Дибензо-18-краун-6

Описание

Dibenzo-18-crown-6 (DB18C6) is the first crown ether synthesized by Pedersen in 1967 and has the strongest binding affinity to a potassium cation (K+) among alkali metal cations. With the similarity of the sizes between K+ and the cavity of crown ether, it had long been believed that the binding selectivity comes from the size relationship between the metal cation and the cavity. However, it was reported that under identical experimental conditions, K+ bound strongly to all crown ethers (12-crown-4 to 24-crown-8) irrespective of the ring size among other cations such as Na+, Ca2+, and NH4+. Moreover, in the gas phase, 18-crown-6 (18C6) and dibenzo18-crown-6 (DB18C6) form preferential complexation in the order Li+ > Na+ > K+ > Rb+ > Cs+, while in the aqueous solution both of them show highest complexion capacity for K+ rather than Li+[1-2].

Химические свойства

white to slightly beige fluffy powder

Использование

Dibenzo-18-crown-6, is used as an important raw material and intermediate used in organic Synthesis, pharmaceuticals, agrochemicals and dyestuff. It is an important organic intermediate.

Методы очистки

Crystallise it from *benzene, n-heptane or toluene and dry it under vacuum at room temperature for several days. [Szezygiel J Phys Chem 91 1252 1987, V.gtle ed. Top Corr Chem (Host Guest Complex Chemistry) 98 1981.]