C-13 NMR investigation of the crystal to smectic C* phase transition in a ferroelectric liquid crystal

Abstract

We investigated crystal to SmCphase transitions in two kinds of ferroelectric liquid crystals by means of DSC and solid-state C-13 NMR. C-13 CP/MAS NMR measurements indicate that: (1) conformational changes occur in the crystal phase as increasing temperature, (2) overall motion appears in the crystal phase near the transition, and (3) molecular reorientation due to translational disorder occurs at the transition. The structural and dynamic changes in a molecule observed by NMR from the crystalline state to the liquid-crystalline state are discussed in comparisc- with the thermal behavior observed by DSC.