Ioxynil

Structural formula
General
Surname	Ioxynil
other names	Ioxynil 4-hydroxy-3,5-diiodobenzonitrile 4-cyano-2,6-diiodophenol 3,5-diiodo-4-hydroxybenzonitrile
Molecular formula	C 7 H 3 I 2 NO
Brief description	colorless solid with a slightly phenolic odor
External identifiers / databases
CAS number 1689-83-4 2961-62-8 (sodium salt) 3861-47-0 (octanoate) PubChem 15530 Wikidata Q186546
properties
Molar mass	370.92 g mol −1
Physical state	firmly
density	2.72 g cm −3 1.81 g cm −3 (octanoate)
Melting point	212-213 ° C 56.6 ° C (octanoate)
solubility	practically insoluble in water (50 mg l −1 at 25 ° C) soluble in chloroform, ether, acetone, ethanol, methanol, cyclohexanone, tetrahydrofuran and dimethylformamide
safety instructions
GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary danger H and P phrases H: 301 + 331-312-319-361d-373-410 P: 201-261-273-280-301 + 310 + 330-304 + 340 + 311
Toxicological data	110 mg kg −1 ( LD 50 ,  rat ,  oral ) 190 mg kg −1 ( LD 50 ,  rat ,  oral , octanoate)
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Ioxynil is an active ingredient for crop protection and a chemical compound from the group of substituted phenols , nitriles and organic iodine compounds .

presentation

Ioxynil can be obtained by reacting 4-hydroxybenzaldehyde with iodine and then reacting with hydroxylamine and acetic anhydride or directly by reacting 4-hydroxybenzonitrile with iodine.

properties

Ioxynil is a flammable, light-sensitive, colorless solid with a slightly phenol-like odor, which is practically insoluble in water. It disintegrates under UV light. Its octanoate (4-cyano-2,6-diiodophenyl octanoate C ₁₅ H ₁₆ I ₂ NO ₂ ) is also a colorless solid that is practically insoluble in water and hydrolyzes to ioxynil under alkaline conditions. The sodium salt of ioxynil is easily soluble in water.

use

Ioxynil, like its relative bromoxynil, is used as an active ingredient in crop protection products. It was created by May & Baker Ltd. and Amchem Products Inc. and first described in the literature in 1963. It is often used in combination with other herbicides and sold under the trade names Actril, Actrilawn, Bentrol, Belgran, Certrol, Cipotril, Dantril, Iotox, Iotril, Oxytril, Sanoxynil, Totril, Toxynil and Trevespan. The effect is based among other things on the inhibition of the Hill reaction and the decoupling of oxidative phosphorylation .

Admission

Ioxynil is not approved as an active ingredient in plant protection products in the EU countries, so there are no products with this active ingredient on the market in Germany or Austria. In Switzerland, too, no pesticides containing this active ingredient are permitted.

Individual evidence

1. ↑ ^{a b c d e f g h i} Entry on ioxynil in the GESTIS substance database of the IFA , accessed on January 8, 2018(JavaScript required) .
2. ↑ ^{a b c} Entry on ioxyniloctanoate in the GESTIS substance database of the IFA , accessed on February 1, 2016(JavaScript required) .
3. ^ Entry on Ioxynil in the Hazardous Substances Data Bank , accessed July 27, 2012.
4. ↑ Entry on Ioxynil in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
5. ↑ Thomas A. Unger: Pesticide synthesis handbook . 1996, ISBN 978-0-8155-1401-5 , pp. 825 ( limited preview in Google Book search).
6. ^ ^{A b} Robert Irving Krieger: Handbook of pesticide toxicology, Volume 1 . Academic Press, 2001, ISBN 978-0-12-426260-7 , pp. 1235 .
7. ↑ Vallurupalli Sivaji Rao: Principles of weed science . Science Publishers, 1999, ISBN 978-1-57808-069-4 , pp. 178 ( limited preview in Google Book search).
8. ↑ General Directorate Health and Food Safety of the European Commission: Entry on Ioxynil in the EU pesticide database; Entry in the national registers of plant protection products in Switzerland , Austria and Germany ; accessed on December 7, 2019.