Phenylhydrazine
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| General | ||||||||||||||||
| Surname | Phenylhydrazine | |||||||||||||||
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| Molecular formula | C 6 H 8 N 2 | |||||||||||||||
| Brief description |
red-brown liquid with an aromatic odor |
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| properties | ||||||||||||||||
| Molar mass | 108.14 g mol −1 | |||||||||||||||
| Physical state |
liquid |
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| density |
1.1 g cm −3 |
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| Melting point |
19.6 ° C (24 ° C for the hemihydrate) |
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| boiling point |
244 ° C (partial decomposition) |
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| Vapor pressure |
6 Pa at 20 ° C |
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| solubility |
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| safety instructions | ||||||||||||||||
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| MAK |
Switzerland: 5 ml m −3 or 22 mg m −3 |
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| As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . | ||||||||||||||||
Phenylhydrazine is a chemical compound from the group of aromatic hydrazines. It is a yellowish liquid that turns increasingly dark red to red-brown in air.
history
Phenylhydrazine was the first aromatic hydrazine compound to be investigated by Emil Fischer in 1875. He produced it by reducing phenyl diazonium salts with sulfite salts . Fischer used phenylhydrazine to study the structure of carbohydrates by forming hydrazones from the aldehyde group of sugars.
Occurrence
Phenylhydrazine occurs naturally in some plants ( bay tree , legumes ).
Extraction and presentation
Phenylhydrazine is obtained commercially by diazotization of aniline followed by reduction , for the diazonium cation. B. obtained by sodium sulfite . In 1998 the production volume in Western Europe was 6650 tons.
properties
Phenylhydrazine forms monoclinic crystals and melts to an oily liquid at room temperature. It decomposes at temperatures above 260 ° C. The heat of decomposition determined by DSC is −71 kJ · mol −1 or −662 kJ · kg −1 . Its vapors are four times as heavy as air. It is a strong reducing agent and easily soluble in water.
use
Phenylhydrazine is used as an intermediate in the production of indoles , which in turn are intermediates in the synthesis of various dyes , agrochemicals and pharmaceuticals. It also serves as a raw material for the production of developers for photo technology.
It can also serve as a reagent for the detection or identification of compounds with carbonyl groups (formation of phenylhydrazones or osazones ). The use of phenylhydrazine as a laboratory chemical (analytical reagent for aldehydes , ketones and sugars through the formation of the well-crystallizing phenylhydrazones or osazones , for the detection of molybdenum and other metals) is associated with derivatization .
safety instructions
Phenylhydrazine is spontaneously flammable if it is contaminated or comes into contact with materials with a large surface (e.g. cleaning wool or sand). Its vapors can form an explosive mixture with air when heated above its flash point (89 ° C). Phenylhydrazine is considered to be carcinogenic , is a strong blood poison ( formation of methaemoglobin ) and causes eczema on the skin. In addition, it leads to irreversible damage to the blood pigment and the erythrocytes .
Compounds and derivatives of phenylhydrazine
- 1-Acetyl-2-phenylhydrazine is a derivative of both acetic acid and phenylhydrazine
- Phenicarbazide
- Phenylhydrazine · hydrochloride C 6 H 8 N 2 · HCl
- Phenylhydrazine sulfate
- 2,4-dinitro-phenylhydrazine
- 2,4-Dinitro-Phenylhydrazones derivatives for the chemical detection of carbonyl groups in aldehydes and ketones
Web links
Individual evidence
- ↑ a b c d e f g h i j Entry on phenylhydrazine in the GESTIS substance database of the IFA , accessed on February 1, 2016(JavaScript required) .
- ^ A b c Concise International Chemical Assessment Document (CICAD) for Phenylhydrazine , accessed on November 18, 2014.
- ↑ Entry on phenylhydrazine 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 .
- ↑ Swiss Accident Insurance Fund (Suva): Limit values - current MAK and BAT values (search for 100-63-0 or phenylhydrazine ), accessed on November 2, 2015.
- ↑ E. Fischer: About aromatic hydrazine compounds. In: Ber. German Chem. Ges. Volume 8, 1875, pp. 589-594.
- ↑ a b Federal Agency for Occupational Safety and Health: Datasheet Phenylhydrazine , accessed on March 31, 2013.
- ^ GH Coleman: Phenylhydrazine In: Organic Syntheses . 2, 1922, p. 71, doi : 10.15227 / orgsyn.002.0071 ; Coll. Vol. 1, 1941, p. 442 ( PDF ).
- ↑ T. Grewer, O. Klais: Exothermic decomposition - investigations of the characteristic material properties. (= Humanization of working life. Volume 84). VDI-Verlag, Düsseldorf 1988, ISBN 3-18-400855-X , p. 9.
- ↑ Report on Emil Fischer ( Memento of the original from November 12, 2007 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ Reactions of bio-organic compounds (PDF; 605 kB).
- ^ Siegfried Hauptmann : Organic chemistry. 2nd Edition. VEB Deutscher Verlag für Grundstofftindustrie, Leipzig 1985, ISBN 3-342-00280-8 , p. 522.
- ↑ External identifiers or database links to phenylhydrazinium chloride: CAS number: 59-88-1, EC number: 200-444-7, ECHA InfoCard: 100.000.404 , GESTIS substance database : 490069 , PubChem : 60962 , ChemSpider : 54924 , Wikidata : Q90571131 .
- ↑ External identifiers or database links for phenylhydrazine sulfate : CAS number: 52033-74-6, EC number: 257-622-2, ECHA InfoCard: 100.052.367 , GESTIS substance database : 144330 , PubChem : 6452561 , ChemSpider : 4954989 , Wikidata : Q72501950 .
