In this article, we demonstrate a method for inducing reversible crystal-to-crystal transitions in binary mixtures of soft colloidal particles. Through a controlled decrease of salinity and increasingly dominating electrostatic interactions, a single sample is shown to reversibly organize into entropic crystals, electrostatic attraction-dominated crystals, or aggregated gels, which we quantify using microscopy and image analysis. We furthermore analyze crystalline structures with bond order analysis to discern between two crystal phases. We observe the different phases using a sample holder geometry that allows both salinity control and imaging through confocal laser scanning microscopy and apply a synthesis method producing particles with high resolvability in microscopy with control over particle size. The particle softness provides for an enhanced crystallization speed, while altering the re-entrant melting behavior as compared to hard sphere systems. This work thus provides several tools for use in the reproducible manufacture and analysis of binary colloidal crystals.
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http://dx.doi.org/10.1021/acsnano.0c03966 | DOI Listing |
Chemistry
December 2024
Department of Chemistry, Faculty of Science, Shizuoka University, Shizuoka City, Shizuoka, 422-8529, Japan.
A platinum complex equipped with 3-methylbenzofuryl groups was prepared and its crystal structure and emission properties were investigated. This platinum complex has two distinctly emissive polymorphs: a blue-emissive polymorph with low intensity and a brightly green-emissive polymorph. Upon mechanical stimulation, the blue-emitting phase is converted to green-emitting powder through a crystal-to-crystal phase transition.
View Article and Find Full Text PDFJ Phys Chem Lett
October 2024
Geochemical Research Center, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
It is generally believed that ice crystal-to-crystal transitions do not occur below the glass-transition temperature. For instance, under compression, ice I becomes a metastable state but does not transform into other high-pressure ice crystals, and applying excessive pressure ends up causing its collapse into high-density amorphous ice (HDA). Here, we perform molecular dynamics (MD) simulations to demonstrate that a hydrogen-ordered form of cubic ice (ice Ic) transforms to a hydrogen-ordered form of ice IV without yielding HDA.
View Article and Find Full Text PDFJ Am Chem Soc
October 2024
Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, 28049 Madrid, Spain.
The exploration of mechanical motion in molecular crystals under external stimuli is of great interest because of its potential applications in diverse fields, such as electronics, actuation, or sensing. Understanding the underlying processes, including phase transitions and structural changes, is crucial for exploiting the dynamic nature of these crystals. Here, we present a novel organic compound, , consisting of five interconnected aromatic units and two peripheral alkyl chains, which forms crystals that undergo a drastic anisotropic expansion (33% in the length of one of its dimensions) upon thermal stimulation, resulting in a pronounced deformation of their crystal shape.
View Article and Find Full Text PDFDalton Trans
May 2024
Departamento de Química Orgánica e Inorgánica, Facultad de Ciencia y Tecnología, Universidad del País Vasco UPV/EHU, P.O. Box 644, 48080 Bilbao, Spain.
The reaction between neutral bis(picolinate)copper(II) complexes and copper(II)-monosubstituted Keggin-type phosphotungstate anions formed leads to the formation of the hybrid [C(NH)][{PWOCu(HO)}{Cu(pic)}]·10HO compound (1, pic = picolinate) in the presence of structure-directing guanidinium cations. Single-crystal X-ray diffraction studies demonstrate that 1 contains dimeric {PWOCu(HO)}{Cu(pic)} molecular species constituted by two Keggin-type anions linked by one {Cu(pic)} octahedral complex through axial coordination to their terminal oxygen atoms. The extensive hydrogen-bonding network established by guanidium cations and Keggin clusters plays a key role in retaining the crystallinity of the system throughout dehydration to allow a single-crystal-to-single-crystal (SCSC) transformation into the anhydrous [C(NH)][{PWOCu}{Cu(pic)}] (2a) at 170 °C.
View Article and Find Full Text PDFMolecules
December 2023
Faculty of Chemistry, Lomonosov Moscow State University, GSP-1, 1-3 Leninskiye Gory, 119991 Moscow, Russia.
This work presents the synthesis and self-organization of the calamitic fluorinated mesogen, 1,1,2,2-tetrafluoro-2-(1,1,2,2-tetrafluoro-4-iodobutoxy)ethanesulfonic acid, a potential model for perfluorosulfonic acid membranes (PFSA). The compound is derived in three steps from 1,1,2,2-tetrafluoro-2-(1,1,2,2-tetrafluoro-2-iodoethoxy)ethanesulfonyl fluoride, achieving a 78% overall yield. The resulting compound exhibits intricate thermal behavior.
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