The banded texture observed by POM between untreated glass slides for the NF phase of compound It is somewhat surprising that the iodo-terminated 6 exhibits the NF phase, while 7-9 do not; we therefore computed the molecular electrostatic potential on the 0.001 au electron density for each of these compounds (and also RM734). The ESP isosurface of RM734 is as expected, with the nitro-and carboxylate-groups giving rise to regions of enhanced electron density. Materials incorporating a terminal iodo-group feature a large sigma hole -a region of positive charge which can partake in non-covalent interactionswith a smaller feature being seen for the bromo-terminated material (shown in Fig. ). For the fluoro-and chloroterminated materials we do not find such a feature. Experimentally, the observation of an NF phase for the iodo-terminated materials suggests a propensity for head-to-tail ordering which implies the existence of electrostatic interactions between the terminal group and the nitro group at the other terminus.