Ferrocyphene

Structural formula
General
Surname	Ferrocyphene
other names	Dicyanobis (1,10-phenanthroline) iron (II); Bis (o-phenantroline) iron (II) cyanide; Bis (cyano-C) bis (1,10-phenantroline-N1, N10) iron;
Molecular formula	C 26 H 16 FeN 6
Brief description	Dark purple, almost black crystals
External identifiers / databases
ECHA InfoCard	100.035.288
Wikidata	Q1407959
properties
Molar mass	504.33 g mol −1 (dihydrate); 522.34 g mol −1 (trihydrate);
Physical state	firmly
safety instructions
GHS labeling of hazardous substances danger
H and P phrases	H: 301
	P: ?
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

In Ferrocyphen is complex -bound iron (II), which two (1.10) - phenanthroline ligands and two cyanide ion is coordinated. This forms an electrically neutral chelate complex .

Ferrocyphene serves as a redox indicator in redox titrations (e.g. nitritometry ) , as the color of the complex changes from yellow (Fe ²⁺ , ferrocyphene) to purple (Fe ³⁺ , ferricyphene) through oxidation .

It is also used in the titration of weak bases in non-aqueous media and for aromatic diazotization titrations.

presentation

The best representation in the laboratory is the displacement of 1,10-phenanthroline ligands (phen) from the tris (1,10-phenanthroline) iron (II) cation by cyanide ions.

${\ displaystyle {\ ce {Fe (NH4) 2 (SO4) 2 * 6 H2O + 3 (phen * H2O)}}}$

{\ displaystyle {\ ce {-> [Fe (phen) 3SO4] + (NH4) 2SO4 + 9 H2O}}}

${\ displaystyle {\ ce {[Fe (phen) 3] SO4 + 2 KCN + 3 H2O}}}$

->

{\ displaystyle {\ ce {[Fe (phen) 2 (CN) 2] * 2 H2O + K2SO4 + (phen * H2O)}}}

Other ways, such as the displacement of cyanide ions by phenanthroline, are significantly slower and in lower yield. The direct combination of an iron (II) solution with equimolar amounts of potassium cyanide and 1,10-phenanthroline initially provides a mix of different complexes whose rearrangement to the desired product takes too long to be practical.

Individual evidence

↑ ^a ^b ^c Alfred A. Schilt: Dicyanobis (1,10-phenanthroline) iron (II) and Dicyanobis (2,2'-bipyridine) iron (II) . In: Robert W. Parry (Ed.): Inorganic Syntheses . tape 12 . McGraw-Hill, Inc., 1970, ISBN 07-048517-8 ( defective ) , p. 247 ff . (English).
↑ Template: CL Inventory / not harmonized There is not yet a harmonized classification for this substance . A labeling of bis (cyano-C) bis (1,10-phenanthroline-N1, N10) iron in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on November 14, 2016, is reproduced from a self-classification by the distributor .
↑ P. Patnaik: Dean's analytical chemistry handbook , Irwin / McGraw Hill, 2nd edition, 2004, p. 4.71. ISBN 0-07-141060-0 .
^ Alfred A. Schilt: Mixed ligand complexes of iron (ii) as nonaqueous acid-base and aqueous oxidation-reduction indicators . In: Analytica Chimica Acta . tape 26 , p. 134-143 , doi : 10.1016 / s0003-2670 (00) 88359-2 .
↑ AA Schilt, JW Sutherland: A Reversible Internal Indicator for Sodium Nitrate Titrations. In: Analytical Chemistry . tape 36 , no. 9 , May 1, 2002, pp. 1805-1807 , doi : 10.1021 / ac60215a032 .

[IS12-1] Alfred A. Schilt: Dicyanobis (1,10-phenanthroline) iron (II) and Dicyanobis (2,2'-bipyridine) iron (II) . In: Robert W. Parry (Ed.): Inorganic Syntheses . tape 12 . McGraw-Hill, Inc., 1970, ISBN 07-048517-8 ( defective ) , p. 247 ff . (English).

[2] Template: CL Inventory / not harmonized There is not yet a harmonized classification for this substance . A labeling of bis (cyano-C) bis (1,10-phenanthroline-N1, N10) iron in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on November 14, 2016, is reproduced from a self-classification by the distributor .

[3] P. Patnaik: Dean's analytical chemistry handbook , Irwin / McGraw Hill, 2nd edition, 2004, p. 4.71. ISBN 0-07-141060-0 .

[4] Alfred A. Schilt: Mixed ligand complexes of iron (ii) as nonaqueous acid-base and aqueous oxidation-reduction indicators . In: Analytica Chimica Acta . tape 26 , p. 134-143 , doi : 10.1016 / s0003-2670 (00) 88359-2 .

[5] AA Schilt, JW Sutherland: A Reversible Internal Indicator for Sodium Nitrate Titrations. In: Analytical Chemistry . tape 36 , no. 9 , May 1, 2002, pp. 1805-1807 , doi : 10.1021 / ac60215a032 .

Ferrocyphene

presentation

See also

Individual evidence