Supramolecular self-assembly of thiol functionalized pentaalkynylbenzene-decorated gold nanoparticles exhibiting a room temperature discotic nematic liquid crystal phase

Abstract

Thiol terminated pentaalkynylbenzene (PA) units were synthesized for coating on gold nanoparticles (GNPs) in order to obtain materials with a combination of the properties of GNPs and discotic nematogens. The PA unit with the longest terminal alkyl spacer was found to exhibit a discotic nematic (N_D) mesophase at room temperature which was preserved even after coating them on GNPs. The effect of GNPs on the orientational order parameter and the dielectric properties of the N_D mesophase have been investigated from various physical measurements. To the best of our knowledge, this is the first example of a room-temperature discotic nematic liquid crystal made of gold nanoparticles.