Contribution of proton NMR relaxation to the investigation of molecular dynamics in columnar mesophases of discotic and polycatenar molecules

Pramana

P J Sebastiao¹  C Cruz¹  A C Ribeiro¹ 

[1] Centro de Fisica da Materia Condensada (UL), Av. Prof. Gama Pinto 2, 1699 Lisboa Cedex, Portugal IST (UTL), Av. Rovisco Pais, 1049-001 Lisboa, Portugal$$

关键词: Liquid crystals;    NMR relaxation;    molecular dynamics.;   

DOI  :  

学科分类：物理（综合）

来源: Indian Academy of Sciences

【 摘 要 】

We present in this work a review concerning wide frequency range 𝑇1 proton NMR relaxation studies performed in compounds exhibiting columnar mesophases, namely the Colho mesophase in the case of a liquid crystal of discotic molecules and the 𝜙h mesophase in the case of a liquid crystal of biforked molecules. These NMR relaxation studies were performed combining conventional and fast field cycling NMR techniques in a frequency range between 100 Hz and 300 MHz. The possibility of probing such a large frequency range has provided a way to effectively distinguish the influence, on the 𝑇1 relaxation profiles, of the different molecular movements observed in this type of mesophases. In addition, we present a comparison between the molecular dynamics in columnar (𝜙h) and lamellar (SmC) mesophases exhibited by the same biforked compound.

【 授权许可】

Unknown