Three series of chiral compounds with semifluorinated chains have been synthesized. These compounds were characterized by IR, H-1 NMR, F-19 NMR, MS-mass spectrum, and elemental analysis. Their phase-transition behavior was investigated by DSC-differential scanning calorimetry and polarizing optical microscopy. Both the introduction of a triple bond and lateral difluorosubstitution in the core decrease the clearing points and suppress the formation of the SmC phase.