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Volumn , Issue 15, 2008, Pages 1768-1770

Synthesis and properties of oxadiazole based V-shaped, shape persistent nematogens

Author keywords

[No Author keywords available]

Indexed keywords

OXADIAZOLE DERIVATIVE;

EID: 41549110195     PISSN: 13597345     EISSN: None     Source Type: Journal    
DOI: 10.1039/b718348h     Document Type: Article
Times cited : (37)

References (23)
  • 3
    • 33750871167 scopus 로고    scopus 로고
    • Angew. Chem., Int. Ed. 2005 44 2834
    • G. R. Luckhurst Angew. Chem. 2005 117 2894 Angew. Chem., Int. Ed. 2005 44 2834
    • (2005) Angew. Chem. , vol.117 , pp. 2894
    • Luckhurst, G.R.1
  • 6
    • 0003872521 scopus 로고    scopus 로고
    • D. Demus, G. W. Gray, H.-W. Spiess and V. Vill, VCH, Weinheim, p. 933
    • B. K. Sadashiva, in Handbook of Liquid Crystals, ed., D. Demus,,, G. W. Gray,,, H.-W. Spiess, and, V. Vill,, VCH, Weinheim, 1998, vol. 2B, p. 933
    • (1998) Handbook of Liquid Crystals, Ed.
    • Sadashiva In, B.K.1
  • 16
    • 20444408019 scopus 로고    scopus 로고
    • -1. Thus, their LC (liquid crystal) temperature intervals seem to be larger than that of 1a. However, upon heating of 1b and 1c, the nematic phase crystallises rapidly at 58°C (1b) and 107°C (2c) and, therefore, the nematic phase is clearly monotropic. These compounds also crystallise when slowly cooled in order to orient the materials for conoscopy or X-ray diffraction. In contrast, compound 1a can be kept cooling for at least one hour in the vicinity of the transition temperature without crystallisation and consequently, 1a was studied in detail
    • Y. Cheng T. Luh Macromolecules 2005 38 4563
    • (2005) Macromolecules , vol.38 , pp. 4563
    • Cheng, Y.1    Luh, T.2
  • 17
    • 0042694124 scopus 로고    scopus 로고
    • The birefringence for the aligned sample in Fig. 2c was estimated by means of POM and amounts to Δn = 0.023. The sample is optical negative, which indicates that the short axis of the optical indicatrix (smallest refractive index) is aligned orthogonal to the surface of the substrate. Thus, the value for Δn is presumably not the maximum birefringence of the sample. This is one reason for the higher birefringence in non-aligned samples, as in Fig. 2a. However, in addition, the sample thickness for non-aligned samples was not rigorously controlled. The thickness typically varies between 20-30 μm
    • P. J. H. Kouwer G. H. Mehl J. Am. Chem. Soc. 2003 125 11172
    • (2003) J. Am. Chem. Soc. , vol.125 , pp. 11172
    • Kouwer, P.J.H.1    Mehl, G.H.2
  • 19
    • 0002359880 scopus 로고
    • The correlation length for reflection (i) amounts to ξ(i) = 66 Å; this means that approximately 3-5 molecules are correlated in the direction of the bisect. The correlation length ξ(iii) = 22 Å in the π-π-stacking direction, thus, about 6 molecules are correlated. These values are of short range and in agreement with a nematic phase
    • P. Scherrer Nachr. Ges. Wiss. Göttingen, Math.-Phys. Kl. 1918 2 96
    • (1918) Nachr. Ges. Wiss. Göttingen, Math.-Phys. Kl. , vol.2 , pp. 96
    • Scherrer, P.1


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.