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101.
We prove that every Kirchberg algebra in the UCT class has nuclear dimension 1. We first show that Kirchberg 2-graph algebras with trivial K0 and finite K1 have nuclear dimension 1 by adapting a technique developed by Winter and Zacharias for Cuntz algebras. We then prove that every Kirchberg algebra in the UCT class is a direct limit of 2-graph algebras to obtain our main theorem. 相似文献
102.
103.
“Click” Chemistry Mildly Stabilizes Bifunctional Gold Nanoparticles for Sensing and Catalysis
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Na Li Dr. Pengxiang Zhao Dr. Na Liu María Echeverria Dr. Sergio Moya Dr. Lionel Salmon Dr. Jaime Ruiz Prof. Dr. Didier Astruc 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(27):8363-8369
A large family of bifunctional 1,2,3‐triazole derivatives that contain both a polyethylene glycol (PEG) chain and another functional fragment (e.g., a polymer, dendron, alcohol, carboxylic acid, allyl, fluorescence dye, redox‐robust metal complex, or a β‐cyclodextrin unit) has been synthesized by facile “click” chemistry and mildly coordinated to nanogold particles, thus providing stable water‐soluble gold nanoparticles (AuNPs) in the size range 3.0–11.2 nm with various properties and applications. In particular, the sensing properties of these AuNPs are illustrated through the detection of an analogue of a warfare agent (i.e., sulfur mustard) by means of a fluorescence “turn‐on” assay, and the catalytic activity of the smallest triazole–AuNPs (core of 3.0 nm) is excellent for the reduction of 4‐nitrophenol in water. 相似文献
104.
The π‐Back‐Bonding Modulation and Its Impact in the Electronic Properties of CuII Antineoplastic Compounds: An Experimental and Theoretical Study
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Juan Carlos García‐Ramos Dr. Rodrigo Galindo‐Murillo Araceli Tovar‐Tovar Ana Luisa Alonso‐Saenz Virginia Gómez‐Vidales Dr. Marcos Flores‐Álamo Dr. Luis Ortiz‐Frade Dr. Fernando Cortes‐Guzmán Dr. Rafael Moreno‐Esparza Prof. Antonio Campero Prof. Lena Ruiz‐Azuara 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(42):13730-13741
105.
Phosphatidylcholine‐Coated Iron Oxide Nanomicelles for In Vivo Prolonged Circulation Time with an Antibiofouling Protein Corona
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Hugo Groult Dr. Jesús Ruiz‐Cabello Ana Victoria Lechuga‐Vieco Dr. Jesús Mateo Dr. Marina Benito Izaskun Bilbao Dr. María Paz Martínez‐Alcázar Dr. Juan. Antonio Lopez Dr. Jesús Vázquez Dr. Fernando F. Herranz 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(50):16662-16671
We report the synthesis of micellar phosphatidylcholine‐coated superparamagnetic iron oxide nanoparticles as a new long circulation contrast agents for magnetic resonance imaging. Oleic acid‐coated Fe3O4 nanoparticles were first prepared through thermal degradation and then encapsulated into small clusters with a phosphatidylcholine coating to obtain hydrophilic nanomicelles. A thorough characterization confirmed the chemical nature of the coating and the excellent colloidal stability of these nanomicelles in aqueous media. Magnetization and relaxivity properties proved their suitability as magnetic resonance imaging (MRI) contrast agent and in vitro cell viability data showed low toxicity. Vascular lifetime and elimination kinetics in the liver were assessed by blood relaxometry and by in vivo MRI in rats and compared with “control” particles prepared with a polyethylene glycol derivative. These micellar particles had a lifetime in blood of more than 10 h, much longer than the control nanoparticles (≈2 h), which is remarkable considering that the coating molecule is a small biocompatible zwitterionic phospholipid. The protein corona was characterized after incubation with rat serum at different times by high‐throughput proteomics, showing a higher proportion of bound apolipoproteins and other dysopsonins for the phosphatidylcholine particles. The antibiofouling properties of this corona and its resistance to the adsorption of proteins corroborate the observed enhanced stability and prolonged systemic circulation. 相似文献
106.
Experimental and Theoretical Studies on Arene‐Bridged Metal–Metal‐Bonded Dimolybdenum Complexes
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Dr. Mario Carrasco Natalia Curado Dr. Eleuterio Álvarez Dr. Celia Maya Dr. Riccardo Peloso Prof. Dr. Manuel L. Poveda Dr. Amor Rodríguez Prof. Dr. Eliseo Ruiz Prof. Dr. Santiago Álvarez Prof. Dr. Ernesto Carmona 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(20):6092-6102
The bis(hydride) dimolybdenum complex, [Mo2(H)2{HC(N‐2,6‐iPr2C6H3)2}2(thf)2], 2 , which possesses a quadruply bonded Mo2II core, undergoes light‐induced (365 nm) reductive elimination of H2 and arene coordination in benzene and toluene solutions, with formation of the MoI2 complexes [Mo2{HC(N‐2,6‐iPr2C6H3)2}2(arene)], 3?C6H6 and 3?C6H5Me , respectively. The analogous C6H5OMe, p‐C6H4Me2, C6H5F, and p‐C6H4F2 derivatives have also been prepared by thermal or photochemical methods, which nevertheless employ different Mo2 complex precursors. X‐ray crystallography and solution NMR studies demonstrate that the molecule of the arene bridges the molybdenum atoms of the MoI2 core, coordinating to each in an η2 fashion. In solution, the arene rotates fast on the NMR timescale around the Mo2‐arene axis. For the substituted aromatic hydrocarbons, the NMR data are consistent with the existence of a major rotamer in which the metal atoms are coordinated to the more electron‐rich C?C bonds. 相似文献
107.
Two C3‐Symmetric Dy3III Complexes with Triple Di‐μ‐methoxo‐μ‐phenoxo Bridges,Magnetic Ground State,and Single‐Molecule Magnetic Behavior
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Dr. Mikko M. Hänninen Prof. Dr. Antonio J. Mota Dr. Daniel Aravena Prof. Dr. Eliseo Ruiz Prof. Dr. Reijo Sillanpää Dr. Agustín Camón Dr. Marco Evangelisti Prof. Dr. Enrique Colacio 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(27):8410-8420
Two series of isostructural C3‐symmetric Ln3 complexes Ln3 ? [BPh4] and Ln3 ? 0.33[Ln(NO3)6] (in which LnIII=Gd and Dy) have been prepared from an amino‐bis(phenol) ligand. X‐ray studies reveal that LnIII ions are connected by one μ2‐phenoxo and two μ3‐methoxo bridges, thus leading to a hexagonal bipyramidal Ln3O5 bridging core in which LnIII ions exhibit a biaugmented trigonal‐prismatic geometry. Magnetic susceptibility studies and ab initio complete active space self‐consistent field (CASSCF) calculations indicate that the magnetic coupling between the DyIII ions, which possess a high axial anisotropy in the ground state, is very weakly antiferromagnetic and mainly dipolar in nature. To reduce the electronic repulsion from the coordinating oxygen atom with the shortest Dy?O distance, the local magnetic moments are oriented almost perpendicular to the Dy3 plane, thus leading to a paramagnetic ground state. CASSCF plus restricted active space state interaction (RASSI) calculations also show that the ground and first excited state of the DyIII ions are separated by approximately 150 and 177 cm?1, for Dy3 ? [BPh4] and Dy3 ? 0.33[Dy(NO3)6], respectively. As expected for these large energy gaps, Dy3 ? [BPh4] and Dy3 ? 0.33[Dy(NO3)6] exhibit, under zero direct‐current (dc) field, thermally activated slow relaxation of the magnetization, which overlap with a quantum tunneling relaxation process. Under an applied Hdc field of 1000 Oe, Dy3 ? [BPh4] exhibits two thermally activated processes with Ueff values of 34.7 and 19.5 cm?1, whereas Dy3 ? 0.33[Dy(NO3)6] shows only one activated process with Ueff=19.5 cm?1. 相似文献
108.
Uncatalyzed Hydroamination of Electrophilic Organometallic Alkynes: Fundamental,Theoretical, and Applied Aspects
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Dr. Yanlan Wang Camille Latouche Dr. Amalia Rapakousiou Colin Lopez Prof Isabelle Ledoux‐Rak Dr. Jaime Ruiz Prof. Jean‐Yves Saillard Prof. Didier Astruc 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(26):8076-8088
Simple reactions of the most used functional groups allowing two molecular fragments to link under mild, sustainable conditions are among the crucial tools of molecular chemistry with multiple applications in materials science, nanomedicine, and organic synthesis as already exemplified by peptide synthesis and “click” chemistry. We are concerned with redox organometallic compounds that can potentially be used as biosensors and redox catalysts and report an uncatalyzed reaction between primary and secondary amines with organometallic electrophilic alkynes that is free of side products and fully “green”. A strategy is first proposed to synthesize alkynyl organometallic precursors upon addition of electrophilic aromatic ligands of cationic complexes followed by endo hydride abstraction. Electrophilic alkynylated cyclopentadienyl or arene ligands of Fe, Ru, and Co complexes subsequently react with amines to yield trans‐enamines that are conjugated with the organometallic group. The difference in reactivities of the various complexes is rationalized from the two‐step reaction mechanism that was elucidated through DFT calculations. Applications are illustrated by the facile reaction of ethynylcobalticenium hexafluorophosphate with aminated silica nanoparticles. Spectroscopic, nonlinear‐optical and electrochemical data, as well as DFT and TDDFT calculations, indicate a strong push–pull conjugation in these cobalticenium– and Fe– and Ru–arene–enamine complexes due to planarity or near‐planarity between the organometallic and trans‐enamine groups involving fulvalene iminium and cyclohexadienylidene iminium mesomeric forms. 相似文献
109.
Rui Guo Xin Zhang Tong Li Qianli Li David A. Ruiz Liu Leo Liu Chen-Ho Tung Lingbing Kong 《Chemical science》2022,13(8):2303
A cationic terminal iminoborane [Mes*N B ← IPr2Me2][AlBr4] (3+[AlBr4]−) (Mes* = 2,4,6-tri-tert-butylphenyl and IPr2Me2 = 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene) has been synthesized and characterized. The employment of an aryl group and N-heterocyclic carbene (NHC) ligand enables 3+[AlBr4]− to exhibit both B-centered Lewis acidity and BN multiple bond reactivities, thus allowing for the construction of tri-coordinate boron cations 5+–12+. More importantly, initial reactions involving coordination, addition, and [2 + 3] cycloadditions have been observed for the cationic iminoborane, demonstrating the potential to build numerous organoboron species via several synthetic routes.An NHC-stabilized aryliminoboryl cation exhibits both boron-centered Lewis acidity and multiple bond reactivity and could be utilized as an effective synthon for unusual cationic boron species. 相似文献
110.
Thays de Souza Lima Fábio Ruiz Simões 《International journal of environmental analytical chemistry》2017,97(8):768-782
This study is aimed to develop an electroanalytical methodology using a boron-doped diamond electrode to determine simultaneously and selectively carbendazim (CBZ) and carbaryl (CAR). In previous studies using cyclic voltammetry oxidation, peaks were observed at 1.03 V (CBZ) and 1.44 V (CAR), with characteristics of an irreversible process controlled by diffusion of species, with a supporting electrolyte of BR buffer (0.1 mol L?1) and pH adjusted to 6.0. The differences between the potentials for both pesticides, about 400 mV, indicate the possibility of selective determination of CBZ and CAR. The square-wave voltammetric parameters were optimised. The best separation conditions were pH 6.0, square-wave frequency of 100 s?1, pulse amplitude of 50 mV and scan increment of 2.0 mV. These parameters were used to obtain the calibration curves of CBZ and CAR. An analytical curve was constructed in the range concentration of CBZ of 1.3 mg L?1 to 15.3 mg L?1 and CAR of 1.0 mg L?1 to 11.4 mg L?1, respectively. The limits of detection (LOD) and limits of quantification (LOQ) for CBZ were 0.40 mg L?1 and 1.30 mg L?1, respectively. For CAR, the LOD and LOQ were 0.30 mg L?1 and 1.00 mg L?1, respectively. Sensitivity values were 0.78 and 2.60 µA/mg L?1 for CBZ and CAR, respectively. The electroanalytical method was applied in Mikania glomerata infusions. The recovery values were 106.2% and 116.5% for CBZ and CAR, respectively. The results show that the developed method is suitable for application in medicinal plant samples. 相似文献