Interlayer self-diffusion and structure of chiral smectic phases studied by 2H NMR exchange experiment.
A deuterium two-dimensional exchange NMR technique is used to study the chiral smectic C (SmC*) and chiral subphases (SmC*(Fi1), SmC*(Fi2)) of a smectogen (s)-1-methylheptyl 4'-(4-n-decyloxy-benzoyloxy)biphenyl-4-carboxylate (10B1M7). The aim is to demonstrate how this technique can be combined with sample rotation in the magnetic field to obtain the fast translational self-diffusion constant along the helical pitch in the SmC* phase and to shed light on the structure of helicoidal superlattice in the three-layer SmC*(Fi1) and four-layer SmC*(Fi2) phases. The cross-peak intensities in the 2D exchange spectrum are sensitive to the disposition of molecules in the three- and four-layer base unit. The results support the "asymmetric Clock model" as an appropriate description of the ferrielectric phases in this compound.
Department of Physics and Astronomy, University of Manitoba, Winnipeg, MB, Canada R3T 2N2.
Jiadi
J
Xu
Ronald Y
RY
Dong