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Torvid Feiler

Other affiliations: Humboldt University of Berlin
Bio: Torvid Feiler is an academic researcher from Bundesanstalt für Materialforschung und -prüfung. The author has contributed to research in topics: Hydantoin & Raman spectroscopy. The author has an hindex of 1, co-authored 2 publications receiving 3 citations. Previous affiliations of Torvid Feiler include Humboldt University of Berlin.

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TL;DR: In this article, two new polymorphic forms of CPMBP were obtained from a solution and fully characterised using a combination of experiments and density functional theory simulations, and the results demonstrated that polymorph engineering would be a promising avenue to achieve concurrent modulation of optical and mechanical properties of photoluminescent molecular crystals for next-generation flexible optical device applications.
Abstract: The ability to selectively tune the optical and the mechanical properties of organic molecular crystals offers a promising approach towards developing flexible optical devices. These functional properties are sensitive to crystallographic packing features and are hence expected to vary with polymorphic modification. Using as a model system the photoluminescent material 4-bromo-6-[(6-chloropyridin-2-ylimino)methyl]phenol (CPMBP), we herein demonstrate the simultaneous tuning of mechanical flexibility and photoluminescence properties via polymorphism. Two new polymorphic forms of CPMBP were obtained from a solution and fully characterised using a combination of experiments and density functional theory simulations. These polymorphic forms exhibit remarkably distinct mechanical properties and an order of magnitude difference in photoluminescence quantum yield. The mechanically plastic form has a higher quantum yield than the brittle polymorphic form. However, their photoluminescence emission profile is largely unaffected by the observed polymorphism, thereby demonstrating that the optical properties and bulk mechanical properties can in principle be tuned independently. By distinguishing between active (involving absorption and emission) and passive (involving no absorption) light propagation, the waveguiding properties of the plastic form of CPMBP (form II) were explored using the straight and bent crystals to highlight the potential applications of CPMBP in designing flexible optical devices. Our results demonstrated that polymorph engineering would be a promising avenue to achieve concurrent modulation of the optical and mechanical properties of photoluminescent molecular crystals for next-generation flexible optical device applications.

20 citations


Cited by
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Journal ArticleDOI
06 Feb 2022
TL;DR: The continued development and use of time-resolved in-situ (TRIS) approaches to monitor mechanochemical reactions provides a new dimension to elucidate these fascinating transformations as discussed by the authors .
Abstract: Abstract Mechanochemical transformations offer environmentally benign synthesis routes, whilst enhancing both the speed and selectivity of reactions. In this regard, mechanochemistry promises to transform the way in which chemistry is done in both academia and industry but is greatly hindered by a current lack of mechanistic understanding. The continued development and use of time‐resolved in situ (TRIS) approaches to monitor mechanochemical reactions provides a new dimension to elucidate these fascinating transformations. We here discuss recent trends in method development that have pushed the boundaries of mechanochemical research. New features of mechanochemical reactions obtained by TRIS techniques are subsequently discussed, which sheds light on how different TRIS approaches have been used. Emphasis is placed on the strength of combining complementary techniques. Finally, we outline our views on the potential of TRIS methods in mechanochemical research, towards establishing a new, environmentally benign paradigm in the chemical sciences.

36 citations

Journal ArticleDOI
Qi Di1, Jiaqi Li1, Zhanrui Zhang1, Xu Yu1, Baolei Tang1, Houyu Zhang1, Hongyu Zhang1 
TL;DR: In this article, an organic crystal with the ability of elastic bending and plastic twisting upon loading stress and shearing force, respectively, was reported, which enables the crystal to be a model for tensile-responsive study.
Abstract: Organic crystals with mechanical stimulus-response properties are being developed increasingly nowadays. However, the studies involving tensile-responsive crystals are still lacking due to the strict requirement of crystals with good flexibility. In this work, an organic crystal with the ability of elastic bending and plastic twisting upon loading stress and shearing force, respectively, is reported. The deformability in different directions enables the crystal to be a model for tensile-responsive study. Indeed, blue shifts of fluorescence were observed when the tensile forces loaded upon the needle-shaped crystal were stretched to a certain degree. The mathematical correlation between emission wavelength changes and stretching strain was obtained for the first time, which proves that the crystal has a potential application for tension sensors. In addition, a low detection limit and high sensitivity enabled the crystal to have the ability to detect tension variations in precision instruments. Theoretical calculations and X-ray crystal structure analyses revealed the mechanism of emission wavelength shifts caused by molecular movement during the stretching process. The presented crystal successfully overcame the limitations of traditional mechanochromic organic crystals, which have difficulty in responding to tensile forces.

23 citations

Journal ArticleDOI
TL;DR: In this article, an anthracene derivative, 9-anthraldehyde, which can respond to mechanical force and light was reported, which possesses two-dimensional (2D) elastic bending, plastic twisting and photoinduced bending properties.
Abstract: Stimuli-responsive crystals have aroused tremendous interest due to their potential as smart materials. However, endowing mono-component crystals with multiple stimuli-responsive and multifunction properties is still a great challenge. Here, we report an anthracene derivative, 9-anthraldehyde, which can respond to mechanical force and light. It possesses two-dimensional (2D) elastic bending, plastic twisting and photoinduced bending properties. Unusual elastic bending of the plastic twisted crystal was achieved in one crystal. The crystal obtained in this work is a multi-dimensional elastic crystal, which is different from reported twistable materials. To reveal the mechanisms of the properties of 2D elastic bending, plastic twisting and photoinduced bending, nanoindentation tests, energy framework analysis and Hirshfeld surface analysis were used to study the property–structure relationship at the molecular level. It was found that these properties can be ascribed to the unique intermolecular interactions and types of molecular arrangement.

18 citations

Journal ArticleDOI
TL;DR: In this paper , the authors applied in situ monitoring by Raman spectroscopy to the mechanosynthesis of phenytoin, a World Health Organization (WHO) Essential Medicine, enabling the observation, isolation, and characterization of key molecular-migration intermediates involved in the single-step transformation of benzil, urea, and KOH into phenyltoin.
Abstract: In recent years, mechanochemistry has enriched the toolbox of synthetic chemists, enabling faster and more sustainable access to new materials and existing products, including active pharmaceutical ingredients (APIs). However, molecular-level understanding of most mechanochemical reactions remains limited, delaying the implementation of mechanochemistry in industrial applications. Herein, we have applied in situ monitoring by Raman spectroscopy to the mechanosynthesis of phenytoin, a World Health Organization (WHO) Essential Medicine, enabling the observation, isolation, and characterization of key molecular-migration intermediates involved in the single-step transformation of benzil, urea, and KOH into phenytoin. This work contributes to the elucidation of a reaction mechanism that has been subjected to a number of interpretations over time and paints a clear picture of how mechanosynthesis can be applied and optimized for the preparation of added-value molecules.

13 citations

Journal ArticleDOI
TL;DR: In this article , the use of mechanical force produced by milling, grinding, or extruding, as an activation technique, provides access to chemical entities of all kinds, including heterocyclic compounds, metal complexes and peptides.

10 citations