Our official English website, www.x-mol.net, welcomes your
feedback! (Note: you will need to create a separate account there.)
Phase Behavior of a New Class of Anthraquinone-Based Discotic Liquid Crystals
Langmuir ( IF 3.7 ) Pub Date : 2017-11-17 00:00:00 , DOI: 10.1021/acs.langmuir.7b03031 Joydip De 1 , Santosh Prasad Gupta 1 , Indu Bala 1 , Sandeep Kumar 2 , Santanu Kumar Pal 1
Langmuir ( IF 3.7 ) Pub Date : 2017-11-17 00:00:00 , DOI: 10.1021/acs.langmuir.7b03031 Joydip De 1 , Santosh Prasad Gupta 1 , Indu Bala 1 , Sandeep Kumar 2 , Santanu Kumar Pal 1
Affiliation
|
Five novel columnar liquid crystalline compounds (4.1–4.5) consisting of a central anthraquinone core carrying four alkoxy chains (R = n-C6H13, n-C8H17, n-C10H21, n-C12H25, and 3,7-dimethyl octyl) with two diagonally opposite 1-ethynyl-4-pentylbenzene units were synthesized, and their phase transitions were investigated between changes in the molecular structure and their self-assembly into the columnar mesophases. Small and wide-angle X-ray scattering (SAXS/WAXS) studies were performed to deduce the exact nature of the mesophases, and their corresponding electron density maps were derived from the intensities of the peaks observed in the diffraction patterns. A comparison of compounds with different alkoxy chains indicated that the soft crystal columnar rectangular (Crcolrec) phase was stable at lower temperature for the shortest peripheral alkoxy chain (4.1; R = n-C6H13) and was found to exhibit the columnar hexagonal (Colh) phase and then the discotic nematic (ND) phase with increasing temperature. In contrast, increasing the peripheral chain length to n-C8H17 or the branched one (4.2 and 4.5) stabilized the Colh phase at lower temperature and showed the ND phase at higher temperature. Further increase in chain length (4.3 and 4.4; n-C10H21, n-C12H25) demonstrated the formation of the ND phase. Conductivity measurement in the Colh mesophase was found to be almost 10 times higher in magnitude than the corresponding Crcolrec phase. The HOMO–LUMO band gap of all the compounds was found to be in the range from 2.79 to 2.82 eV, which is quite less and comparable with the optical energy band gap.
中文翻译：
新型基于蒽醌的盘状液晶的相行为
五个新颖柱状液晶化合物（4.1 - 4.5）由携带4支烷氧基链（R =中央蒽醌芯的Ñ -C 6 ħ 13，Ñ -C 8 ħ 17，Ñ -C 10 ħ 21，Ñ -C 12 ħ 25合成了具有两个对角相对的1-乙炔基-4-戊基苯单元的3,7-二甲基辛基），并研究了它们在分子结构变化和自组装成柱状中间相之间的相变。进行了小角度和广角X射线散射（SAXS / WAXS）研究，以推断中间相的确切性质，并且从衍射图样中观察到的峰强度得出了它们相应的电子密度图。对具有不同烷氧基链的化合物进行的比较表明，对于较短的外围烷氧基链，软晶柱状矩形（Cr colrec）相在较低温度下是稳定的（4.1； R = n -C 6 H 13），发现随着温度的升高，呈现柱状六方相（Col h），然后呈现盘状向列相（N D）。相反，增加外围链长Ñ -C 8 ħ 17或支链酮（4.2和4.5）稳定山口ħ相在较低温度下，并显示所述N个d相在更高的温度。链长进一步增加（4.3和4.4 ; n -C 10 H 21，n -C 12 H 25）证明了N D相的形成。发现Col h中间相的电导率测量值几乎是相应的Cr colrec相的电导率测量值的10倍。发现所有化合物的HOMO-LUMO带隙在2.79至2.82 eV的范围内，这相当小并且与光能带隙相当。
更新日期：2017-11-19
中文翻译：
新型基于蒽醌的盘状液晶的相行为
五个新颖柱状液晶化合物（4.1 - 4.5）由携带4支烷氧基链（R =中央蒽醌芯的Ñ -C 6 ħ 13，Ñ -C 8 ħ 17，Ñ -C 10 ħ 21，Ñ -C 12 ħ 25合成了具有两个对角相对的1-乙炔基-4-戊基苯单元的3,7-二甲基辛基），并研究了它们在分子结构变化和自组装成柱状中间相之间的相变。进行了小角度和广角X射线散射（SAXS / WAXS）研究，以推断中间相的确切性质，并且从衍射图样中观察到的峰强度得出了它们相应的电子密度图。对具有不同烷氧基链的化合物进行的比较表明，对于较短的外围烷氧基链，软晶柱状矩形（Cr colrec）相在较低温度下是稳定的（4.1； R = n -C 6 H 13），发现随着温度的升高，呈现柱状六方相（Col h），然后呈现盘状向列相（N D）。相反，增加外围链长Ñ -C 8 ħ 17或支链酮（4.2和4.5）稳定山口ħ相在较低温度下，并显示所述N个d相在更高的温度。链长进一步增加（4.3和4.4 ; n -C 10 H 21，n -C 12 H 25）证明了N D相的形成。发现Col h中间相的电导率测量值几乎是相应的Cr colrec相的电导率测量值的10倍。发现所有化合物的HOMO-LUMO带隙在2.79至2.82 eV的范围内，这相当小并且与光能带隙相当。
京公网安备 11010802027423号