Lamellar columnar liquid-crystalline mesophases as a 2D platform for anhydrous proton conduction. Issue 33 (12th August 2019)

• Record Type: Journal Article
• Authors: Cuerva, Cristián; Campo, José A.; Cano, Mercedes; Schmidt, Rainer
• Is Part Of: Journal of materials chemistry. Volume 7:Issue 33(2019)
• Page Start: 10318
• Page End: 10330
• Publication Date: 2019-08-12
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c9tc03627j
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : The fluid properties in the mesophase favour the dissociation of the pyrazole proton, and the metallomesogens behave as water-free proton conductors. Abstract : Several series of dihalide Pd(ii ) compounds bearing pyridyl or isoquinolinylpyrazole ligands have been strategically designed and synthesised to exhibit columnar mesomorphism in wide stability ranges. The coordination of the pyrazoles to the fragments PdX2 (X = Cl, Br, I) generates half-disc molecules that are capable of self-assembling into discotic dimers via intermolecular interactions. This disc-like shape is required for the supramolecular organisation of the lamellar columnar mesophases, which are formed at temperatures below 100 °C in most cases. It was found that these metallomesogens behave as 2D proton conducting materials under anhydrous conditions. The high fluidity properties of the mesophase facilitate proton conduction as a result of the spontaneous dissociation of the acidic pyrazole proton at the melting temperature. For the first time, lamellar columnar mesophases are demonstrated to serve as a 2D platform to induce water-free proton conductivity in dihalide Pd(ii ) metallomesogens.