Nuclear magnetic resonance study of the smectic-cholesteric phase transition in a dimesogenic liquid crystal

• NMR employed to study smectic-chiral nematic phase transition in a dimesogenic liquid crystal.
• Temperature-dependent smectic order parameter obtained by 2H NMR quadrupole splitting.
• Order parameters in different phases obtained from 13C NMR chemical shifts.

Nuclear magnetic resonance (NMR) spectroscopy has provided a unique opportunity to study the characteristic smectic-A to chiral nematic phase transition in a dimesogenic liquid crystal (“KI-5S”). The order parameters in the liquid crystalline phases were obtained from the 2H NMR quadrupole splitting and 13C NMR chemical shift measurements, manifesting a first-order smectic-nematic phase transition.