Odd‐even effects in polymeric liquid crystals

Semiflexible mesophasic polymers of the general formula {article}{empty}{document}$ {--} [{ OOC(CH}₂ { )}n - 2 - { COO} - { R}^1 {--} ]X ,n = 9,11,13,{--} [{ OOC(CH}₂ )n - 2 - { COO} - { R}^2 {--} ]X ,n = 9,11,13,14, document and articleemptydocument {--} [{ OOCO} - { (CH}₂ { )}n - 4 - { OCOO} - { R}^2 {--} ]X ,n = 9,11,13, document where articleemptydocument { R}¹ = - { C}₆ { H}₅ - { C}({ CH}_3 ) = { CH} - { C}_6 { H}_5 - document and articleemptydocument { R}² = { C}₆ { H}₅ - { C}({ CH}_3 ) = { N} - { N} = ({ CH}_3 ){ C} - { C}_6 { H}_5 - ${document} are prepared and their solid and liquid crystalline behaviour examined and compared to that of the corresponding homologues with n even. Evidence is given of relevant odd‐even effects in the thermodynamic parameters of the clearing transition. The conclusion is drawn in favour of an anisotropic structuration also of the flexible parts of the polymer chain in the liquid crystal phase.