Triphenylformazan

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Structural formula
Structural formula of triphenylformazan
General
Surname Triphenylformazan
other names
  • 1,3,5-triphenylformazan
  • ( NE , E ) - N ′ - (Phenylamino) - N - (phenylimino) benzene carboximidamide
Molecular formula C 19 H 16 N 4
Brief description

dark brown powder

External identifiers / databases
CAS number 531-52-2
EC number 208-509-1
ECHA InfoCard 100.007.737
PubChem 5463277
Wikidata Q60983436
properties
Molar mass 300.36 g mol −1
Physical state

firmly

Melting point

163-166 ° C

safety instructions
GHS labeling of hazardous substances
07 - Warning 09 - Dangerous for the environment

Caution

H and P phrases H: 302-400
P: 273
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Triphenylformazan is an organic chemical compound belonging to the formazane class. The formazans are derivatives of the hypothetical parent compound NH = N ‑ CH = N ‑ NH 2 - formally a hydrazone substituted with an azo group . These were first described in 1892 by Hans von Pechmann and Eugen Bamberger . Triphenylformazan is colored red and belongs to the formazan dyes .

Manufacturing

Triphenylformazane ( 6 ) is obtained by the coupling of benzenediazonium chloride ( 5 ) prepared by diazotization of aniline ( 4 ), the hydrazone ( 3 ) of benzaldehyde ( 1 ) and phenylhydrazine ( 2 ). The H atom of the aldehyde group is substituted by the diazonium radical.

Synthesis of triphenylformazan
Synthesis of triphenylformazan

Reactions

Triphenylformazan can be reversibly oxidized , for example with lead tetraacetate or N- bromo succinimide , to triphenyltetrazolium chloride . By reduction, e.g. B. with ammonium sulfide , you get the formazan again.

Redox reaction between triphenylformazan and triphenyltetrazolium chloride
Redox reaction between triphenylformazan and triphenyltetrazolium chloride

As a bidentate ligand, triphenylformazan forms chelate complexes with copper , nickel and cobalt . By introducing hydroxyl or carboxyl groups into the phenyl radicals in the 1- and 5-positions, tridentate and tetradentate metal formazan complexes are accessible.

Formazan metal complexes
two-, three- and tetradentate formazan metal complexes

use

The red triphenylformazan is formed in the TTC test when the colorless triphenyltetrazolium chloride is reduced by various dehydrogenases . This color change, known as vital color, is an indication of the metabolic activity of cells in cell biology .

Tetradentate copper complexes of various triphenylformazan derivatives play an important role as blue reactive dyes in textile dyeing.

literature

  • Jewad Shneine: Chemistry Of Formazan. In: International Journal of Research in Pharmacy and Chemistry. January 2015, pp. 41–76 .;

Individual evidence

  1. a b c d data sheet 1,3,5-triphenyltetrazolium-formazan from Sigma-Aldrich , accessed on January 15, 2019 ( PDF ).
  2. ^ A b R. Price: The Chemistry of Metal Complex Dyestuffs . In: K. Venkataraman (Ed.): The Chemistry of Synthetic Dyes . tape III . Academic Press, New York, London 1970, ISBN 0-12-717003-0 , pp. 373 ff .
  3. H. v. Pechmann: About the so-called. mixed azo compounds . In: Reports of the German Chemical Society . tape 25 , no. 2 , July 1892, p. 3190 , doi : 10.1002 / cber.189202502174 .
  4. Eug. Bamberger, E. Wheelwright: About the action of diazobenzene on acetoacetic ether . In: Reports of the German Chemical Society . tape 25 , no. 2 , July 1892, p. 3201 , doi : 10.1002 / cber.189202502175 .
  5. ^ A b Hans Beyer, Wolfgang Walter: Textbook of organic chemistry . 18th edition. S. Hirzel Verlag, Stuttgart 1978, ISBN 3-7776-0342-2 , p. 667 .
  6. FP Altman: tetrazolium salts and formazan. In: Prog. Histochem. Cytochem. Vol. 9 (1976), pp. 1-56, PMID 792958 .