The reaction rate of a catalyzed reaction is faster than the reaction rate of the uncatalyzed reaction at the same temperature.14098-44-3, Name is Benzo-15-crown-5, molecular formula is C14H20O5. In a Article£¬once mentioned of 14098-44-3, Recommanded Product: Benzo-15-crown-5
Columnar and smectic liquid crystals based on crown ethers
Unsymmetrical benzo[15]-crown-5 ethers 5 with one lateral ortho-terphenyl unit bearing alkoxy side chains of varying chain lengths (C5-C14) were prepared from 3,4-dialkoxyphenylbromides 2. Complexation with metal salts MX (M = Na, Cs) afforded the corresponding derivatives MX¡¤5. The uncomplexed crown ethers 5h and 5i, with dodecyloxy and tetradecyloxy side chains, respectively, exhibit liquid crystalline properties. In the series of complexed crown ethers, liquid crystal properties appeared as early as NaI¡¤5f with C 9H19 side chains. Whereas the uncomplexed 5h,i form smectic mesophases, the complexed NaI¡¤5g and NaI¡¤5h exhibit textures typical of columnar mesophases. These results were supported by X-ray diffraction measurements (WAXS, SAXS), which revealed smectic (5h,i), rectangular columnar (NaI¡¤5g), and hexagonal columnar (NaI¡¤5h) mesophases. As the liquid crystalline phase might retain packing features of the solid-state structure, single-crystal X-ray analyses were also performed for some of the uncomplexed and complexed crown ether derivatives. The complex NaI3¡¤5a displays a sandwich-type structure, with the crown ether cores mutually antiperiplanar and maintaining an almost perfect crown conformation. In contrast, non-mesogenic uncomplexed crown ether 5b displays a layer-type ordering in the solid phase.
Note that a catalyst decreases the activation energy for both the forward and the reverse reactions and hence accelerates both the forward and the reverse reactions.Recommanded Product: Benzo-15-crown-5, you can also check out more blogs about14098-44-3
Reference£º
Chiral Catalysts,
Chiral catalysts – SlideShare