Kupferron

Structural formula
General
Surname	Kupferron
other names	Ammonium 2-oxo-1-phenylhydrazinolate ( IUPAC ) N -nitroso- N -phenylhydroxylamine, ammonium salt Cupferron
Molecular formula	C 6 H 9 N 3 O 2
Brief description	light yellow, crystalline solid
External identifiers / databases
CAS number 135-20-6 EC number 205-183-2 ECHA InfoCard 100.004.713 PubChem 2724103 ChemSpider 2006262 Wikidata Q3007584
properties
Molar mass	155.15 g mol −1
Physical state	firmly
Melting point	150-155 ° C
solubility	soluble in water (<1 g l −1 at 18.5 ° C)
safety instructions
GHS labeling of hazardous substances danger H and P phrases H: 301-315-319-335-351 P: 261-281-301 + 310-305 + 351 + 338
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Kupferron is the ammonium salt of N -nitroso- N -phenylhydroxylamine , which is used as a reagent for the complexation of metal ions. The anion , as a bidentate ligand, binds the metal ions in a five-membered ring via the two oxygen atoms . The compound was introduced in 1909 by Oskar Baudisch in the quantitative analysis of copper and iron ions.

Extraction and presentation

Kupferron is produced from phenylhydroxylamine in a multi-stage reaction . This is first converted into the ammonium salt with ammonia and then reacted with amyl nitrite :

${\displaystyle \mathrm {C_{5}H_{5}NHOH+\ NH_{3}\ {\xrightarrow[{}]{}}\ NH_{4}[(C_{6}H_{5})NHO]} }$

${\displaystyle \mathrm {NH_{4}[(C_{6}H_{5})NHO]+\ C_{4}H_{3}ONO\ {\xrightarrow[{}]{}}\ NH_{4}[(C_{6}H_{5})N(NO)O]+C_{4}H_{3}OH} }$

use

Kupferron is used to precipitate metal ions such as copper , iron , titanium , vanadium , thorium , cerium , cobalt , aluminum , zinc or tin . The metal copper ronates formed are sparingly soluble in water, but easily soluble in organic solvents. It is therefore used to separate unwanted elements prior to quantitative determination.

Individual evidence

1. ↑ ^{a b} Cupferron data sheet at Sigma-Aldrich , accessed on March 22, 2015 ( PDF ).
2. ↑ entry to cupferron at ChemicalBook , accessed March 22, 2015.
3. ↑ ^{a b} Entry on Kupferron in the GESTIS material database of the IFA , accessed on July 23, 2016(JavaScript required) .
4. ↑ K. Schröder: The use of the cupferron in quantitative analysis . In: Journal for Analytical Chemistry . tape 61 , no. 1-2 , January 1922, pp. 60-66 , doi : 10.1007 / bf02425240 ( PDF ).
5. ^ KH Slotta, KR Jacobi: Production of organic reagents in the analytical laboratory. II. "Kupferron" (ammonium salt of nitrosophenylhydroxylamine) . In: Journal for Analytical Chemistry . tape 80 , no. 3-4 , March 1930, pp. 97-103 , doi : 10.1007 / BF01365065 ( PDF ).
6. ↑ entry to cupferron in the Report on Carcinogens, Thirteenth Edition .
7. ↑ Othmar G. Koch, Gertrud A. Koch-Dedic: Handbook of trace analysis: The enrichment and determination of trace elements using chemical, physical and microbiological methods . Springer, 1964, ISBN 978-3-642-65423-7 , pp. 255 ff.

literature

• CS Marvel: Cupferron In: Organic Syntheses . 4, 1925, p. 19, doi : 10.15227 / orgsyn.004.0019 ; Coll. Vol. 1, 1941, p. 1 ( PDF ).
• D. van der Helm, Lynne L. Merritt jr., Robert Degeilh, Caroline H. MacGillavry: The crystal structure of iron cupferron Fe (O ₂ N ₂ C ₆ H ₅ ) ₃ , In: Acta Cryst , 1965, 18, p 355-362; doi : 10.1107 / S0365110X65000816 ( PDF ).