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Anna Worthy

Bio: Anna Worthy is an academic researcher from Queensland University of Technology. The author has contributed to research in topics: Coordination sphere & Elasticity (economics). The author has an hindex of 2, co-authored 2 publications receiving 132 citations.

Papers
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Journal ArticleDOI
TL;DR: Using microfocused synchrotron radiation, it is shown that, under strain, the molecules in the crystal reversibly rotate, and thus reorganize to allow the mechanical compression and expansion required for elasticity and still maintain the integrity of the crystal structure.
Abstract: Single crystals are typically brittle, inelastic materials. Such mechanical responses limit their use in practical applications, particularly in flexible electronics and optical devices. Here we describe single crystals of a well-known coordination compound-copper(II) acetylacetonate-that are flexible enough to be reversibly tied into a knot. Mechanical measurements indicate that the crystals exhibit an elasticity similar to that of soft materials such as nylon, and thus display properties normally associated with both hard and soft matter. Using microfocused synchrotron radiation, we mapped the changes in crystal structure that occur on bending, and determined the mechanism that allows this flexibility with atomic precision. We show that, under strain, the molecules in the crystal reversibly rotate, and thus reorganize to allow the mechanical compression and expansion required for elasticity and still maintain the integrity of the crystal structure.

199 citations

Journal ArticleDOI
TL;DR: In this paper, a methodology for determining the mechanisms of deformation in flexible crystals with atomic precision is described, and examples where it has been implemented and used for application in the determination of mechanisms of flexibility, but great care must be taken during both experimental design and data analysis.
Abstract: While the first report of molecular crystals that could bend without breaking was well over a decade ago, the development of suitable characterisation tools remains a priority. Due to the broad reaching applications of these materials in advanced technologies, it is important to develop both mechanical and mechanistic understanding. Micro-focused mapping experiments were designed with the intent of bridging the gap between the measurement of mechanical properties and molecular-scale structural understanding. Herein, we describe a methodology for determining the mechanisms of deformation in flexible crystals with atomic precision and provide examples where it has been implemented. Although micro-focused mapping experiments have potential for application in the determination of mechanisms of flexibility, great care must be taken during both experimental design and data analysis.

17 citations

Journal ArticleDOI
TL;DR: In this paper , a mechanically flexible one-dimensional coordination polymers exhibiting elastic bending is reported. But such polymers are rare, and they do not have the ability to bend.
Abstract: Coordination polymers exhibiting mechanical flexibility including elastic or plastic bending are rare. Here, we report an example of a mechanically flexible one-dimensional coordination polymer that shows elastic bending. Quantitative insights on the inter and intra-chain bonding as well as structural flexibility from a combination of techniques including variable temperature single crystal X-ray diffraction (XRD), high-pressure crystallography (ambient─15 GPa), synchrotron micro-XRD mapping of the bent crystal, and high-resolution synchrotron X-ray charge density analysis show that the helical coordination polymer behaves like a spring when subjected to external stimuli. Changes that occur with the variation of temperature, pressure, or bending, however, result in very different mechanistic changes. The exceptional coordination sphere flexibility rendered by the presence of Jahn–Teller distorted coordination bonds leads to the flexibility of the polymer.

3 citations


Cited by
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Journal ArticleDOI
TL;DR: This Minireview provides a condensed topical overview of elastic, superelastic, and ferroelastic molecular crystals, new classes of materials that bridge the gap between soft matter and inorganic materials.
Abstract: Mechanically reconfigurable molecular crystals-ordered materials that can adapt to variable operating and environmental conditions by deformation, whereby they attain motility or perform work-are quickly shaping a new research direction in materials science, crystal adaptronics. Properties such as elasticity, superelasticity, and ferroelasticity, which are normally related to inorganic materials, and phenomena such as shape-memory and self-healing effects, which are well-established for soft materials, are increasingly being reported for molecular crystals, yet their mechanism, quantification, and relation to the crystal structure of organic crystals are not immediately apparent. This Minireview provides a condensed topical overview of elastic, superelastic, and ferroelastic molecular crystals, new classes of materials that bridge the gap between soft matter and inorganic materials. The occurrence and detection of these unconventional properties, and the underlying structural features of the related molecular materials are discussed and highlighted with selected prominent recent examples.

178 citations

Journal ArticleDOI
TL;DR: The most recent developments in the research of adaptive molecular crystals are highlighted and their assets and pitfalls are discussed, providing some hints on the likely future developments that capitalize on the untapped, sequestered potential for applications of this distinct materials class.
Abstract: The anticipated shift in the focal point of interest of solid-state chemists, crystal engineers, and crystallographers from structure to properties to function parallels the need to apply our accumulated understanding of the intricacies of crystal structure to explaining the related properties, with the ultimate goal of harnessing that knowledge in applications that require soft, lightweight, or biocompatible organic solids. In these developments, the adaptive molecular crystals warrant particular attention as an alternative choice of materials for light, flexible, and environmentally benign devices, primarily memories, capacitors, sensors, and actuators. Some of the outstanding requirements for the application of these dynamic materials as high-efficiency energy-storage devices are strongly induced polarization, a high switching field, and narrow hysteresis in the case of reversible dynamic processes. However, having been studied almost exclusively by chemists, molecular crystals still lack the appropriate investigations that reliably evaluate their reproducibility, scalability, and actuating performance, and some important drawbacks have diverted the interest of engineers from these materials in applications. United under the umbrella term crystal adaptronics, the recent research efforts aim to realistically assess the appositeness of dynamic crystals for applications that require fast, reversible, and continuous operation over prolonged periods of time. With the aim of highlighting the most recent developments, this Perspective discusses their assets and pitfalls. It also provides some hints on the likely future developments that capitalize on the untapped, sequestered potential of this distinct materials class for applications.

174 citations

Journal ArticleDOI
TL;DR: A rare one-dimensional optical waveguiding crystal of dithieno[3,2-a:2',3'-c]phenazine with high aspect ratio displaying high mechanical flexibility and selective self-absorbance of the blue part of its fluorescence (FL) is presented.
Abstract: We present the one-dimensional optical-waveguiding crystal dithieno[3,2-a:2',3'-c]phenazine with a high aspect ratio, high mechanical flexibility, and selective self-absorbance of the blue part of its fluorescence (FL). While macrocrystals exhibit elasticity, microcrystals deposited at a glass surface behave more like plastic crystals due to significant surface adherence, making them suitable for constructing photonic circuits via micromechanical operation with an atomic-force-microscopy cantilever tip. The flexible crystalline waveguides display optical-path-dependent FL signals at the output termini in both straight and bent configurations, making them appropriate for wavelength-division multiplexing technologies. A reconfigurable 2×2-directional coupler fabricated via micromanipulation by combining two arc-shaped crystals splits the optical signal via evanescent coupling and delivers the signals at two output terminals with different splitting ratios. The presented mechanical micromanipulation technique could also be effectively extended to other flexible crystals.

140 citations

Journal ArticleDOI
TL;DR: Two fluorescent and highly flexible organic crystals (1 and 2) which could bend under an applied stress are reported on, which showed a unique bending mechanofluorochromism.
Abstract: To create low band-gap, fluorescent, and elastic organic crystal emitters, we focused on an extended π-conjugated system based on: a) a planar conformation,b) a rigid structure, and c) controlled intermolecular interactions. Herein, we report on two fluorescent and highly flexible organic crystals (1 and 2) which could bend under an applied stress. The bent crystals rapidly recover their straight shape upon release of the stress. Crystal 1 with a tetrafluoropyridyl terminal unit and a lower band-gap energy (orange emission, λem =573 nm, ΦF =0.50), showed no bending mechanofluorochromism and had superior performance as an optical waveguide with reddish orange emission. The waveguide performance of the crystal did not decrease under bending stress. For crystal 2 with a pentafluorophenyl terminal unit (green emission, λem =500 nm, ΦF =0.38), the original waveguide performance decreased under an applied bending stress; however, this crystal showed a unique bending mechanofluorochromism.

139 citations

Journal ArticleDOI
TL;DR: This prototypical dual-mode organic optical crystalline fiber brings mechanically compliant molecular organic crystals closer to applications as novel light-transducing media for wireless transfer of information in all-organic micro-optoelectronic devices.
Abstract: An anthracene derivative, 9,10-dicyanoanthracene, crystallizes as fluorescent needle-like single crystals that can be readily plastically bent in two directions. Spatially resolved photoluminescence analysis revealed that this material has robust optoelectronic properties that are preserved upon extreme crystal deformation. The highly flexible crystals were successfully tested as efficient switchable optical waveguiding elements for both active and passive light transduction, and the mode of operation depends on the wavelength of the incident light. This prototypical dual-mode organic optical crystalline fiber brings mechanically compliant molecular organic crystals closer to applications as novel light-transducing media for wireless transfer of information in all-organic micro-optoelectronic devices.

138 citations