CPI (complementary polytopic interaction) stabilised liquid crystal compounds formed by esters of 2hydroxy3,6,7,10,11pentakis(hexyloxy)triphenylene

An improved synthesis of 2-hydroxy-3,6,7,10,11-pentakis(hexyloxy)triphenylene 6 is reported which is based on the oxidative coupling of 2-acetoxy-1-hexyloxybenzene 3 to 3,3′,4,4′-tetrakis(hexyloxy)biphenyl 4. Most of the esters of this phenol 7–15, give an enantiotopic Colh columnar liquid crystal phase, which is stable over a wide temperature interval. This can be further enhanced by formation of 1 ∶ 1 CPI compounds with either 2,3,6,7,10,11-hexakis(4-nonylphenyl)triphenylene {PTP9} 1 or hexakis(4-nonylphenyl)dipyrazino[2,3-f:2′,3′-h]quinoxaline {PDQ9} 2. As with other triphenylene derivatives, these additives can also be used to induce liquid crystal behaviour in otherwise non-mesogenic esters.