Hybrid liquid crystals tetrazolyl and isoxazolyl cinnamates

被引：19

作者：

Da Rosa, Rafaela R. ^{[1
]}

Tariq, Muhammad ^{[1
,2
,4
]}

Weber, Caroline S. B. ^{[1
]}

Hameed, Shahid ^{[2
]}

Silva, Sidnei ^{[3
]}

Merlo, Aloir A. ^{[1
]}

机构：

[1] Univ Fed Rio Grande do Sul, Inst Chem, Porto Alegre, RS, Brazil

[2] Quaid I Azam Univ, Dept Chem, Islamabad, Pakistan

[3] Univ Caxias do Sul, Lab Nat & Synthet Prod, Caxias Do Sul, Brazil

[4] Shaheed BB Univ Sheringal Dir U, Dept Chem, Sheringal, Pakistan

来源：

LIQUID CRYSTALS | 2016年 / 43卷 / 11期

关键词：

Hybrid liquid crystals; cinnamic acid esters; isoxazoles; tetrazoles; 3+2] 1-3dipolar cycloaddition; LATERAL METHYL-GROUP; MESOMORPHIC BEHAVIOR; PYRIDYL; DIMERS; ACIDS;

D O I：

10.1080/02678292.2016.1193908

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

In this work, a series of isoxazolyl and tetrazolylcinnamic ester hybrid liquid crystals (HLCs) were synthesised and their mesomorphic behaviour was analysed. Cinnamic acid derivatives were prepared by Knoevenagel condensation of malonic acid and arylaldehydes. Five-membered tetrazoles and isoxazoles were prepared by [3 + 2] 1,3-dipolar cycloaddition. Tetrazoles were synthesised by sodium azide addition to arylnitrile, while isoxazoles were synthetised by arylnitrile oxide addition to alkenes to form isoxazolines, followed by MnO2-oxidation. Tetrazolyltolane compounds were also synthesised and their LC behaviour compared with cinnamic esters. HLCs containing isoxazole rings displayed a large mesophase range with high clearing temperature (T-c), with predominance of smectic mesophases SmA and SmC. The HLCs decomposed upon heating due to their high clearing temperature (>250 degrees C). HLCs with tetrazole rings showed a narrow nematic mesophase range with enantiotropic or monotropic behaviour. [GRAPHICS] .

引用

页码：1659 / 1670

页数：12

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