Effect of substituents and alkoxy chain length on the phase behaviour and optical properties of 4-substituted-phenyl 4-alkoxybenzoates

摘要

The refractive indices as functions of temperature were measured for 4-substituted-phenyl 4-alkoxybenzoates in which one substituent is a terminal alkoxy group with the number of carbon atoms kept constant (at n=6, 8, 14, or 16), while the other terminal substituent was either CH_3O, CH_3, Cl, CN or NO_2. Polarizing optical microscopy was also used to identify mesophases and measure their transition temperatures. The results are discussed in terms of electronic polarizability effects.