Synthesis and Properties of a New Family of Chiral Mesogens Containing the 2,3-Dihydrobenzopyran Nucleus
摘要:
A new class of mesogens A with a central chiral core based on the 2,3-dihydrobenzopyran nucleus was synthesized both in the racemic and optically pure form, and the thermotropic properties were studied. The distortion from structural linearity due to the presence of the 2,3-dihydropyran ring does not inhibit the existence of mesophases, and Ch, S-A, and S-C phases were observed according to the substituents present. The conformational constrictions imposed by cyclization proved not to be very important in determining the compactness of the cholesteric helix.