Whereas compounds 1 and 2 exhibit reductions in clearing points relative to 5OCB we observe that materials with larger cyclic end groups (3 -5) exhibit clearing points notably higher than those of 5OCB. The clearing points correlate with the ring strain of the cyclic end-group; cyclopropane has the lowest clearing point and highest ring strain, whereas cyclohexane has the highest clearing point and lowest ring strain. This enhancement in clearing point is accompanied by an increase in melting point -compounds 1 -5 exhibit higher melting points than the linear parent (5OCB). All five novel materials exhibit nematic phases; however it is surprising to observe a smectic A phase in 5 given the short terminal chain employed. The end-to-end length of all-trans 5 is only slightly larger than 5OCB (18.8 Å versus 17.0 Å, both at the B3LYP/6-31G(d,p) level of DFT). The layer spacing of the SmA phase of 5 was measured to be 31.0 Å and temperature independent when studied by SAXS. The d/l ratio (layer spacing over all-trans molecular length) is therefore 1.65 for 5, this being significantly larger than would be expected for a material with a linear alkoxy chain; for example 8OCB (4-octyloxy-4′-cyanobiphenyl) has a d/l ratio of 1.43. The SmA phase of 5 is therefore interdigitated and thus of the subtype 'SmAd', This interdigitation is common for cyanobiphenyls and results from having molecules form dynamic antiparallel associated pairs through dipole-dipole interactions. The transition temperatures (T, °C) and associated enthalpies (ΔH, kJ mol -1 ) of compounds 1 -5, as determined by DSC at a heat/cool rate of 10 °C min -1 : Values of 5OCB are given for comparison, and were determined by the same method using the same instrument.