A comparative study of the liquid‐crystalline behavior of three homologous series of 1,2‐propanediol derivatives

Abstract

Abstract. Homologous series (R = n-hexyl to n-tetradecyl) of 3-(alky1amino)-, 3-(a1kylthio)-and 3-alkoxy-1,2-propanediols have been synthesized and their thermal behavior studied by thermomicroscopy and differential-scanning calorimetry. The occurrence of liquid-crystalline behavior was found to be strongly dependent on both the alkyl-chain length and the hetero-atom that links the alkyl chain to the 1,2-propanediol moiety. No thermotropic liquid-crystalline behavior could be observed for 3-alkoxy-1,2-propanediols; 3-(hepty1amino)-through 3-(nonylamino)-l,2-propanediol exhibit a transient smectic A phase on supercooling of the isotropic liquid, whereas 3-(hexy1thio)-1,2-propanediol through 3-( nonylthi0)--1,2-propanediol form smectic phases that are quite stable. Although the thermal behavior in the pure form differs considerably, all three classes of compounds are capable of lyotropic mesophase formation in the presence of water.

Liquid Crystalline Primary Benzamides

“…[1][2][3][4][5][6][7][8][9] Mesogens, containing secondary and tertiary amide groups have been known for a long time.1°-17 Until now, primary mesogenic benzamides have not been described in the literature.…”

Mesomorphic amino sugars

“…There are a few examples of synthetic liquid crystalline amino sugars known at present: N-alkylglucosylamines [ 3 ] , N-alkyl-1 -aminoglycerides [4] and N-alkylglucamines [3,5]. In all of these compounds, the secondary amino group is the bridge between the hydrophilic and the hydrophobic part, A direct comparison with ether analogues is possible for the alkylglucamines and the 1-sorbitol ethers [6] only.…”

Chemical Structure and Mesogenic Properties

“…Compound 26 [255] In recent years many different diols (e.g. [258][259][260][261]), tetraols [262-2651 and polyols (mainly derived from sugars [266][267][268][269][270]270 a]) have been synthesized. Compounds of these classes are amphiphilic.…”