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The hole mobility of a discotic liquid-crystalline triphenylene compound is enhanced by the gelation with hydrogen-bonded fibrous aggregates.

The first dendritic crown ether polymers ('crowned' arborols: G1, G 2 and G3) have been synthesized and characterized. The convergent synthetic method was found to be more convenient than the divergent synthetic method. The building block in the branch was prepared from Nbenzyloxycarbonyl-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane and 3,5-bis(ethoxycarbonylmethoxy)benzoyl chloride. Since the basic repeating unit is the amino dicarboxylic acid, one can utilize the methods developed for peptide synthesis. Final products were obtained in moderate yields b y coupling of each generational fragment with a core (benzene-l,3,5-tricarbonyl trichloride) followed b y reduction of all amide linkages to tertiary amine linkages b y borane-dimethyl sulfide. The complexation ability of these 'crowned' arborols was estimated by two-phase solvent extraction of alkali picrate salts. We found that some of these arborols can solubilize proteins in organic solvents.

holding ratio of TFT (thin film transistor) LC mixtures. For this reason and because of their low birefringence and favorable mesogenic properties, these new substances are quite attractive as a polar component of liquid-crystal mixtures for active matrix displays with shorter switching times and lower power consumption. [12] T NI,extr , De, Dn, and g 1 were determined by linear extrapolation from a 10 wt.-% solution in the commercially available Merck mixture ZLI-4792 (T NI = 92.8 C, e = 5.27, Dn = 0.0964) as a standard host. For the pure substances the mesophases were identified by optical microscopy, and the phase transition temperatures by differential scanning calorimetry (DSC).

Crowned' arborols are synthesized for the first time using a convergent method.The novel class of cascade molecules, arborols, have recently been of much synthetic interest. [1][2][3][4][5][6][7][8][9] have also reported a similar class of cascade molecules 'starburstdendritic' polymers.In order to increase the variety of functional groups that have been used in dendritic structures we have attempted to introduce crown ethers into arborols in the hope of producing novel properties. We expected that crown ethers would act as 'nests' in arborols and metal ions would 'perch on them like birds'. As a result, the metal binding event would induce some changes in the physical properties, We address here the first successful approach to the synthesis of 'crowned' arborols.There are two different strategies for the synthesis of