Mesomorphic temperature range

The corresponding Gl and G2 hemi-dendritic systems were also prepared for comparison (Fig. 68) [301]. Similar trends were observed in that the SmA phase was preferred to the nematic phase, suppressed upon the insertion of Ceo- The same type of supramolecular organizations is suggested. Interestingly, the mesomorphic temperature range was strongly reduced in the hemi-dendrimers compared to that of the corresponding dendrimers. It was... 

Funahashi, M. and Hanna, J., High carrier mobility up to 0.1 cm(2)/Vs and a wide mesomorphic temperature range of alkynyl-substituted terthiophene and quater-thiophene derivatives. Mol. Crystl. Liq. Crystl. 436, 1179-1189, 2005. 

The mesomorphic properties of hydrogen-bonded mesogens have been compared [40] with those of covalently bonded compounds 16 and 17 [42] (Fig. 6 and Table 2). The melting and isotropization temperatures of the complexes are lower than those of ester compounds, which leads to wider and lower mesomorphic temperature ranges [40]. Moreover, smectic mesophases are observed for fluorinated H-bonded complex 15. 

The mesomorphism of a series of 4-alkoxy-3-fluorodithiobenzoates of nickel, palladium, and zinc was studied. Fluorination in the 3-position was found to promote SmC phase at the expense of the nematic phase with respect to the non-fluorinated analog. Moreover, while the mesomorphic temperature range of the nickel complexes was reduced slightly, it increased in the palladium complexes. Unidentified mesomorphic behavior was observed for the zinc complexes. 

From this systematic study, it appeared that the tetra-alkoxy systems exhibited wider mesomorphic temperature ranges than the dialkoxy-dialkyl complexes and, since the melting points were similar, the mesophase stability was enhanced greatly in the former compared to the latter. 

The induction or stabilization of liquid-crystalline phases in binary CT systems, where the donor and the acceptor compounds are rod-shaped, has been utilized in the design of polymers to enhance their mesomorphic properties the combination of mesomorphic properties and those of polymeric systems, e.g., glassy behavior, has attracted interest due to possible applications, for example, in the field of nonlinear optics. Side-chain copolymers with a polyester or polyacrylate backbone containing 4-me-thoxyazobenzene and 4-cyanoazobenzene units, for example, show the formation of an SmA phase with an enhanced mesomorphic temperature range [30]. Similar behavior is observed for copolystyrene derivatives carrying electron-rich donor units (4-methoxy-... 

Both LCPO-1 and LCPO-2 were found to be liquid crystalline and could be formed into elastic films. Phase transition temperatures of these polymers illustrated in Table 8 show that mesomorphic temperature range (M.R.) of LCPO-2 (78-150 C) is higher and broader than that of LCPO-1 (65-90 0) due to the increase of aromatic groups in the mesogenic groups. 

In this context, a study of the dipolar correlation effect in the mesophase of PDFS is of particular interest [168]. Using this technique, it was concluded that the sample consists of defect-enriched areas and ordered domains. The two dynamic states are connected with segments of different mobility, and they fluctuate temporally and spatially. The exchange times between the two mobihty states range between 0.1 and 1.0 s in the mesomorphic temperature range. 

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