Lyotropic liquid crystalline phthalocyanines containing 4-((S)-3,7-dimethyloctyloxy)phenoxy moieties

The novel metal free phthalocyanine and its copper complex which are octa-substituted at the peripheral positions with 4-(([Formula: see text]-3,7-dimethlyoctyloxy)phenoxy moieties were synthesized and characterized by FT-IR, 1H NMR and mass spectroscopy. Their mesomorphic properties were studied by polarizing optical microscopy. The spectroscopic properties and aggregation behaviors of the novel phthalocyanines were also investigated by UV-vis spectroscopy in different solvents with same concentration as well as in a wide range of concentrations of chloroform. Both compounds with chloroform and [Formula: see text]-dodecane clearly show the lyotropic columnar mesophase in a wide temperature range whereas thermotropic liquid crystalline behavior for both compounds is not observed. Both of these novel compounds show no aggregation in toluene, tetrahydrofuran, dichloromethane and chloroform.

Liquid crystalline properties of unsymmetrically substituted phthalocyanines: structural features leading to nematic mesophase materials

A novel homologous series of four 1,4,8,11,15,18-hexakis(pentyl)-22-methyl-25-hydroxyalkylphthalocyanine derivatives with the hydroxyalkyl chain varying from hydroxynonyl through to hydroxydodecyl has been synthesized to investigate the role of the hydroxyalkyl chain in promoting thermotropic liquid crystalline behavior. Polarizing optical miscoscopy reveals that the compound with the shortest hydroxyalkyl chain (hydroxynonyl) exhibits a mesophase with a texture characteristic of a columnar mesophase, common among liquid crystalline phthalocyanine derivatives. However, as the chain is lengthened along the series, there appears a second type of mesophase that shows a schlieren texture. Such a texture is characteristic of a nematic phase and rare among liquid crystalline phthalocyanine derivatives. A fifth compound, the novel 1,4,8,11,15,18-hexakis(pentyl)-22-methyl-25-dodecylphthalocyanine, exhibits only columnar mesophase behavior suggesting that the hydroxyl group at the end of the longer chains of the former compounds is important in developing the nematic phase.

New Arylidene—Siloxane Polyesters

New siloxane-containing polyesters with arylidene mesogenic moieties were prepared by copolycondensation reactions between bis(hydroxybuthyl)siloxanes, 2,6-bis(4-hydroxybenzylidene)cyclohexanone, and diacid chlorides such as sebacoyl and terephthaloyl. The polymer structure was confirmed by IR and 1H-NMR spectroscopy. They were characterized by gel permeation chromatography and ultraviolet analyses. The thermotropic liquid crystalline behavior was investigated by differential scanning calorimetry and polarized optical microscopy.