Mesomorphic transformations, alkyl

V. Mesomorphic Transformations and Proton Subsystem Dynamics in Alkyl- and Alkoxybenzoic Acids... 

V. MESOMORPHIC TRANSFORMATIONS AND PROTON SUBSYSTEM DYNAMICS IN ALKYL- AND ALKOXYBENZOIC ACIDS... 

Evidence for polymorphism and possible mesomorphic phases, but not for liquid crystallinity, has been found in studies on methyl, ethyl and propyl stearate (i.e. molecules in which the length of the acid part is maintained at IS carbon atoms and the length of the alcohol part is shorter than in BS) [43,52-55]. We hypothesize that enhanced rotation of an alkoxy group of moderate length in these carboxy-inserted alkanes (perhaps in combination with dipolar effects) includes sufficient disorder within molecular layers to transform the phases from condis to liquid crystals embedding the carboxy group near the middle of an alkane (as with DD) serves to attenuate alkyl chain motions near a layer interface and thus precludes the formation of liquid crystalline phases. These qualitative assertions can and should be tested experimentally using a wider variety of molecules than have been examined thus far. 

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