15-Crown-5 [ 33100-27-5 ]

Purity: 98% | colorless ropy fluid and the boiling point ℃ (115-116 240Pa), 93-96 ℃ (18.3 Pa), 78 6.67 ℃ (Pa), relative density 1.113 (20/4 ℃), the refractive indexes, 1.4615. 18 - Grown - 6,1,4,7,10,13,16 - Hexaoxacy - clooctadecane, white crystalline. Melting point 38 - pooled ℃, boiling point ℃ (116 26.6 Pa). Crown ethers and respond ring ether, containing more than one oxygen atom is the big ring compounds. Naming the ring, the total number of atoms contained in "crown" word tagging, before oilsand oxygen atom number is marked in name after. This is dupont Pedersen in 1967 accidentally discovered and find the class of compounds has many characteristics of abnormal. | crown ether the main characteristics, is one of the metal salt, ammonium salt, organic cation compounds formed stable complex. Use of this nature, can be in various salts soluble in organic solvents. Crown ether can be cationic chela rings, and at the same time because have exterior organic gene can generate complex, can dissolve in nonpolar organic solvents. At this moment, is not solvent relaxation anion to bare anionic forms exist in solvents, so activity is great. Crown ether can make the alkali metal and organic compounds dissolved in alkali metal organic solvents. Thus in organic synthesis, optical resolution, heavy metal chelating, separation, analysis and physiological activity of medicine, biological chemistry find wide application. For example, used as phase transfer catalysts, leaving many in traditional conditions difficult to reaction, even not occur reaction, can smoothly, this kind of reaction velocity, conditions is simple, the operation is convenient, high yield. For example, benzoin in aqueous solution of condensation reaction production rate is extremely low, if in the aqueous solution to join 7% crown ethers, then can get yield is 78% of benzoin. The reaction still can be in benzene (or acetonitrile), although QingHuaJia insoluble in benzene, but if you join the 18 - champions - 6, they will not only happen reaction, and the yield can is as high as 95%. 18 - champions - 6 toxicity: rat oral lethal dose for 300mg/kg. For the eyes, skin irritant.