Dielectric Spectroscopy of Some Nitro Phenyl Hydrazones, with Some Data at Elevated Pressures

Abstract

Dielectric measurements at ambient and elevated pressure confirm the proposal¹, that the two nitrophenylhydrazone compounds studied which display discotic phases, exist as dimers. The dipolar contribution to dielectric permittivity in the solid phase comes mainly from the alkoxy groups, and is augmented in the liquid phases by contributions from the hydrogen bonded o-N0₂ group, The two tailed material with a narrow mesophase exhibits erratic behaviour suggestive of the existence of meta-stable states in the solid phase. The use of a commercial ITO coated cell for the non-discotic compound revealed two separate artefacts which limited the value of the data.