A series of novel triphenylenes has been synthesised by a combination of palladium catalysed coupling, oxidative cyclisation, bromination and nucleophilic aromatic substitution. The new derivatives are designed to have structures which are intermediate between the known symmetrical materials hexakis( hexyloxy) triphenylene and hexakis( hexylthio) triphenylene. The compounds having four hexyloxy and two hexylthio substituents form only Col(h) mesophases. Triphenylenes having four hexylthio and two hexyloxy substituents also give Col(h) mesophases but 3,6- bis(hexyloxy)-2,7,10,11-tetrakis(hexylthio) triphenylene 5 is unique in that it cools into a stable, more ordered phase. The low temperature phase, which appears to be indefinitely stable at ambient temperature, is assumed to be helical based on transition enthalpy data.
Probing the structural factors influencing columnar mesophase formation and stability in triphenylene discotics
作者:Andrew N. Cammidge、Céline Chausson、Hemant Gopee、Juanjuan Li、David L. Hughes
DOI:10.1039/b913678a
日期:——
Series of structurally related substituted triphenylene derivatives were designed and synthesised to interrogate key features which determine mesophase formation and stability, and to challenge the general conclusions previously proposed by us and others. It is apparent that no single, simple principle can be universally applied.
The efficient synthesis of fluorous polyaromatichydrocarbons via the arene-fluorine nucleophilic substitution reaction offers a fast and clean synthetic route to highly π-conjugated systems of interest for organic electronics. The development of long-range noncovalent arene-fluoroarene interactions enables the formation of broader and thermally more stable mesophases than their hydrogenated counterparts
SYNTHESIS OF SUBSTITUTED TRIPHENYLENES, USEFUL AS DISCOTIC LIQUID CRYSTALS
申请人:BRITISH TECHNOLOGY GROUP LTD
公开号:EP0703885A1
公开(公告)日:1996-04-03
[EN] SYNTHESIS OF SUBSTITUTED TRIPHENYLENES, USEFUL AS DISCOTIC LIQUID CRYSTALS<br/>[FR] SYNTHESE DE TRIPHENILENES SUBSTITUES UTILES POUR LES CRISTAUX LIQUIDES EN FORME DE DISQUE
申请人:BRITISH TECHNOLOGY GROUP LIMITED
公开号:WO1994029243A1
公开(公告)日:1994-12-22
(EN) Unsymmetrically substituted triphenylenes required in the synthesis of polymeric discotic liquid crystals are made using iron (III) chloride in organic solvent at room temperature to effect the oxidative coupling of 1,2-dialkoxybenzenes to 3,3',4,4'-tetraalkoxybiphenyls. This is followed by a reductive workup. The same oxidation-reduction protocol also proves effective in the trimerisation of 1,2-dialkoxybenzenes.(FR) Les triphénylènes à substitution asymétrique nécessaires à la synthèse des cristaux liquides (en disque) sont obtenus en utilisant du chlorure de fer (III), contenu dans un solvant organique à température ambiante, pour réaliser la liaison oxydante de 1,2-dialkoxybenzènes et de 3,3',4,4'-tétra-alkoxybiphényles. Ceci est suivi d'un bilan réducteur. Le même protocole d'oxydo-réduction a prouvé son efficacité dans la trimérisation des 1,2-dialkoxybenzènes.