2-4 phase transition behavior
thermal decomposition temperature of the synthesized complexes were determined by thermogravimetric differential thermal measurement (TG / DTA).
It should be noted that the 5% weight reduction temperature I was defined as the thermal decomposition temperature. The polarized light microscopy (POM)
we observed a phase transition behavior by observation and differential scanning calorimetry (DSC). Of each complex
a TG / DTA curve Figure 2-3, Figure 2-4, it is shown in Figure 2-5 a polarizing microscope photograph the DSC curve. Or
the phase transition temperature of each complex was determined by these measurements was to Table 2-3 and Figure 2-6, Enta
I show the rupee change and entropy change in Table 2-4. Phase transition results behavior has been observed, achiral complexes having a benzene ring in the core portion but A-Ph6 expressed a liquid crystal phase in a relatively narrow temperature range, chiral was synthesized new gold complex S-Ph6 the liquid crystalline It did not express. General liquid crystal molecules are rigid core sites but with combination of the flexible side chain, A-Ph6 and S-Ph6 choice but no one benzene ring, in order to rigidity of the core sites were not enough, I stable I could not express a liquid crystal phase was considered. So the core site was designed gold complex A-Bi6 and S-Bi6 which was extended in the longitudinal direction place was, but these complexes showed enantiotropic Toro pick liquid crystal, gold complex is the melting point of the A-Bi6 and S-Bi6 very high, liquid crystal temperature range is present in the high-temperature region. Gold complex in the case of practical use of the body as a liquid crystal material, to express a liquid crystal phase at around room temperature is desirable. Comparing the complex obtained by introducing a benzene ring and a biphenyl skeleton, a significant reduction in the melting point observed by introducing a methyl group into flexible strands in either the complex is. In addition, from the crystal structure of the complex with achiral flexible chain, the length of the core site axis and the short axis of the molecular length ratio of, that is, to approximate the aspect ratio (Figure 2-7), the aspect ratio and the melting point, liquid crystal temperature correlation with ranges were observed (Fig. 2-8).
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