Strained: 6Cycloparaphenylene, a molecule with 97 kcal mol−1 of strain energy, was synthesized. The synthetic strategy relied on two sequential oxidative dearomatization/addition sequences and a ...final reductive aromatization reaction (see scheme). The optoelectronic properties of 6cycloparaphenylene were measured, and the analysis of the X‐ray crystal structure revealed a linear packing geometry reminiscent of a carbon nanotube.
A new material concept of soft crystals is proposed. Soft crystals respond to gentle stimuli such as vapor exposure and rubbing but maintain their structural order and exhibit remarkable visual ...changes in their shape, color, and luminescence. Various interesting examples of soft crystals are introduced in the article. By exploring the interesting formation and phase‐transition phenomena of soft crystals through interdisciplinary collaboration, new materials having both the characteristics of ordered hard crystals and those of flexible soft matter are expected.
Soft crystals respond to gentle stimuli such as vapor exposure and mechanical stimuli but maintain their structural order and exhibit remarkable visual changes in shape, color, and luminescence.
The rational design and synthesis of anisotropic 3D nanostructures with specific composition, morphology, surface structure, and crystal phase is of significant importance for their diverse ...applications. Here, the synthesis of well‐crystalline lotus‐thalamus‐shaped Pt‐Ni anisotropic superstructures (ASs) via a facile one‐pot solvothermal method is reported. The Pt‐Ni ASs with Pt‐rich surface are composed of one Ni‐rich “core” with face‐centered cubic (fcc) phase, Ni‐rich “arms” with hexagonal close‐packed phase protruding from the core, and facet‐selectively grown Pt‐rich “lotus seeds” with fcc phase on the end surfaces of the “arms.” Impressively, these unique Pt‐Ni ASs exhibit superior electrocatalytic activity and stability toward the hydrogen evolution reaction under alkaline conditions compared to commercial Pt/C and previously reported electrocatalysts. The obtained overpotential is as low as 27.7 mV at current density of 10 mA cm−2, and the turnover frequency reaches 18.63 H2 s−1 at the overpotential of 50 mV. This work provides a new strategy for the synthesis of highly anisotropic superstructures with a spatial heterogeneity to boost their promising application in catalytic reactions.
Well‐crystalline lotus‐thalamus‐shaped Pt‐Ni anisotropic superstructures (ASs) with unique hexagonal‐close‐packed/face‐centered‐cubic crystal phases and Pt‐rich surface are synthesized via a simple one‐pot solvothermal method. The obtained Pt‐Ni ASs exhibit superior electrocatalytic activity and stability toward the hydrogen evolution reaction under alkaline conditions compared to commercial Pt/C and other reported electrocatalysts.
•Two selenidostannates Fe1.11Zn0.0.89(en)32Sn2Se6 and Co1.24Zn0.76(en)32Sn2Se6 were solvothermally prepared.•The compounds are consisting of complexes in which the two different transition metals ...occupy the same position and Sn2Se64− anions.•We investigated the photocurrent response of both compounds and found higher transient photocurrent densities.•We also studied the photodegradation efficiency of compounds 1 and 2 and found that the degradation efficiency of two compounds could be achieved 84.5 % and 55.9 %.
In recent decades, chalcogenides have appealed extensive attention due to potential applications in photoelectric materials. Two selenidostannates, Fe1.11Zn0.89(en)32Sn2Se6 (1, en = ethylenediamine) and Co1.24Zn0.76(en)32Sn2Se6 (2) were synthesized by solvothermal method with ethylenediamine and ethylene glycol as the solvents, both consisting of complexes in which the two different transition metals occupied the same position and Sn2Se64− anions. Transition metal complexes (TMCs) can combine photoelectric properties with inorganic skeletons to extend their compound properties. Therefore, we investigated the photocurrent response of both compounds and found higher transient photocurrent densities. The band gaps of compounds 1 and 2 were calculated to be 2.31 eV and 2.17 eV, respectively, indicating that two compounds have potential semiconductor properties. In addition, we also studied the photodegradation efficiency of compounds 1 and 2 and found that the degradation efficiency of two compounds could be achieved 84.5 % and 55.9 %, which indicated that the compounds have excellent photocatalytic properties. The field of photoelectrocatalytic research on selenidostannates is broadened.
Two selenidostannates, Fe1.11Zn0.89(en)32Sn2Se6 (1, en = ethylenediamine) and Co1.24Zn0.76(en)32Sn2Se6 (2), were synthesized under solvothermal conditions using ethylenediamine and ethylene glycol as the solvents. Both consisting of complexes in which the two different transition metals occupied the same position and Sn2Se64− anions, and we investigated the photocurrent response of both compounds and found higher transient photocurrent densities. In addition, we also studied the photodegradation efficiency of compounds 1 and 2 and found that the degradation efficiency of the two compounds could be achieved 84.5 % and 55.9 %. Display omitted
Crystal clear: The title macrocycle was constructed by a nickel‐mediated shotgun macrocyclization. The X‐ray crystallographic structure of 12CPP revealed a circular structure incorporating two ...cyclohexane molecules within the ring. The 12CPP molecules were also found to crystallize into tubular and herringbone structures.
•A novel zirconium complex was synthesized under solvothermal system.•The crystals of zirconium complex exhibit blue luminescence.•The zirconium complex is highly selective and sensitive to detection ...of Co2+ ions.
A novel blue emission of zirconium complex, formulated as Zr(pydc)3·(CH3)2NH22 (1), has been synthesized by using a mixture of zirconium nitrate and 2, 6-pyridinedicarboxylic acid (H2). The complex 1 presents a three-dimensional supramolecular network structure due to the intermolecular N—H···O, O—H···O hydrogen bonds. Additionally, the crystals of 1 exhibit blue luminescence and demonstrate a highly selective and sensitive sensing capability for detection of Co2+ ions with a Ksv value of 1.22 ×104 M−1 and limit of detection (LOD) of 1.20 × 10−5 M. Furthermore, the fluorescence lifetime and quantum yield of the complex 1 is τ= 6.22 μs and Φ= 25.9 %.
a novel blue emission of zirconium complex has been synthesized with selective and sensitive sensing capability for detection of Co2+ ion. Display omitted
Hereditary transthyretin amyloidosis (ATTR) is a disease characterized by the extracellular deposition of transthyretin (TTR) amyloid fibrils. Highly destabilizing TTR mutations cause leptomeningeal ...amyloidosis, a rare, but fatal, disorder in which TTR aggregates in the brain. The disease remains intractable, since liver transplantation, the reference therapy for systemic ATTR, does not stop mutant TTR production in the brain. In addition, despite current pharmacological strategies have shown to be effective against in vivo TTR aggregation by stabilizing the tetramer native structure and precluding its dissociation, they display low brain permeability. Recently, we have repurposed tolcapone as a molecule to treat systemic ATTR. Crystal structures and biophysical analysis converge to demonstrate that tolcapone binds with high affinity and specificity to three unstable leptomeningeal TTR variants, stabilizing them and, consequently, inhibiting their aggregation. Because tolcapone is an FDA‐approved drug that crosses the blood–brain barrier, our results suggest that it can translate into a first disease‐modifying therapy for leptomeningeal amyloidosis.
Databases
PDB codes for A25T‐TTR, V30G‐TTR, and Y114C‐TTR bound to tolcapone are 6TXV, 6TXW, and 6XTK, respectively.
Transthyretin deposition in brain causes leptomeningeal amyloidosis, a fatal and intractable disorder. In this work, we demonstrate that tolcapone, a brain‐permeable and FDA‐approved drug, binds to three highly destabilized leptomeningeal amyloidosis‐associated transthyretin variants with high affinity, stabilizing them and preventing their subsequent aggregation. Overall, the data obtained from crystallographic and biophysical experiments highlight the potential of tolcapone to become a first disease‐modifying molecule to treat leptomeningeal amyloidosis.
Glycine, the simplest amino acid, is also the most polymorphous. Herein, we report the structure determination of a long unknown phase of glycine, which was first reported by Pyne and Suryanarayanan ...in 2001. To date, this phase has only been prepared at 208 K as nanocrystals within ice. Through computational crystal‐structure prediction and powder X‐ray diffraction methods, we identified this elusive phase as glycine dihydrate (GDH), representing the first report on the structure of a hydrated glycine structure. The structure of GDH has important implications for the state of glycine in aqueous solution and the mechanisms of glycine crystallization. GDH may also be the form of glycine that comes to Earth from extraterrestrial sources.
The crystal structure of glycine dihydrate was predicted by computational methods and confirmed by Rietveld refinement of synchrotron X‐ray powder diffraction data. The discovery of this elusive phase improves our understanding of glycine crystallization from aqueous solution. It is suggested that this is the phase adopted by glycine in comets.
The crystal structure of the Δ,Δ enantiomer of the binuclear “light‐switch” ruthenium complex μ‐(11,11′‐bidppz)(1,10‐phenanthroline)4 Ru24+ bound to the oligonucleotide d(CGTACG) shows that one dppz ...moiety of the dumbbell‐like compound inserts into the DNA stack through the extrusion of an AT base pair. The second dppz moiety recruits a neighboring DNA molecule, and the complex thus cross‐links two adjacent duplexes by bridging their major grooves.
Pinned together by molecular rivets: The crystal structure of the complex between double‐stranded DNA and the binuclear complex μ‐(11,11′‐bidppz)(1,10‐phenanthroline)4 Ru24+ (1, shown in blue; bidppz=bis(dipyridophenazine)), showed that one half of the bidppz ligand inserts into a DNA duplex, and the other half stacks onto the blunt end of a nearby DNA duplex. Two molecules of 1 with the same binding mode effectively cross‐link two DNA duplexes.
The Mn12O12(O2CR)16(H2O)4−.2− family of single-molecule magnets has been expanded with new members and the crystal structures of (PPh4)Mn12O12(O2CCHCl2)16(H2O)4 and (PPh4)2Mn12O12(O2CCH2Cl)16(H2O)3. ...Crystals as grown exhibit three and two forms, respectively, with different relaxation rates, which collapse to a single form on vacuum-drying. This emphasizes a high sensitivity of the magnetic properties of such ultra-small nanomagnets to environmental influences.
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•New reduced versions of Mn12 single-molecule magnets have been synthesized.•Crystal structures of one Mn12− and one Mn122− salt have been obtained.•Remarkable sensitivity of the magnetic properties has been revealed by single-crystal hysteresis loop studies.•High sensitivity of ultra-small magnets to their solvation environment is an important factor in their potential application.
The family of reduced Mn12O12(O2CR)16(H2O)4n− (n = 1, 2) single-molecule magnets (SMMs) has been expanded with the synthesis of new members using I− as a stoichiometric one-electron reducing agent of the neutral n = 0 complexes. Electrochemical data, 1H NMR spectra of the Mn12O12(O2CCH2Cl)16(H2O)30,−,2− salts, and the crystal structures of two complexes, (PPh4)Mn12O12(O2CCHCl2)16(H2O)4 and (PPh4)2Mn12O12(O2CCH2Cl)16(H2O)3 have been obtained. For (PPh4)2Mn12O12(O2CCH2Cl)16(H2O)3, the data confirm an S = 10 ground state, and magnetization vs dc field scans on a pristine crystal exhibit hysteresis loops possessing steps due to quantum tunneling of magnetization (QTM). In addition, two forms of the cluster have been identified in the crystal with distinctly different relaxation barriers, with the faster-relaxing form being the majority one in pristine crystals from mother liquor, and the slower-relaxing one becoming the majority one in vacuum-dried samples. Similar behavior is seen for (PPh4)Mn12O12(O2CCHCl2)16(H2O)4 with an S = 19/2 ground state, which shows three forms to be present in the hysteresis loops of a pristine crystal, all converting to a slow-relaxing form on vacuum-drying. High-frequency EPR spectra of the latter confirm a high axial anisotropy with D = −0.477 cm−1 and rationalize its effective relaxation barrier Ueff = 57 K. The combined work emphasizes a high sensitivity of such ultra-small nanomagnets to environmental influences, affecting their properties significantly, especially their quantum properties that are so important to many potential new 21st century applications.
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