Domains:
		1) Molecular weight (range of test data set: 26.04 to 451.47 g/mol, mean: 144.64 g/mol) (On-Line HENRYWIN User’s Guide, Ch. 7.4 Estimation Domain and Appendix G)	Substance within range (201.31 g/mol)
		2) Maximum number of instances of bond in any of the training set compounds (On-Line HENRYWIN User’s Guide, Appendix D)	Exceeded
		3) Maximum number of instances of correction factor in any of the training set compounds (On-Line HENRYWIN User’s Guide, Appendix E)	Not exceeded
3.4	The uncertainty of the prediction (OECD principle 4)	According to REACH Guidance Document R.7a, Appendix R.7.1-1 (Nov. 2012), measurement of HLC is not highly accurate, especially for very high or very low HLC values. The bond contribution method regarded by Altschuh et al. (1999) to produce the most reliable results with the exception of organochlorine pesticides. However, for some compounds, the method can yield a Henry's Law constant of 1.0x10^-12atm*m^3/mol or smaller. Numbers which are smaller than this value may be unrealistically low.
3.5	The chemical mechanisms according to the model underpinning the predicted result (OECD principle 5)	The compound is split into a summation of individual bonds which comprise the compound. The summation of these bonds (= bond contribution values) is set equal to LWPAC. Correction factors were developed to correct for polar interactions and other deviations from the regression curve, which are applied to members of some chemical classes.

References:

Altschuh, J.R., Bruggemann, H. Santl, G. Eichinger, and O.G. Piringer.1999. Henry’s law constants for a diverse set of organic chemicals: experimental determination and comparison of estimation methods. Chemosphere 39: 1871-87.

.

Identified number of bonds and correction factors for the current substance:

HLC Appendix D, Table D-1: Bond Contribution Values Derived by Least-Square Regression Analysis

Bond	Coefficient Value	No. Compounds  in Training Set containing the Bond	Maximum No. of instances of each Bond occurring in any single compound	Comment	No. of instances of each bond found for the current substance
C-H	-0,119677	284	27	Hydrogen bond	17
Car-H	-0,154294	93	12	Hydrogen bond	2
C-C	0,116304	200	9		3
C-Car	0,161929	47	3		4
C-CN	3,262422	3	1		1
Car-Car	0,263807	94	21	intra-ring type	6

HLC Appendix D, Table D-2: Bond Contribution Values from a Subsequent Regression

Not applicable

 

HLC Appendix D, Table D-3: Additional Bond Contribution Values Used HENRYWIN

Not applicable

 

HLC Appendix E, Table E-1: Bond Correction Factors Derived from the Original Regression

Not applicable

 

HLC Appendix E, Table E-2: Bond Correction Factors Derived from the Second Regression

Not applicable

 

HLC Appendix E, Table E-3: Bond Correction Factors Derived Individually

Not applicable