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In this paper, the difficulty in orienting the B2phase of the banana mesogen 1,3-Phenylene-bis 4-4-(10-undecenyloxy)-benzoyloxy benzoate (Pbis11BB) in a relatively high magnetic field is reported based on some observations using both 13C and 2H NMR. 2H NMR spectra recorded for the two labeled isotopomers of Pbis11BB in the isotropic and B2phases are shown here. Preliminary results on the deuteron spin−spin relaxation (T2) data are reported at 61 MHz in order to underline the peculiar slow dynamics of banana-shaped liquid crystals (BLC), and these results are discussed in the framework of recent studies on similar BLC. The molecular structure and dynamics in the B2and crystalline phases are also studied by 13C solid-state NMR techniques. The results also point to the slow dynamics in the B2phase of Pbis11BB. In particular, two-dimensional MAS exchange experiment has been performed to shed light on the molecular conformation structure of the five-ring banana core in the crystalline phase of Pbis11BB, and to compare with that of quantum mechanical calculations reported in the literature. [ABSTRACT FROM AUTHOR]

A deuterium two-dimensional exchange NMR technique is used to study the chiral smectic C (SmC*) and chiral subphases (Sm%@mt;sys@%%@ital@%C%@rsf@%%@sx@%Fi1%@be@%*%@sxx@%%@mx@%, Sm%@mt;sys@%%@ital@%C%@rsf@%%@sx@%Fi2%@be@%*%@sxx@%%@mx@%) 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 Sm%@mt;sys@%%@ital@%C%@rsf@%%@sx@%Fi1%@be@%*%@sxx@%%@mx@% and four-layer Sm%@mt;sys@%%@ital@%C%@rsf@%%@sx@%Fi2%@be@%*%@sxx@%%@mx@% 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. [ABSTRACT FROM AUTHOR]