Application of ammonium cerium nitrate
Information sources：本站 | Release date：
| Browse volume：522
1. For the determination of trace silver ions. Redox titrant. Olefin polymerization catalyst.
2. Used as an analytical reagent, commonly used in the preparation of redox titration standard solutions, as a color developer for the detection of polyols by thin layer chromatography, to prepare a raw material for a phosphate-sensitive membrane electrode composition and as a potentiometric titration method Amine reagents. It can also be used as an oxidizing agent and an olefin polymerization catalyst.
3. Ammonium cerium nitrate CAN is a strong oxidant, which is more oxidizing under acidic conditions, second only to F2, XeO3, Ag2+, O3, HN3. In aqueous solutions and other protic solvents, CAN is a single-electron oxidant that can be used to determine CAN consumption from color changes (from orange to light yellow). Due to the limitations of solubility in organic solvents, the reactions involving CAN are mostly carried out in a mixed solvent such as water/acetonitrile. In the presence of other oxidizing agents such as sodium bromate, t-butyl hydroperoxide and oxygen, the recycling of Ce4+ can be achieved to achieve a catalytic reaction. In addition, CAN is an effective nitrating reagent.
CAN has an oxidizing activity for oxygen-containing compounds such as alcohols, phenols, ethers, etc., and has specific oxidizing properties for secondary alcohols. If benzyl alcohol is oxidized to the corresponding aldehyde ketone, even p-nitrobenzyl alcohol can be oxidized to p-nitrobenzyl ketone by the CAN/O2 catalytic oxidation system. Further, a cyclic ether compound can also be obtained for a specific secondary alcohol such as 4-enol or 5-enol.
For catechol, hydroquinone and their methyl ether compounds, they can be oxidized to hydrazine under the action of CAN. For example, catechol is converted to o-benzoquinone, hydroquinone is rapidly converted to p-benzoquinone by CAN and ultrasonic waves, and aryl ether is converted to p-benzoquinone.
A dicarbonyl compound can also be obtained for the oxidation reaction of the epoxy compound. In addition, CAN also has an oxidizing activity for a specific structure of a carbonyl compound, such as a reaction for oxidizing a polycyclic ketone to a lactone.
As a single electron oxidant, CAN can also achieve intermolecular or intramolecular carbon-carbon bond formation reactions. For example, the oxidative addition reaction of 1,3-dicarbonyl compound with styrene system under CAN (Equation 7) , or the dimerization reaction of aniline itself, in addition to oxidation reaction, CAN is also an effective nitrating reagent. Especially the nitration of the aromatic ring system. For example, in the acetonitrile, CAN reacts with anisole to obtain an ortho-nitration product. However, due to the strong oxidizing property of CAN, the polycyclic reaction of the aromatic ring system is often caused, and even a polymer which is difficult to separate is formed. Studies have found that the adsorption of CAN on silica gel reduces its oxidative properties, thereby reducing the formation of polynitro products. For example, in acetonitrile, silica gel is used as a carrier, and carbazole and 9-alkylcarbazole are nitrated by CAN, and the yield can be increased to 70% to 80%.