| 1. |
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| 2. |
- Zhang, Qiong, et al.
(författare)
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Working mechanism for a redox switchable molecular machine based on cyclodextrin : a free energy profiles approach
- 2010
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Ingår i: Journal of Physical Chemistry B. - Washington DC, USA : American Chemical Society (ACS). - 1520-6106 .- 1520-5207. ; 114:19, s. 6561-6566
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Tidskriftsartikel (refereegranskat)abstract
- This paper reports the working mechanism for a redox-responsive bistable [2]rotaxane incorporating an alpha-cyclodextrin (alpha-CD) ring (J. Am. Chem. Soc. 2008, 130, 11294-11296), based on free energy profiles obtained from all-atom molecular dynamics simulations. Employing an umbrella sampling technique, the free energy profiles (potential of mean force, PMF) were calculated for the shuttling motion of the alpha-CD ring between a tetrathiafulvalene (TTF) recognition site and a triazole (TZ) unit on the dumbbell of the rotaxane for three oxidation states (0, +1, +2) of the TTF unit. These calculated free energy profiles verified the experimentally observed binding preference for each state. Analysis of the free energy components reveals that, for these alpha-CD-based rotaxanes with charged TTF units, the real driving force for the shuttling in the oxidized states is actually the interactions between water and the rotaxane components, which overwhelms the attractive interactions between the alpha-CD ring and the charged dumbbell. In this work, we put forward a feasible approach to correctly describe the complexation behavior of CD with charged species, that is, free energy profiles obtained from all-atom molecular dynamics simulation.
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| 3. |
- Aisaiti, Adila, et al.
(författare)
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Effect of photobiomodulation therapy on painful temporomandibular disorders
- 2021
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- To evaluate the effect of photobiomodulation therapy (PBMT) on painful temporomandibular disorders (TMD) patients in a randomized, double-blinded, placebo-controlled manner. Participants were divided into a masseter myalgia group (n = 88) and a temporomandibular joint (TMJ) arthralgia group (n = 87) according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Both groups randomly received PBMT or placebo treatment once a day for 7 consecutive days, one session. The PBMT was applied with a gallium-aluminum-arsenide (GaAlAs) laser (wavelength = 810 nm) at pre-determined points in the masseter muscle (6 J/cm2, 3 regions, 60 s) or TMJ region (6 J/cm2, 5 points, 30 s) according to their most painful site. Pain intensity was rated on a 0–10 numerical rating scale (NRS) and pressure pain thresholds (PPT) and mechanical sensitivity mapping were recorded before and after the treatment on day 1 and day 7. Jaw function was assessed by pain free jaw opening, maximum unassisted jaw opening, maximum assisted jaw opening, maximum protrusion and right and left excursion. Data were analyzed with a mixed model analysis of variance (ANOVA). Pain intensity in arthralgia patients decreased over time (P < 0.001) for both types of interventions, however, PBMT caused greater reduction in pain scores than placebo (P = 0.014). For myalgia patients, pain intensity decreased over time (P < 0.001) but without difference between interventions (P = 0.074). PPTs increased in both myalgia (P < 0.001) and TMJ arthralgia patients over time (P < 0.001) but without difference between interventions (P ≥ 0.614). Overall, PBMT was associated with marginally better improvements in range of motion compared to placebo in both myalgia and arthralgia patients. Pain intensity, sensory function and jaw movements improve after both PBMT and placebo treatments in myalgia and arthralgia patients indicating a substantial non-specific effect of PBMT.
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| 4. |
- Bai, Linyi, et al.
(författare)
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Iron( III)-Quantity-Dependent Aggregation-Dispersion Conversion of Functionalized Gold Nanoparticles
- 2014
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Ingår i: Chemistry - A European Journal. - : Wiley. - 0947-6539 .- 1521-3765. ; 20:14, s. 4032-4037
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Tidskriftsartikel (refereegranskat)abstract
- Developing gold nanoparticles (AuNPs) with well-designed functionality is highly desirable for boosting the performance and versatility of inorganic-organic hybrid materials. In an attempt to achieve ion recognition with specific signal expressions, we present here 4-piperazinyl-1,8-naphthalimide-functionalized AuNPs for the realization of quantitative recognition of Fe-III ions with dual (colorimetric and fluorescent) output. The research takes advantage of 1)quantity-controlled chelation-mode transformation of the piperazinyl moiety on the AuNPs towards Fe-III, thereby resulting in an aggregation-dispersion conversion of the AuNPs in solution, and 2)photoinduced electron transfer of a naphthaimide fluorophore on the AuNPs, thus leading to reversible absorption and emission changes. The functional AuNPs are also responsive to pH variations. This strategy for realizing the aggregation-dispersion conversion of AuNPs with returnable signal output might exhibit application potential for advanced nanoscale chemosensors.
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| 5. |
- Jana, Avijit, et al.
(författare)
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Morphology Tuning of Self-Assembled Perylene. Monoimide from Nanoparticles to Colloidosomes with Enhanced Excimeric NIR Emission for Bioimaging
- 2016
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 8:3, s. 2336-2347
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Tidskriftsartikel (refereegranskat)abstract
- Organic near-infrared (NIR) fluorescent probes have been recognized as an emerging class of materials exhibiting a great potential in advanced bioanalytical applications. However, synthesizing such organic probes that could simultaneously work in the NIR spectral range and have large Stokes shift, high stability in biological systems, and high photostability have been proven challenging. In this work, aggregation induced excimeric NIR emission in aqueous media was observed from a suitably substituted perylene monoimide (PeIm) dye. Controlled entrapment of the dye into pluronic F127 micellar system to preserve its monomeric green emission in aqueous media was also established. The aggregation process of the PeIm dye to form organic nanoparticles (NPs) was evaluated experimentally by the means of transmission electron microscope imaging as well as theoretically by the molecular dynamics simulation studies. Tuning the morphology along with the formation of colloidosomes by the controlled self-aggregation of PeIm NPs in aqueous suspension was demonstrated successfully. Finally, both excimeric and monomeric emissive PeIm NPs as well as PeIm colloidosomes were employed for the bioimaging in vitro.
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| 6. |
- Jana, Avijit, et al.
(författare)
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Perylene-Derived Single-Component Organic Nanoparticles with Tunable Emission : Efficient Anticancer Drug Carriers with Real-Time Monitoring of Drug Release
- 2014
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Ingår i: ACS Nano. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 8:6, s. 5939-5952
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Tidskriftsartikel (refereegranskat)abstract
- An organic nanoparticle-based drug delivery system with high drug loading efficacy (similar to 79 wt %) was developed using a perylene-derived photoremovable protecting group, namely, perylene-3,4,9,10-tetrayltetramethanol (Pe(OH)(4)). The anticancer drug chlorambucil was protected by coupling with Pe(OH)(4) to form photocaged nanoparticles (Pe(OH)(4)). The photorelease mechanism of chlorambucil from the Pe(Cbl)(4) conjugate was investigated experimentally by high-resolution mass spectrometry and theoretically by density functional theory calculations. The Pe(Cbl)(4) nanoparticles perform four important roles: (i) a nanocarrier for drug delivery, (ii) a phototrigger for drug release, (iii) a fluorescent chromophore for cell imaging, and (iv) a photoswitchable fluorophore for real-time monitoring of drug release. Tunable emission of the perylene-derived nanoparticles was demonstrated by comparing the emission properties of the Pe(OH)(4) and Pe(Cbl)(4) nanoparticles with perylene-3-ylmethanol. These nanoparticles were subsequently employed in cell imaging for investigating their intracellular localization. Furthermore, the in vivo toxicity of the Pe(OH)(4) nanoparticles was investigated using the mouse model. Histological tissue analysis of five major organs, i.e., heart, kidney, spleen, liver, and lung, indicates that the nanoparticles did not show any obvious damage to these major organs under the experimental conditions. The current research presents a successful example of integrating multiple functions into single-component organic nanoparticles for drug delivery.
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| 7. |
- Li, Pei-Zhou, et al.
(författare)
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A highly porous metal-organic framework for large organic molecule capture and chromatographic separation
- 2017
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Ingår i: Chemical Communications. - : Royal Society of Chemistry (RSC). - 1359-7345 .- 1364-548X. ; 53:24, s. 3434-3437
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Tidskriftsartikel (refereegranskat)abstract
- A highly porous metal-organic framework (MOF) with large pores was successfully obtained via solvothermal assembly of a ''click''-extended tricarboxylate ligand and Zn(II) ions. The inherent feature of large-molecule accessible pores endows the MOF with a unique property for utilization toward large guest molecules.
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| 8. |
- Li, Xin, et al.
(författare)
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Aggregation-induced chiral symmetry breaking of a naphthalimide-cyanostilbene dyad
- 2014
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Ingår i: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry (RSC). - 1463-9076 .- 1463-9084. ; 16:43, s. 23854-23860
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Tidskriftsartikel (refereegranskat)abstract
- Spontaneously emerged supramolecular chirality and chiral symmetry breaking from achiral/racemic constituents remain poorly understood. We here report that supramolecular chirality may emerge from the structural flexibility of achiral aryl nitrogen centres which provide instantaneous chirality. Employing a naphthalimide-cyanostilbene dyad as a model, we explored the underlying mechanism of aggregation-induced chiral symmetry breaking and found that the conformations of the N-naphthylpiperazine and the N, N-dimethylaniline units facilitate the formation of ordered supramolecular structures and offer opposite handedness. Furthermore, chiral symmetry breaking of the monomers was amplified by the formation of dimers. The microscopic and the macroscopic observations from the theoretical simulations and experimental measurements are thus rationalized by connecting the population of the dihedral angles of the aryl nitrogen centres, the morphology of the self-assemblies, and the observed circular dichroism spectra.
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| 9. |
- Li, Yiran, et al.
(författare)
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Photoinduced Radical Emission in a Coassembly System
- 2021
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Ingår i: Angewandte Chemie International Edition. - : John Wiley & Sons. - 1433-7851 .- 1521-3773. ; 60:44, s. 23842-23848
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Tidskriftsartikel (refereegranskat)abstract
- Developing radical emission at ambient conditions is a challenging task since radical species are unstable in air. In the present work, we overcome this challenge by coassembling a series of tricarbonyl-substituted benzene molecules with polyvinyl alcohol (PVA). The strong hydrogen bonds between the guest dopants and the PVA host matrix protect the free radicals of carbonyl compounds after light irradiation, leading to strong solid state free radical emission. Changing temperature and peripheral functional groups of the tricarbonyl-substituted benzenes can influence the intensity of the radical emission. Quantum-chemical calculations predict that such free radical fluorescence originates from anti-Kasha D-2 -> D-0 vertical emission by the anion radicals. The photoinduced radical emission by the tricarbonyl-substituted benzenes was successfully utilized for information encryption application.
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| 10. |
- Liu, Guofeng, et al.
(författare)
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Helicity Inversion of Supramolecular Hydrogels Induced by Achiral Substituents
- 2017
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Ingår i: ACS Nano. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 11:12, s. 11880-11889
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Tidskriftsartikel (refereegranskat)abstract
- Probing the supramolecular chirality of assemblies and controlling their handedness are closely related to the origin of chirality at the supramolecular level and the development of smart materials with desired handedness. However, it remains unclear how achiral residues covalently bonded to chiral amino acids can function in the chirality inversion of supramolecular assemblies. Herein, we report macroscopic chirality and dynamic manipulation of chiroptical activity of hydrogels self-assembled from phenylalanine derivatives, together with the inversion of their handedness achieved solely by exchanging achiral substituents between oligo(ethylene glycol) and carboxylic acid groups. This helicity inversion is mainly induced by distinct stacking mode of the self-assembled building blocks, as collectively confirmed by scanning electron microscopy, circular dichroism, crystallography, and molecular dynamics calculations. Through this straightforward approach, we were able to invert the handedness of helical assemblies by merely exchanging achiral substituents at the terminal of chiral gelators. This work not only presents a feasible strategy to achieve the handedness inversion of helical nanostructures for better understanding of chiral self-assembly process in supramolecular chemistry but also facilities the development of smart materials with controllable handedness in materials science.
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| 11. |
- Ning, Yujie, et al.
(författare)
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Comparative analysis of the gut microbiota composition between knee osteoarthritis and Kashin-Beck disease in Northwest China
- 2022
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Ingår i: Arthritis Research & Therapy. - : BioMed Central. - 1478-6362. ; 24:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Osteoarthritis (OA) and Kashin-Beck disease (KBD) both are two severe osteochondral disorders. In this study, we aimed to compare the gut microbiota structure between OA and KBD patients.Methods: Fecal samples collected from OA and KBD patients were used to characterize the gut microbiota using 16S rDNA gene sequencing. To identify whether gut microbial changes at the species level are associated with the genes or functions of the gut bacteria between OA and KBD groups, metagenomic sequencing of fecal samples from OA and KBD subjects was performed.Results: The OA group was characterized by elevated Epsilonbacteraeota and Firmicutes levels. A total of 52 genera were identified to be significantly differentially abundant between the two groups. The genera Raoultella, Citrobacter, Flavonifractor, g__Lachnospiraceae_UCG-004, and Burkholderia-Caballeronia-Paraburkholderia were more abundant in the OA group. The KBD group was characterized by higher Prevotella_9, Lactobacillus, Coprococcus_2, Senegalimassilia, and Holdemanella. The metagenomic sequencing showed that the Subdoligranulum_sp._APC924/74, Streptococcus_parasanguinis, and Streptococcus_salivarius were significantly increased in abundance in the OA group compared to those in the KBD group, and the species Prevotella_copri, Prevotella_sp._CAG:386, and Prevotella_stercorea were significantly decreased in abundance in the OA group compared to those in the KBD group by using metagenomic sequencing.Conclusion: Our study provides a comprehensive landscape of the gut microbiota between OA and KBD patients and provides clues for better understanding the mechanisms underlying the pathogenesis of OA and KBD.
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| 12. |
- Ning, Yujie, et al.
(författare)
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Genetic Variants and Protein Alterations of Selenium- and T-2 Toxin-Responsive Genes Are Associated With Chondrocytic Damage in Endemic Osteoarthropathy
- 2022
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Ingår i: Frontiers in Genetics. - : Frontiers Media S.A.. - 1664-8021. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- The mechanism of environmental factors in Kashin-Beck disease (KBD) remains unknown. We aimed to identify single nucleotide polymorphisms (SNPs) and protein alterations of selenium- and T-2 toxin-responsive genes to provide new evidence of chondrocytic damage in KBD. This study sampled the cubital venous blood of 258 subjects including 129 sex-matched KBD patients and 129 healthy controls for SNP detection. We applied an additive model, a dominant model, and a recessive model to identify significant SNPs. We then used the Comparative Toxicogenomics Database (CTD) to select selenium- and T-2 toxin-responsive genes with the candidate SNP loci. Finally, immunohistochemistry was applied to verify the protein expression of candidate genes in knee cartilage obtained from 15 subjects including 5 KBD, 5 osteoarthritis (OA), and 5 healthy controls. Forty-nine SNPs were genotyped in the current study. The C allele of rs6494629 was less frequent in KBD than in the controls (OR = 0.63, p = 0.011). Based on the CTD database, PPARG, ADAM12, IL6, SMAD3, and TIMP2 were identified to interact with selenium, sodium selenite, and T-2 toxin. KBD was found to be significantly associated with rs12629751 of PPARG (additive model: OR = 0.46, p = 0.012; dominant model: OR = 0.45, p = 0.049; recessive model: OR = 0.18, p = 0.018), rs1871054 of ADAM12 (dominant model: OR = 2.19, p = 0.022), rs1800796 of IL6 (dominant model: OR = 0.30, p = 0.003), rs6494629 of SMAD3 (additive model: OR = 0.65, p = 0.019; dominant model: OR = 0.52, p = 0.012), and rs4789936 of TIMP2 (recessive model: OR = 5.90, p = 0.024). Immunohistochemistry verified significantly upregulated PPARG, ADAM12, SMAD3, and TIMP2 in KBD compared with OA and normal controls (p < 0.05). Genetic polymorphisms of PPARG, ADAM12, SMAD3, and TIMP2 may contribute to the risk of KBD. These genes could promote the pathogenesis of KBD by disturbing ECM homeostasis.
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| 13. |
- Wu, Hongwei, et al.
(författare)
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Crystal Multi-Conformational Control Through Deformable Carbon-Sulfur Bond for Singlet-Triplet Emissive Tuning
- 2019
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Ingår i: Angewandte Chemie International Edition. - : WILEY-V C H VERLAG GMBH. - 1433-7851 .- 1521-3773. ; 58:13, s. 4328-4333
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Tidskriftsartikel (refereegranskat)abstract
- Crystal-state luminophores have been of great interest in optoelectronics for years, whereas the excited state regulation at the crystal level is still restricted by the lack of control ways. We report that the singlet-triplet emissive property can be profoundly regulated by crystal conformational distortions. Employing fluoro-substituted tetrakis(arylthio)benzene luminophores as prototype, we found that couples of molecular conformations formed during different crystallizations. The deformable carbon-sulphur bond essentially drove the distortion of the molecular conformation and varied the stacking mode, together with diverse non-covalent interactions, leading to the proportional adjustment of the fluorescence and phosphorescence bands. This intrinsic strategy was further applied for solid-state multicolor emissive conversion and mechanoluminescence, probably offering new insights for design of smart crystal luminescent materials.
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| 14. |
- Wu, Hongwei, et al.
(författare)
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Multidimensional Structure Conformation of Persulfurated Benzene for Highly Efficient Phosphorescence
- 2021
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Ingår i: ACS Applied Materials and Interfaces. - : AMER CHEMICAL SOC. - 1944-8244 .- 1944-8252. ; 13:1, s. 1314-1322
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Tidskriftsartikel (refereegranskat)abstract
- It is a challenge to acquire, realize, and comprehend highly emissive phosphorescent molecules. Herein, we report that, using persulfurated benzene compounds as models, phosphorescence can be strongly enhanced through the modification of molecular conformation and crystal growth conditions. By varying the peripheral groups in these compounds, we were able to control their molecular conformation and crystal growth mode, leading to one- (1D), two- (2D), and three-dimensional (3D) crystal morphologies. Two kinds of typical molecular conformations were separately obtained in these crystals through substituent group control or the solvent effect. Importantly, a symmetrical 3,3-conformer exhibits that a planar central benzene ring prefers a 3D-type crystal growth mode, demonstrating high phosphorescence efficiency. Such outcome is attributed to the strong crystal protection effect of the 3D crystal and the bright global minimum (GM) boat-like T-1 state of the symmetrical 3,3-conformer. The conformation studies further reveal small deformation of the inner benzene ring in both singlet and triplet states. The GM boat-like T-1 state is indicated by theoretical calculations, which is far away from the conical intersection (CI) point between the S-0 and T-1 potential energy surfaces. Meanwhile, the small energy gap between S-1 and T-1 states and the considerable spin-orbit coupling matrix elements allow an efficient population of the T-1 state. Combined with the crystal protection and conformation effect, the 3,3- conformer crystal shows high phosphorescence efficiency. The unsymmetrical 2,4-conformer conformation with the twisted central benzene ring leads to 1D or 2D crystal growth mode, which has a weak crystal protection effect. In addition, the unsymmetrical conformation has a dark GM T-1 state that is very close to the T-1-S-0 CI point, implying an efficient nonradiative T-1-S-0 quenching. Thus, weak phosphorescence was observed from the unsymmetrical conformation. This study provides an insight for the development of highly emissive phosphorescent materials.
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| 15. |
- Zhao, Dandan, et al.
(författare)
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Investigation of ion irradiation hardening behaviors of tempered and long-term thermal aged T92 steel
- 2018
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Ingår i: Journal of Nuclear Materials. - : Elsevier BV. - 0022-3115. ; 511, s. 191-199
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Tidskriftsartikel (refereegranskat)abstract
- 9Cr ferritic/martensitic steels are promising materials for in-core components in advanced Gen-IV reactors. In these applications, their long-term microstructural stability under thermal exposure and resistance to neutron irradiation are essential. Tempered (unaged) and long-term thermal aged T92 samples were used to evaluate the effects of thermal aging and ion irradiation on the microstructure and micromechanical properties of the steel. Both the tempered and aged samples were irradiated with 3 MeV Fe11+ions to 0.25, 0.50, 1.00 and 5.00 dpa at room temperature. Using the nanoindentation technique, the irradiation hardening behaviors of T92 steel were investigated. The irradiation hardening effect was observed in both the tempered and aged T92 samples. To eliminate the soft substrate effect, the critical indentation depth was determined using the ratio of the average hardness of irradiated and unirradiated samples at the same depth. Under the same irradiation conditions, the macroscopic hardness values of the aged T92 samples after irradiation were lower than those of the tempered samples. The irradiation hardening effect was more significant in the aged T92 due to the decreased dislocation density and the coarsened martensitic lath after long-term thermal aging.
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| 16. |
- Zhao, Dandan, et al.
(författare)
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Proton irradiation induced defects in T92 steels: An investigation by TEM and positron annihilation spectroscopy
- 2019
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Ingår i: Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 442, s. 59-66
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Tidskriftsartikel (refereegranskat)abstract
- In order to investigate proton irradiation damage on ferritic/martensitic T92 steels, both the unaged and aged (650 °C for 15,000 h) T92 steels were irradiated with 250 keV protons to 0.01, 0.05 and 0.20 dpa at room temperature due to the lower dose rate of protons compared with heavy-ions. The microstructural evolution induced by thermal aging and proton irradiation was studied by transmission electron microscopy and positron annihilation spectroscopy, and the corresponding micromechanical property changes were investigated by nano-indentation. After 0.20 dpa proton irradiation, the dominant irradiation-induced dislocation loops were a0100 type loops for both the unaged and aged samples. The dislocation-type defects in the aged T92 sample were larger in size and higher in number density, compared with those in the unaged samples. Less vacancy-type defects induced by protons were detected in the aged than the unaged T92 samples under the same irradiation conditions. The higher number density of dislocation-type defects led to more severe irradiation hardening in the aged T92 samples.
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| 17. |
- Zhao, Tianyang, et al.
(författare)
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The modality switching costs of Chinese-English bilinguals in the processing of L1 and L2
- 2020
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Ingår i: Quarterly Journal of Experimental Psychology. - : SAGE Publications. - 1747-0218 .- 1747-0226. ; 73:3, s. 396-412
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Tidskriftsartikel (refereegranskat)abstract
- Modality switching cost indicates that people's performance becomes worse when they judge sequential information that is related to different sensory modalities than judging information that is related to the same modality. In this study, we conducted three experiments on proficient and non-proficient bilingual individuals to investigate the modality switching costs in L1 and L2 processing separately. In Experiment 1, materials were L1 and L2 words that were either conceptually related to a visual modality (e.g., light) or related to an auditory modality (e.g., song). The modality switching costs were investigated in a lexical decision task in both L1 and L2. Experiment 2 further explored the modality switching costs while weakening the activation level of the perceptual modality by adding a set of fillers. Experiment 3 used a word-naming task to explore the modality switching effect in language production in L1 and L2. Results of these experiments showed that the modality switching costs appeared in both language comprehension and production in L1 and L2 conditions. The magnitude of the modality switching costs was conditionally modulated by the L2 proficiency level, such as in the L2 condition in Experiment 1 and in both L1 and L2 conditions in Experiment 3. These results suggest that sensorimotor simulation is involved in not only language comprehension but also language production. The sensorimotor simulation that is acquired in L1 can be transferred to L2.
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| 18. |
- Zhu, Liangliang, et al.
(författare)
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Chirality Control for in Situ Preparation of Gold Nanoparticle Superstructures Directed by a Coordinatable Organogelator
- 2013
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 135:24, s. 9174-9180
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Tidskriftsartikel (refereegranskat)abstract
- Imposing chirality into nanoscale superstructures is a major step forward toward systematic understanding and utilization of nanomaterials. In an attempt to achieve tunable chirality during in situ preparation of hybrid nanomaterials, we here report a novel unimolecular strategy of employing a coordinatable organogelator for the realization of chirality control in the formation of gold nanoparticle superstructures. The work takes advantage of thermally reversible sol-gel transition of the chiral dispersion as template, which causes different micelle properties that can influence the coordination ability between the organogelator and Au(III) ions. Followed by a reduction reaction, gold nanoparticle superstructures with P-helicity were prepared from the sol form of the template through a coordination-induced chiral inversion, whereas those with M-helicity were obtained from the gel form with chiral holding. Such superstructures are solvent-stable and the chirality difference between them could be observed in many solvent environments.
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| 19. |
- Zhu, Liangliang, et al.
(författare)
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Unimolecular Photoconversion of Multicolor Luminescence on Hierarchical Self-Assemblies
- 2013
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 135:13, s. 5175-5182
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Tidskriftsartikel (refereegranskat)abstract
- Facile tuning of photophysical properties is highly desirable for boosting the performance and versatility of photoluminescent materials. In an attempt to overcome the challenge of achieving the photoswitching of multicolor luminescence on unimolecular platforms, we here report a novel hierarchical self-assembly of a cyanostilbene-naphthalimide dyad as the realization of phototunable luminescence at the unimolecular level. The work takes advantage of the photoisomerization of the cyanostilbene moiety from the Z form to its E form, which causes a morphological disorder in the molecular self-assembly and gives rise to a dual fluorescent characteristic accompanied by a progressive luminescent color conversion from yellow to green and finally to blue. Such systems with convertible multicolor luminescence might exhibit application potentials for unimolecular selective imaging and labeling, as exemplified by the cell imaging studies presented in this work.
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