Grandjean plane texture

Fig.48 The Grandjean plane texture of the chiral nematic phase of supermolecule 43. There is a blue iridescent color which is due to the selective reflection of light from the helical macrostructure (xlOO)...

For compound 23 the uncharacterized phase, denoted as M, was found to be exhibited over a fairly wide temperature range. Ribeiro et al, found that the X-ray diffraction patterns associated with the intermediary phase were typical of a disordered smectic modification. The d spacing of 45.3 A was found to be a little bit shorter than the calculated molecular length which is consistent with the presence of a smectic A phase. As the material also exhibits a Grandjean plane texture it was concluded that the phase must be a TGB modification. However, the platelet/fan texture exhibited by the mesophase conversely suggests that a columnar ordering must be present as well,... 

The mesophase defect textures exhibited by 47 were typical of those normally found for a chiral nematic phase, except they were only revealed upon annealing, which is probably a function of the viscosity of the material. Thus the sample was annealed just below the clearing point. After 24 h, large areas of the preparation evolved to show fingerprint defects and the Grandjean plane... 

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