title: Supramolecular Columnar Liquid Crystals with Tapered-Shape Simple Pyrazoles Obtained by Efficient Henry/Michael Reactions.
abstract: 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.
authors.affiliation: Instituto de Ciencia de Materiales de Aragón (ICMA), Dpto de Química Orgánica, Facultad de Ciencias, CSIC-Universidad de Zaragoza, 50009, Zaragoza, Spain.
authors.forename: Hugo
authors.initials: H
authors.lastname: Blanco
authors.affiliation: Instituto de Ciencia de Materiales de Aragón (ICMA), Dpto de Química Orgánica, Facultad de Ciencias, CSIC-Universidad de Zaragoza, 50009, Zaragoza, Spain.
authors.forename: Verónica
authors.initials: V
authors.lastname: Iguarbe
authors.affiliation: Instituto de Ciencia de Materiales de Aragón (ICMA), Dpto de Química Orgánica, Facultad de Ciencias, CSIC-Universidad de Zaragoza, 50009, Zaragoza, Spain.
authors.forename: Joaquín
authors.initials: J
authors.lastname: Barberá
authors.affiliation: Dpto de Química Orgánica, Facultad de Ciencias, Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, 50018, Zaragoza, Spain.
authors.forename: José Luis
authors.initials: JL
authors.lastname: Serrano
authors.affiliation: Dpto de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Facultad de Ciencias, CSIC-Universidad de Zaragoza, 50009, Zaragoza, Spain. anaelduq@unizar.es.
authors.forename: Anabel
authors.initials: A
authors.lastname: Elduque
authors.affiliation: Instituto de Ciencia de Materiales de Aragón (ICMA), Dpto de Química Orgánica, Facultad de Ciencias, CSIC-Universidad de Zaragoza, 50009, Zaragoza, Spain. rgimenez@unizar.es.
authors.forename: Raquel
authors.initials: R
authors.lastname: Giménez
keywords: X-ray diffraction; columnar; liquid crystals; pyrazoles; self-assembly