Banana-shaped 1,2,4-oxadiazole analogues of 1,3,4-oxadiazoles

In the last years bent banana-shaped mesomorphic molecules found an increas ingly great interest among theoreticians and experimentalists due to the na ture of this type of liquid crystals to exhibit a spontaneous polarization in the absence of any chiral group in the molecules. Similar property was f ound in mesomorphic 1,3,4-oxadiazoles containing as a central unit the five -membered heterocycle with the Symmetric positions of heteroatoms and as th e link units -the ester groups [1]. In the present work 1,2,4-oxadiazoles - asymmetric isomers of the liquid cr ystals mentioned above, keeping the same banana-shape, were synthesized and their properties were investigated.