As shown in Fig. 7A, the photoluminescence spectral shape
and emission maxima of complex 1b in the crystalline phases
(Cr1 and Crx) were the same as those in the SmC phase upon
heating. However, in the crystalline phase (Crx) obtained aer
recrystallisation from the melt aer cooling, the emission
maximum was shied by 35 nm to a longer wavelength, which
was accompanied by a change in the spectral shape. When the
Crx crystal phase was melted again to yield the SmC phase, the
emission maximum and spectral shape returned to the initial
state. The Commission Internationale de l'Eclairage (CIE)
chromaticity diagram allows for quantitative evaluation of
photoluminescence colour as shown in Fig. 7B. The luminescence
colour was deep blue in the Cr1 and SmC phases, and was
pale bluish-green in the Crx phase: the CIE coordinates (x, y)
were (0.17, 0.10) in the Cr1 phase at 40 C on rst heating, (0.18,