Addressing non‐idealities in NMR experiments on rotating liquid crystals
Unequivocal evidence for a biaxial nematic phase in low-molar-mass calamitic thermotropic liquid crystals has been challenging to generate. Recently we provided NMR evidence that nonlinear calamitic mesogens based on the oxadiazole heterocycle exhibit a biaxial nematic phase ( Phys.
Rev. Lett ., 2004, 92, 145505). Herein we probe the robustness of that claim by exploring potential variations of the director distribution from the ideal one that would apply to nematics rotated about an axis perpendicular to the spectrometer magnetic field. Moreover, we demonstrate that
our methodology, when applied to the high temperature uniaxial nematic TBBA, yields a biaxial order parameter ? = 0.0, thereby confirming the validity of our procedures. Our findings suggest that the original claim of biaxial order (?~0.1) as reflected by probe molecule studies of
oxadiazole mesogens is still valid.
Document Type: Research Article
Affiliations: Department of Chemistry, University of North Carolina, Chapel Hill, 27599 NC
Publication date: 01 November 2005
- Editorial Board
- Information for Authors
- Subscribe to this Title
- Ingenta Connect is not responsible for the content or availability of external websites
- Access Key
- Free content
- Partial Free content
- New content
- Open access content
- Partial Open access content
- Subscribed content
- Partial Subscribed content
- Free trial content