In an earlier study by van Hecke et al., it was shown that the discoti
c mesogen hexa-octanoyloxytriphenylene (HAT8) crystallizes in four dif
ferent solid forms, depending on the thermal history of the sample. Th
e present study is an attempt to characterize three of these solids in
more detail using X-ray, carbon-13 and deuterium NMR techniques. It i
s shown that van Hecke's modification IV is a metastable amorphic soli
d, while modifications III and II are highly ordered crystalline solid
s. Both are apparently monoclinic, but with different unit cell dimens
ions. In all solid phases, the triphenylene core is static on the NMR
time-scale, but the side chains are disordered to different degrees in
the different modifications. Further NMR studies on the discotic meso
phase of HAT8 are also reported.