A New Series of Kinked Liquid Crystals: 2-(6-Alkoxynaphthalen-2-yl)-6-methoxyquinolines

A new series of 2-(6-alkoxynaphthalen-2-yl)-6-methoxyquinolines (nO-NpQOMe, n = 3-8) liquid crystal compounds, a linear molecular structure with two kinks, were synthesized using a short two-step reaction with overall yields between 43% and 58%. Spectral analyses were in accord with the expected structures. Thermotropic behavior of these liquid crystal compounds were investigated using polarized optical microscopy and differential scanning calorimetry. All compounds exhibited purely enantiotropic nematic phase at the medium-high temperature range of 162.4-234.2 °C. However, short ranges of nematic phase, 20.5-16.6 °C at heating and 46.7-37.0 °C at cooling, were observed in these linear liquid-crystalline compounds with two kinks.