Mesogenic aromatic-aliphatic azomethine

Solid-State Structures of a Homologous Series of Mesogenic Aromatic—Aliphatic Azomethine Ether Polymers... 

The solid state structure of a homologous series of mesogenic aromatic-aliphatic azomethine ether polymers (AZMEP-n), with n (=1-16) methylene spacers in the main chain, has been studied by X-ray fiber diffraction techniques. Unit cell parameters determined from the fiber patterns of heat-treated single filaments have been used to classify the polymers into distinct groups having different chain conformations and crystal systems. The even members of the. series, where n = 2 4, have C-centered monoclinic unit cells while the unit cells for polymers with n = 6 8 are I-centered monoclinic. When n is even and 10 the unit cells are (primitive) triclinic. The fiber repeat, in the triclinic cells correspond to one chemical moiety while in the monoclinic cells the fiber repeat corresponds to two chemical residues. In addition, the fiber repeat distances are consistent with the methylene spacers adopting an all-trans conformation for all even AZMEP-n polymers. 

BISWAS ET AL. Mesogenic Aromatic—Aliphatic Azomethine Ether Polymers 257... 

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