Crystalline solids consisting of three-dimensional networks of interconnected rigid units are ubiquitous amongst functional materials. In many cases, application-critical properties are sensitive to rigid-unit rotations at low temperature, high pressure or specific stoichiometry. The shared atoms that connect rigid units impose severe constraints on any rotational degrees of freedom, which must then be cooperative throughout the entire network. Successful efforts to identify cooperative-rotational rigid-unit modes (RUMs) in crystals have employed split-atom harmonic potentials, exhaustive testing of the rotational symmetry modes allowed by group representation theory, and even simple geometric considerations. This article presents a purely algebraic approach to RUM identification wherein the conditions of connectedness are used to construct a linear system of equations in the rotational symmetry-mode amplitudes.
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http://dx.doi.org/10.1107/S2053273318009713 | DOI Listing |
Nat Chem
January 2025
Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK.
The creation of hosts capable of accommodating different guest molecules may enable these hosts to play useful roles in chemical purifications, among other applications. Metal-organic cages are excellent hosts for various guests, but they generally incorporate rigid structural units that hinder dynamic adaptation to specific guests. Here we report a conformationally adaptable pseudo-cubic cage that can dynamically increase its cavity volume to fit guests with differing sizes.
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January 2025
College of Chemistry and Chemical Engineering, Hunan University, Hunan 410082, P. R. China.
Supramolecular glass and plastic are a new generation of artificial transparent materials that exhibit excellent optical behavior and processability. However, owing to inherent deficiencies in their mechanical toughness and long-term stability, supramolecular materials lack the potential for functionalization and application. Inspired by the toughening phenomena in biological systems, a synergistic covalent-and-supramolecular polymerization strategy was applied to construct plastic-like supramolecular materials with high transmittance the solvent-free one-pot amidation of thioctic acid and (poly)amines.
View Article and Find Full Text PDFPolymers (Basel)
December 2024
Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA.
The mechanical properties of lignin, an aromatic heteropolymer constituting 20-30% plant biomass, are important to the fabrication and processing of lignin-based sustainable polymeric materials. In this study, atomistic simulations are performed to provide microscopic insights into the mechanics of lignin. Representative samples of miscanthus, spruce, and birch lignin are studied.
View Article and Find Full Text PDFNat Commun
January 2025
Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), Nanjing, China.
Fully π-conjugated polymers consisting of plane and rigid aromatic units present a fantastic optoelectronic property, a promising candidate for printed and flexible optoelectronic devices. However, obtaining high-performance conjugated polymers with an excellent intrinsically flexible and printable capacity is a great challenge due to their inherent coffee-ring effect and brittle properties. Here, we report an asymmetric substitution strategy to improve the printable and stretchable properties of deep-blue light-emitting conjugated polymers with a strong inter-aggregate capillary interaction for flexible printed polymer light-emitting diodes.
View Article and Find Full Text PDFSci Rep
December 2024
Division of Mechatronic Devices, Institute of Mechanical Technology, Poznan University of Technology, 60-965, Poznan, Poland.
Grippers are commonly used as a technological tooling for manipulators. They enable robots to interact with objects in their work area. Grippers have a wide range of differentiation focused on the operation performed and the properties (e.
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