Magnetic-field-induced orientational elastic deformations in the liquid-crystalline compounds modeling polymer chain fragments

For the LC dimers whose mesogenic groups are laterally joined by flexible s pacers, the magnetic-field- induced orientational elastic deformations were studied. The temperature dependences of optical anisotropy and elastic con stants were determined. It was shown that the optical anisotropy and the or ientational order parameter of the nematics studied are controlled not only by the length of a flexible spacer but also by a marked freedom of rotatio n of mesogenic groups about the short axes. Bend and splay elastic constant s and the ratio between them remain unchanged with the increasing length of the central flexible fragment. This fact allows one to conclude that the p roperties of the nematic phases formed by dimers and polymers are rather si milar.