Multifunctional Supramolecular Dendrimers with an s-Triazine Ring as the Central Core: Liquid Crystalline, Fluorescence and Photoconductive Properties

• Published in: Chemistry : a European journal Vol. 20; no. 32; pp. 10027 - 10037
• Main Authors: Bucoş, Madalina, Sierra, Teresa, Golemme, Attilio, Termine, Roberto, Barberá, Joaquín, Giménez, Raquel, Serrano, José Luis, Romero, Pilar, Marcos, Mercedes
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 04.08.2014; WILEY‐VCH Verlag; Wiley; Wiley Subscription Services, Inc
• Subjects: Asymmetry; Chemistry; Chemistry, Multidisciplinary; Dendrimers; Diffraction; Electrochemical analysis; Fluorescence; hydrogen bonds; Liquid crystals; photoconductivity; Physical Sciences; Science & Technology; Spectrum analysis; Symmetry; X-rays; photoconductivity; ROOM-TEMPERATURE; POLYMERS; NONCOVALENT SYNTHESIS; dendrimers; COMPLEXES; hydrogen bonds; 1,3,5-TRIAZINE; TRANSPORT; fluorescence; ORGANIZATIONS; COLUMNAR MESOPHASES; CHEMISTRY; liquid crystals; DERIVATIVES
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201402646

Novel liquid crystal (LC) dendrimers have been synthesised by hydrogen bonding between an s‐triazine as the central core and three peripheral dendrons derived from bis(hydroxymethyl)propionic acid. Symmetric acid dendrons bearing achiral promesogenic units have been synthesised to obtain 3:1 complexes with triazine that exhibit LC properties. Asymmetric dendrons that combine the achiral promesogenic unit and an active moiety derived from coumarin or pyrene structures have been synthesised in order to obtain dendrimers with photophysical and electrochemical properties. The formation of the complexes was confirmed by IR and NMR spectroscopy data. The liquid crystalline properties were investigated by differential scanning calorimetry, polarising optical microscopy and X‐ray diffractometry. All complexes displayed mesogenic properties, which were smectic in the case of symmetric dendrons and their complexes and nematic in the case of asymmetric dendrons and their dendrimers. A supramolecular model for the lamellar mesophase, based mainly on X‐ray diffraction studies, is proposed. The electrochemical behaviour of dendritic complexes was investigated by cyclic voltammetry. The UV/Vis absorption and emission properties of the compounds and the photoconductive properties of the dendrons and dendrimers were also investigated Branch and bind: Luminescence and photoconductivity properties of new supramolecular liquid crystalline dendrimers (see structure) with an s‐1,3,5‐triazine core and fluorescent dendrons incorporated in the periphery are described.