- HEAT CAPACITY AND THERMODYNAMIC PROPERTIES OF P prime -SUBSTITUTED p-n-HEXYLOXYBENZLIDENEANILINES 2. p-n-HEXYLOXYBENZYLIDENEAMINO-p prime -CHLOROBENZENE (HBAC).
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The heat capacity of the smectic liquid crystal, HBAC, were measured from 15 K to 385 K by using an adiabatic calorimeter. Contrary to the previous experimental results on p-n-hexyloxybenzylideneamino-p prime -benzonitrile (HBAB), no solid-solid phase transition was observed in HBAC. However, a new intermediate phase was discovered between the crystal and the smectic B phase. Four phase transitions were found at 327. 7 K (crystal-intermediate phase S//3), 330. 90 K (S//3-smectic B), 362. 98 K (smectic B-smectic A), and 370. 38 K (smectic A-isotropic liquid), respectively. The enthalpies and entropies of these transitions were determined to be 10. 88 kJmol** minus **1/33. 2 JK** minus **1, 12. 35/37. 0, 3. 39/9. 3 and 5. 79/15. 6 respectively. The standard thermodynamic functions have also been estimated up to 385 K. The total sum of four transition entropies amounts to 95. 1 JK** minus **1mol** minus **1 and agrees well with that of three transitions from the crystal II to the isotropic liquid of HBAB.
- Tsuji,Sorai,Suga,Seki
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- Asymmetric Smectogens - 3. Synthesis and Properties of Mesomorphs of Parasubstituted p,n-Alkoxybenzideneanilines.
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The synthesis and characterization of the phases are described together with the determination of the transition temperature for smectic products of the following homolog series: X- phi -N equals CH- phi -0-C//nH//2//n// plus //1 X equals F, Cl, Br, I and
- Seurin,Guillon,Skoulios
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- Liquid Crystalline Properties of N-(4-Alkoxybenzylidene)-4-halogenoanilines
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N-(4-alkoxybenzylidene)-4-halogenoanilines have been synthesized, and phase transitions determined using a differential scanning calorimeter and a polarizing microscope.Smectic and nematic phases have been observed for fluoro and chloro derivatives whereas bromo and iodo derivatives exhibit only a smectic phase.
- Sakagami, Sakumitsu,Nakamizo, Minoru
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p. 265 - 266
(2007/10/02)
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