Blanco Hugo, Iguarbe Verónica, Barberá Joaquín, Serrano José Luis, Elduque Anabel, Giménez Raquel
Instituto de Ciencia de Materiales de Aragón (ICMA), Dpto de Química Orgánica, Facultad de Ciencias, CSIC-Universidad de Zaragoza, 50009, Zaragoza, Spain.
Dpto de Química Orgánica, Facultad de Ciencias, Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, 50018, Zaragoza, Spain.
Chemistry. 2016 Mar 24;22(14):4924-30. doi: 10.1002/chem.201504779. Epub 2016 Feb 18.
A straightforward synthesis of mesogenic pyrazoles starting from benzaldehydes by a combination of efficient Henry and Michael reactions led to novel supramolecular liquid crystals. The mesogens are fluorescent 3,5-dimethyl-4-(di or trialkoxyphenyl)pyrazoles and, in spite of the tapered shape of these molecules and their structural simplicity (only one phenyl ring), columnar liquid-crystal phases were formed that are stable at room temperature. The self-assembled structure was studied by XRD and the columnar cross section contains two molecules on average with an antiparallel arrangement of pyrazoles interacting through hydrogen bonds. In contrast, the single-crystal structure of a trimethoxy analog did not show hydrogen-bonded pyrazoles but chains of head-to-tail arranged molecules.
通过高效的亨利反应和迈克尔反应相结合，从苯甲醛出发直接合成介晶吡唑，得到了新型超分子液晶。这些介晶是荧光性的3,5 - 二甲基 - 4 -（二或三烷氧基苯基）吡唑，尽管这些分子呈锥形且结构简单（只有一个苯环），但仍形成了在室温下稳定的柱状液晶相。通过X射线衍射研究了自组装结构，柱状横截面平均包含两个分子，吡唑通过氢键以反平行排列相互作用。相比之下，三甲氧基类似物的单晶结构并未显示出氢键连接的吡唑，而是头对尾排列的分子链。
