He Silver dichromate , With formula Ag 2 Cr 2 OR 7, Is a ternary inorganic salt consisting of three chemical elements: silver, chromium and oxygen.
It has a solubility product constant of 2 x 10 -7 So it is insoluble in water under standard conditions of temperature and pressure. Its name uses the IUPAC nomenclature established for salts derived from oxyacid acids.
- Systematic name : Dioxide-oxide (dioxo) chromium) oxo-dioxochromo of diploma
- Formula : Ag 2 Cr 2 OR 7
- Color : Red
- Molecular mass : 431.74 g / mol
- Density : 4.77 g / cm 3
- Kps : 2 x 10 -7
Synthesis
It can be synthesized from potassium dichromate in the presence of silver nitrate according to the reaction:
Additionally it can be used for the synthesis of the corresponding chromate by heating the solid in water to 100 ° C.
Applications
Although the precursors of silver dichromate (K 2 Cr 2 OR 7 And H 2 Cr 2 OR 7 ) Are involved in many more chemical processes, silver dichromate has been used to synthesize compounds of coordination with pyridinic ligands of the type Py 4 Ag 2 Cr 2 OR 7.
These have proven to be highly effective as catalysts in the oxidation of allylic and benzyl alcohols with high conversion rates.
The synthesis of this type of compounds involves the addition of K 2 Cr 2 OR 7 , AgNO 3 And pyridine in a 1: 2: 4 stoichiometric ratio.
The use of the supported polyethylenimine on a silver dichromate surface has a high oxidizing power and can be used to prepare derivatives of various benzyl alcohols.
It has also been used to study the kinetics of the reduction of chromium (VI) ions in acetic acid solutions.
Among other applications, the Golgi preparations used for the study of brain tissue in rats using X-ray powder diffraction are highlighted.
Recently, its ability to act as a photocatalyst has been discovered using visible radiation.
However, in order to function in this way, it is necessary nano particularlo so that novel methods such as chemical sonication are used where by ultrasound it is possible to modify the crystal structure of Ag 2 Cr 2 OR 7 .
Silver dichromate has been used in certain quantitative analyzes for the determination of chlorides and bromides in organic compounds.
Mixtures of potassium and silver dichromate are used regularly in the first steps of these analyzes to be equimolar.
References
- Charchem, 2017. Retrieved from easychem.org.
- Firouzabadi, H., Sardarian, A., & Gharibi, H. (1984). Tetrakis (Pyridine) silver Dichromate Py4Ag2Cr207 - A Mild and Efficient Reagent for the Conversion of Benzylic and Allylic Alcohols to Their Corresponding Carbonyl Compounds. Synthetic Communications, 14 (1), 89-94. Retrieved from doi.org.
- Tamami, B., Hatam, M., & Mohadjer, D. (1991). Poly (vinyl pyridine) supported silver dichromates as versatile, mild and efficient oxidants for different organic compounds. Polymer, 32 (14), 2666-2670. Retrieved from doi.org.
- Goudarzian, N., Ghahramani, P., & Hossini, S. (1996). Polymeric reagent (I): Polyethyleneimine-supported silver dichromate as a novel oxidizing agent. Polymer International, 39 (1), 61-62. Retrieved from doi.org.
- Al-Sheikhly, M., & McLaughlin, W.L. (1991a). The mechanisms of the reduction reactions of Cr (VI) in the radiolysis of acidic potassium and silver dichromate solutions in the presence or absence of acetic acid. International Journal of Radiation Applications and Instrumentation. Part C. Radiation Physics and Chemistry, 38 (2), 203-211. Retrieved from doi.org.
- Fregerslev, S., Blackstad, T. W., Fredens, K., & Holm, M. J. (1971). Golgi potassium-dichromate silver-nitrate impregnation. Histochemie, 25 (1), 63-71. Retrieved from doi.org.
- Soofivand, F., Mohandes, F., & Salavati-Niasari, M. (2013). Silver chromate and silver dichromate nanostructures: Sonochemical synthesis, characterization, and photocatalytic properties. Materials Research Bulletin, 48 (6), 2084-2094. Retrieved from doi.org.
- [Links] Analytical Chemistry of Organic Halogen Compounds: International Series in Analytical Chemistry. Elsevier. 119-120.