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1.
Chemistry ; 26(8): 1698-1702, 2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-31997434

RESUMO

The ability to communicate is fundamental to life as we know it and the key to success in many cases is based on having good communication skills. Be it written, spoken, visual, auditory or otherwise, effective communication can open many doors to hidden knowledge that can benefit the world. Science as an entity, which itself stems from the Latin word Scientia, (Engl. "knowledge"), has a tradition of not being particularly well communicated, with long words, vast and confusing concepts, and information overloads. However, as good as communication between scientists has generally become, there is still room for improvement. This article hopes to inform and inspire scientists to lead by example, to educate and advise in the best ways that we can, not just for non-experts, but for the interest of everyone.

2.
Chemphyschem ; 20(17): 2210-2216, 2019 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-31298447

RESUMO

A series of tetraguanidinium tetraphenylethene (TPE) arylsulfonates with different chain lengths was prepared via ionic self-assembly of tetraguanidinium TPE chloride and the respective methyl arylsulfonates. Liquid crystalline properties were studied by differential scanning calorimetry, polarizing optical microscopy and X-ray diffraction. Tetraguanidinium TPE arylsulfonates with chain lengths of C8 -C12 displayed hexagonal columnar mesophases over a broad temperature range, while derivatives with longer chains showed oblique columnar phases. In solution all compounds displayed aggregation-induced emission behaviour. Temperature-dependent luminescence spectra of the bulk phase of the tetraguanidinium TPE arylsulfonate with C14 side chains revealed a strong luminescence both in the solid state and the oblique columnar mesophase. The emission behaviour was rationalized by a unique combination of restriction of intramolecular rotation of the TPE core, Coulomb interaction between the guanidinium cations and π-π interactions of the anionic arylsulfonate moieties.

3.
Chemistry ; 24(69): 18134-18136, 2018 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-30462870

RESUMO

Seeking sustainability: This Special Issue is dedicated to the topic of Renewable Energy. Within this collection of manuscripts are excellent contributions from leading scientists throughout the world who are committed to searching for ways to provide the world with cleaner and greener energy alternatives for a brighter tomorrow.

4.
Dalton Trans ; 47(40): 14340-14351, 2018 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-30187902

RESUMO

Crown ethers and their derivatives are versatile building blocks for the design of supramolecular materials. They can be functionalized at will and are well known for their abilities to complex with alkali cations. Here, we show that emissive lanthanide free hybrid materials can be generated by using such building blocks. The organic tribenzo[18]crown-6 central core was functionalized via six-fold Suzuki cross-coupling as a key reaction with three o-terphenyl units which could be converted into their corresponding triphenylenes by the Scholl reaction, leading to novel liquid-crystalline columnar materials. Selected tribenzo[18]crown-6 o-terphenyls could interact with emissive ternary metal cluster compound salts to generate hybrid materials combining the properties of both moieties. Due to synergistic effects and despite the anisometry of the cluster compounds, individual properties such as liquid-crystalline phase stability of the organic part and emission abilities of its inorganic counter-part are enhanced in the hybrid compounds.

5.
Chemistry ; 22(46): 16494-16504, 2016 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-27734607

RESUMO

Synthetic strategies were developed to prepare l-tyrosine-based ionic liquid crystals with structural variations at the carboxylic and phenolic OH groups as well as the amino functionality. Salt metathesis additionally led to counterion variation. The liquid-crystalline properties were investigated by differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and X-ray diffraction (WAXS, SAXS). The symmetrical ILC chlorides bearing the same alkyl chain at both the ester and ether but either an acyclic or cyclic guanidinium group displayed enantiotropic SmA2 mesophases with phase widths of 31-88 K irrespective of the head group. It was particularly the replacement of chloride in the acyclic guanidinium ILC by hexafluorophosphate that induced a phase change from SmA2 to Colr . This phase change was attributed to a higher curvature of the interface due to the larger anion, which increased the effective head group cross-sectional area of the amphiphilic ILC. The unsymmetrical acyclic guanidinium chlorides, bearing a constant C14 ester and variable alkyl chains on the phenolic position, formed enantiotropic SmA2 phases. The derivative with the largest difference in chain lengths, however, displayed a Colr phase, resulting from discoid aggregates of the cone-shaped guanidinium chloride. The results are discussed in terms of the packing parameters, which indicate that the phase behaviour of the thermotropic tyrosine-based ILCs shows analogies to those of lyotropic liquid crystals.

6.
Soft Matter ; 12(16): 3730-6, 2016 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-26979326

RESUMO

Triphenylbenzenes with different substitution patterns at the outer phenyl rings have been successfully synthesised. Sixfold n-alkoxy substitution was insufficient for mesomorphism, but already increasing the number of side chains by three methoxy groups led to liquid crystalline behaviour and mesophase formation. Symmetrical triphenylbenzenes with nine n-alkoxy side chains (≥C9) formed broad enantiotropic mesophases. The symmetry of the liquid crystalline phases was unambiguously determined by X-ray diffraction measurements as Colh and Colho for symmetry-reduced methoxy-alkoxy derivatives and symmetrical nona-alkoxy-triphenylbenzenes, respectively. Based on X-ray diffraction data a stacking model was proposed in which the single molecules aggregate to helical columns forming a mesophase.

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