Realizing high-rate and high-capacity features of Lihium-organic batteries is essential for their practical use but remains a big challenge, which is due to the instrinsic poor conductivity, limited redox kinetics and low utility of organic electrode mateials. This work presents a well-designed donor-acceptor Covalent Organic Framework (COFs) with extended conjugation, mesoscale porosity, and dual redox-active centers to promote fast charge transfer and multi-electron processes. As anticipated, the prepared cathode with benzo [1,2-b:3,4-b':5,6-b''] trithiophene (BTT) as p-type and pyrene-4,5,9,10-tetraone (PTO) as n-type material (BTT-PTO-COF) delivers impressive specific capacity (218 mAh g at 0.
View Article and Find Full Text PDFAqueous zinc-ion batteries (AZIBs) are one of the most compelling alternatives of lithium-ion batteries due to their inherent safety and economics viability. In response to the growing demand for green and sustainable energy storage solutions, organic electrodes with the scalability from inexpensive starting materials and potential for biodegradation after use have become a prominent choice for AZIBs. Despite gratifying progresses of organic molecules with electrochemical performance in AZIBs, the research is still in infancy and hampered by certain issues due to the underlying complex electrochemistry.
View Article and Find Full Text PDFRationally designed organic redox-active materials have attracted numerous interests due to their excellent electrochemical performance and reasonable sustainability. However, they often suffer from poor cycling stability, intrinsic low operating potential, and poor rate performance. Herein, a novel Donor-Acceptor (D-A) bipolar polymer with n-type pyrene-4,5,9,10-tetraone unit storing Li cations and p-type carbazole unit which attracts anions and provides polymerization sites is employed as a cathode for lithium-ion batteries through in situ electropolymerization.
View Article and Find Full Text PDFThe upconversion luminescence (UCL) in the second near-infrared window (NIR-II) is highly attractive due to its excellent performance in high-resolution bioimaging, anticounterfeiting, and temperature sensing. However, upconvertion nanoparticles (UCNPs) are normally emitted in visible light, potentially impacting the imaging quality. Here, a monochromatic Er-rich (NaErF:x%Yb@NaYF) nanoparticles with excitation at 1532 nm and emission at 978 nm is proposed, both situated in the NIR-II region.
View Article and Find Full Text PDFDual-ion batteries based on organic electrodes show great potential to break through the bottlenecks existed in conventional LIBs due to their high specific capacity, lifted working voltage, and environmental benignity. Herein, two innovative viologen-based bipolar copolymers poly(viologen-pyrene-4,5,9,10-tetrone dichloride) (PVPTOCl ) and poly(viologen-anthraquinone dichloride) (PVAQCl ) were synthesized and applied as high performance cathodes for lithium-dual-ion battery. Bearing the dual-ion storage capability of viologen and carbonyls, as well as the conjugated structure of pyrene-4,5,9,10-tetrone, the synthesized copolymers show remarkable electrochemical performances for LIBs.
View Article and Find Full Text PDFOrganic lanthanide complexes have garnered significant attention in various fields due to their intriguing energy transfer mechanism, enabling the upconversion (UC) of two or more low-energy photons into high-energy photons. In comparison to lanthanide-doped inorganic nanoparticles, organic UC complexes hold great promise for biological delivery applications due to their advantageous properties of controllable size and composition. This review aims to provide a summary of the fundamental concept and recent developments of organic lanthanide-based UC materials based on different mechanisms.
View Article and Find Full Text PDFAlkynes are widely used in chemistry, medicine and materials science. Here we demonstrate a transition-metal and photocatalyst-free inverse Sonogashira coupling reaction between iodoalkynes and (hetero)arenes or alkenes under visible-light irradiation. Mechanistic and computational studies suggest that iodoalkynes can be directly activated by visible light irradiation, and an excited state iodoalkyne acted as an "alkynyl radical synthetic equivalent", reacting with a series of C(sp)-H bonds for coupling products.
View Article and Find Full Text PDFSearching new organic cathode materials to address the issues of poor cycle stability and low capacity in lithium ion batteries (LIBs) is very important and highly desirable. In this research, a 2D boroxine-linked chemically-active pyrene-4,5,9,10-tetraone (PTO) covalent organic framework (2D PPTODB COFs) was synthesized as an organic cathode material with remarkable electrochemical properties, including high electrochemical activity (four redox electrons), safe oxidation potential window (between 2.3 and 3.
View Article and Find Full Text PDFA novel conjugated copolymer has been synthesized and employed as an organic cathode material in rechargeable lithium-ion batteries (LIBs). Due to the synergistic effects from conducting aniline and pyrene units, the resultant batteries based on the as-obtained copolymer can deliver a promising reversible specific capacity of 113 mAh g with a high voltage output of 3.2 V and a remarkable 75.
View Article and Find Full Text PDFPolymers (Basel)
January 2019
Organic thermoelectric (TE) materials can directly convert heat to electricity, and they are emerging as new materials for energy harvesting and cooling technologies. The performance of TE materials mainly depends on the properties of materials, including the Seebeck coefficient, electrical conductivity, thermal conductivity, and thermal stability. Traditional TE materials are mostly based on low-bandgap inorganic compounds, such as bismuth chalcogenide, lead telluride, and tin selenide, while organic materials as promising TE materials are attracting more and more attention because of their intrinsic advantages, including cost-effectiveness, easy processing, low density, low thermal conductivity, and high flexibility.
View Article and Find Full Text PDFHerein, two new quadrupolar acceptor-π-donor-π-acceptor (A-π-D-π-A) chromophores have been prepared featuring a strongly electron-donating diborene core and strongly electron-accepting dimesitylboryl (BMes ) and bis(2,4,6-tris(trifluoromethyl)phenyl)boryl (B Mes ) end groups. Analysis of the compounds by NMR spectroscopy, X-ray crystallography, cyclic voltammetry, and UV/Vis-NIR absorption and emission spectroscopy indicated that the compounds have extended conjugated π-systems spanning their B C cores. The combination of exceptionally potent π-donor (diborene) and π-acceptor (diarylboryl) groups, both based on trigonal boron, leads to very small HOMO-LUMO gaps, resulting in strong absorption in the near-IR region with maxima in THF at 840 and 1092 nm and very high extinction coefficients of ca.
View Article and Find Full Text PDFFracture healing is a repair process of a mechanical discontinuity loss of force transmission, and pathological mobility of bone. Increasing evidence suggests that microRNA (miRNA) could regulate chondrocyte, osteoblast, and osteoclast differentiation and function, indicating miRNA as key regulators of bone formation, resorption, remodeling, and repair. Hence, during this study, we established a right femur fracture mouse model to explore the effect microRNA-185 (miR-185) has on osteoblasts in mice during fracture healing and its underlying mechanism.
View Article and Find Full Text PDFObjective: To investigate results of total knee arthroplasty using the long-stem tibial component combined with metallic wedge of knee prosthesis for the treatment of proximal defects.
Methods: From January 2011 to May 2013, 10 patients (11 knees) were treated with total knee arthroplasties using the long-stem tibial component with metallic tibial wedge of knee prosthesis. All the patients were female and the average age was 67 years old (ranged, 60 to 77 years old).
Monometallic and dimetallic complexes with the ruthenium-amine conjugated structural unit have been prepared. These complexes display consecutive redox waves with low potentials and rich and intense absorptions in the near-infrared region. The electrochemical and spectroscopic properties can be modulated using substituents or auxiliary ligands with different electronic natures.
View Article and Find Full Text PDFThe construction of well-controlled porous materials is very challenging. Herein, we report the successful preparation of structurally defined porous membranes based on hexakistriphenylamine metallacycles through electropolymerization. The newly designed porous materials were characterized by the typical cyclic voltammograms, XPS, SEM, and TEM investigations.
View Article and Find Full Text PDFFive osmium complexes with redox-active amine substituents, [Os(ttpy)(Ntpy)](PF6)2 (1(PF6)2), [Os(Ntpy)2](PF6)2 (2(PF6)2), [Os(ttpy)(NPhtpy)](PF6)2 (3(PF6)2), [Os(Ntpy)(NPhtpy)](PF6)2 (4(PF6)2), and [Os(NPhtpy)2](PF6)2 (5(PF6)2), have been prepared, where ttpy is 4'-tolyl-2,2':6',2″-terpyridine, Ntpy is 4'-(di-p-anisylamino)-2,2':6',2″-terpyridine, and NPhtpy is 4'-(di-p-anisylaminophen-4-yl)-2,2':6',2″-terpyridine. X-ray crystallographic data of 2(PF6)2 and 4(PF6)2 are presented. These complexes show rich visible absorptions attributed to the singlet metal-to-ligand charge-transfer ((1)MLCT), triplet MLCT, and intraligand charge-transfer transitions.
View Article and Find Full Text PDFJ Huazhong Univ Sci Technolog Med Sci
August 2015
The neuroprotective effects of escitalopram oxalate in rats with chronic hypoperfusion and the possible mechanism were explored. Chronic hypoperfusion (2-VO) model was prepared and given escitalopram oxalate (experimental group) or PBS (control group) after 6 weeks. Eight weeks after the operation, Morris water maze test was carried out to evaluate the learning and memory ability of the rats.
View Article and Find Full Text PDFCyclometalated diruthenium complexes 1(PF6)2-5(PF6)2 bridged by 1,3,6,8-tetra(pyrid-2-yl)-pyrene have been prepared, with the terminal ligand bis(N-methylbenzimidazolyl)pyridine (1(PF6)2), 4'-di-(p-methoxyphenyl)amino-2,2':6',2″-terpyridine (2(PF6)2), 4'-p-methoxyphenyl-2,2':6',2″-terpyridine (3(PF6)2), 2,2':6',2″-terpyridine (4(PF6)2), and trimethyl-4,4',4″-tricarboxylate-2,2':6',2″-terpyridine (5(PF6)2). The single-crystal X-ray structure of 4(PF6)2 is presented. These complexes show two stepwise anodic redox pairs, and the potentials progressively increase from 1(PF6)2 to 5(PF6)2.
View Article and Find Full Text PDFAryl chalcones rearrange and add methanol to give substituted propane-1-ones upon UV-A irradiation in the presence of PPh3. We propose two possible mechanisms for this photo-rearrangement. The reaction involves either the formation of a phosphine-carbonyl intermediate, nucleophilic addition of MeOH and 1,2-aryl migration or the formation of ylide and carbene intermediates.
View Article and Find Full Text PDFNine cyclometalated ruthenium complexes with a redox-active diphenylamine unit in the para position to the RuC bond were prepared. MeO, Me, and Cl substituents on the diphenylamine unit and three types of auxiliary ligands-bis(N-methylbenzimidazolyl)pyridine (Mebip), 2,2':6',2''-terpyridine (tpy), and trimethyl-4,4',4''-tricarboxylate-2,2':6',2''-terpyridine (Me3 tctpy)--were used to vary the electronic properties of these complexes. The derivative with an MeO-substituted amine unit and Me3 tctpy ligand was studied by single-crystal X-ray analysis.
View Article and Find Full Text PDFMonoamine 1, diamines 2-4, triamine 5, and tetraamine 6 have been synthesized by substituting dianisylamino groups at the 1-, 3-, 6-, and/or 8-positions of pyrene. Diamines 2-4 differ in the positions of the amine substituents. No pyrene-pyrene interactions are evident in the single-crystal packing of 3, 4, and 6.
View Article and Find Full Text PDFOrganic-inorganic mixed-valence systems with strongly-coupled triarylamine and cyclometalated osmium have been developed. They display two well-separated redox couples at low potentials. Each of the three readily accessible oxidation states can be distinguished by the absorbance at three different wavelengths.
View Article and Find Full Text PDFFour bis-tridentate ruthenium complexes with 5,5′′-divinyl-4′-tolyl-2,2′:6′,2′′-terpyridine (dvtpy) have been synthesized. Among them, 3(PF6) ([(dvtpy)Ru(Mebib)](PF6)) and 4(PF6) ([(dvtpy)Ru(dpb)](PF6)) are cyclometalated, and 5(PF6)2 ([(dvtpy)Ru(Mebip)](PF6)2) and 6(PF6)2 ([(dvtpy)Ru(tpy)](PF6)2) are noncyclometalated, where Mebib is 2-deprotonated-1,3-bis(N-methylbenzimidazolyl)benzene, dpb is 2-deprotonated-1,3-di(2-pyridyl)benzene, Mebip is 2,6-bis(N-methylbenzimidazolyl)pyridine, and tpy is 2,2′:6′,2′′-terpyridine, respectively. Reductive electropolymerization of these complexes and copolymerization of 4(PF6) and 5(PF6)2 proceeded smoothly, both on glassy carbon and ITO glass electrodes, to afford stable metallopolymeric films with well-defined redox processes.
View Article and Find Full Text PDFOxidative electropolymerization of cyclometalated bisruthenium complexes [(Nptpy)2Ru2(tppyr)](PF6)2 and [(Nptpy)2Ru2(tpb)](PF6)2 produced adherent metallopolymeric films on electrode surfaces, where Nptpy is 4'-(p-N,N-diphenylamino)phenyl-2,2':6',2″-terpyridine, tppyr is the 2,7-bisdeprotonated form of 1,3,6,8-tetra(pyrid-2-yl)pyrene, and tpb is the 3,6-bisdeprotonated form of 1,2,4,5-tetra(pyrid-2-yl)benzene. The resulting polymers are composed of two types of alternating constituent units: tppyr- or tpb-bridged cyclometalated bisruthenium units and biphenyl-bridged bis-triarylamine segments. These films exhibited four well-defined anodic redox couples as a result of the stepwise oxidations of these two units.
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