Reinecke salt
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| Reinecke salt | |
|---|---|
 |
|
| General | |
| Systematic name | Chromate(1-), diaminetetrakis- (thiocyanato-N)-, ammonium, (OC-6-11)- |
| Other names | ammonium tetrathiocyanato- diamminechromate(III), Reinecke salt, |
| Molecular formula | NH4[Cr(SCN)4(NH3)2] |
| Molar mass | 354.42 g/mol |
| Appearance | dark red solid |
| CAS number | [13573-16-5] |
| Properties | |
| Density and phase | ? g/cm3, ? |
| Solubility in water | soluble in hot water |
| Solubility in other solvents | soluble in ethanol |
| Melting point | 270 °C |
| Boiling point | decomposes |
| Acidity (pKa) | ? |
| Structure | |
| Coordination geometry |
octahedral |
| Crystal structure | ? |
| Dipole moment | 0 D |
| Hazards | |
| MSDS | External MSDS |
| Main hazards | toxic |
| NFPA 704 | |
| R/S statement | R: 20/21/22 S: 36 |
| RTECS number | na |
| Supplementary data page | |
| Thermodynamic data |
Phase behaviour Solid |
| Spectral data | UV, IR, NMR, MS |
| Related compounds | |
| Related compounds | [Co(NH3)6]Cl3, KSCN, Chromium(III) chloride |
| Except where noted otherwise, data are given for materials in their standard state (at 25°C, 100 kPa) Infobox disclaimer and references |
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Reinecke's salt is a chemical compound with the formula NH4[Cr(SCN)4(NH3)2]. It consists of dark-red crystals, soluble in boiling water and ethanol.
Chromium is here in the 3+ oxidation state, surrounded by six ligands in an octahedral geometry; the NH3 ligands are mutually trans. It was first reported in 1963.[1]
According to Organic Syntheses, NH4[Cr(SCN)4(NH3)2] is prepared by treatment of molten NH4SCN (ca. 145–150 °C) with (NH4)2Cr2O7.[2]
This salt was once widely used to precipitate primary and secondary amines as their ammonium salts. Included in the amines that effectively form insoluble precipitates are those derived from the amino acids, including proline and hydroxyproline. It is also a reacting agent on Hg2+-compounds, giving a red color or a red precipitate.
[edit] References
- ^ Reinecke, Annalen, volume 126, pages 113ff (1863).
- ^ Dakin, H. D. Organic Syntheses, Coll. Vol. 2, p.555 (1943); Vol. 15, p.74 (1935).
