Effects of a Polar Lateral Nitro Group on the Appearance of Mesophases of 4,4′-Bis(benzoyloxy)biphenyls

Abstract

Four types of 4,4′-bis(benzoyloxy)biphenyls were synthesized to investigate the effects of the lateral polar nitro group on appearance of mesophases as well as improvement of the mesomorphic property. In the case of 4,4′-bis(4-alkoxybenzoyloxy)biphenyls and 4,4′-bis(3,4- and 2,4-dialkoxybenzoyloxy)biphenyls, their transition temperatures were reduced by the introduction of the polar lateral nitro group because of the increasement of the molecular breadth. The nitro group in 4,4′-bis(3,4,5-trialkoxybenzoyloxy)biphenyls enhanced the transition temperatures and mesomorphic properties since the trialkoxy derivatives without a nitro group were not mesomorphic and those with a nitro group had a hexagonal columnar phase. The introduction of the nitro group did not increase the molecular breadth of the trialkoxy derivatives because they already have the wide molecular breadth.

Keywords:

• hexagonal columnar phase
• lateral polar substituent
• substituent effect
• X-ray diffraction study

Notes

Determined by DSC on the second heating.

Determined by DSC on the second heating.

Determined by DSC on the second heating.

Determined by DSC on the first heating.