Shape and orientation of the chiral dipole in ferroelectric liquid crystals studied by solid-state 13C NMR

We report the results of one and two-dimensional solid-state nuclear magnetic resonance measurements in the ferroelectric liquid crystalline phases of a single compound being carbon-13 labeled at the chiral dipole. The shape and orientation of this dipole has been determined from homonuclear dipolar couplings and the chemical shift anisotropy. These investigations open a way for a direct calculation of the lateral dipole moment contributing to the spontaneous polarization. A fast non-biased intramolecular reorientation is established within the ferroelectric liquid crystalline phase. The chiral aliphatic chain is significantly tilted with respect to the director.