The effect of different arms on the properties of chiral branched-arm liquid crystals based on isosorbide as the chiral core |
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Authors: | Xiao-Zhi He Li Han Fan-Bao Meng Mei Tian |
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Institution: | Centre for Molecular Science and Engineering , Northeastern University , Shen-yang , People's Republic of China |
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Abstract: | A new series of two-arm ( MA1 , MA2 ), four-arm ( MA3 ) and six-arm ( MA4 ) chiral liquid crystalline compounds containing isosorbide as the chiral core were synthesised. Four precursors of branched-arm A1–A4 were first obtained, and then were esterised separately with isosorbide to obtain four chiral branched-arm liquid crystals ( MA1–MA4 ). The structure and properties have been characterised. The results show that MA1 was smectic–cholesteric phase with a fan-like and oily streak texture; MA2–MA4 showed a cholesteric phase with oily streak texture, or lined texture and finger print texture. Isosorbide successfully induced a cholesteric phase. The melting point and clearing point values for MA1–MA4 first increased and then decreased. The branched-arm and chiral core quantity affected the liquid crystalline properties. At the same time, the difference in side-arms resulted in different directions of rotation. MA1–MA2 showed right-handed rotation and had selective reflection; MA3–MA4 demonstrated left-handed rotation and did not have selective reflection. |
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Keywords: | branched-arm liquid crystal cholesteric selective reflection synthesis |
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