Yanxian Jin

Luminescent properties of CdTe quantum dots synthesized using 3-mercaptopropionic acid reduction of tellurium dioxide directly

A facile one-step synthesis of CdTe quantum dots (QDs) in aqueous solution by atmospheric microwave reactor has been developed using 3-mercaptopropionic acid reduction of TeO2 directly. The obtained CdTe QDs were characterized by ultraviolet–visible spectroscopy, fluorescent spectroscopy, X-ray powder diffraction, multifunctional imaging electron spectrometer (XPS), and high-resolution transmission electron microscopy. Green- to red-emitting CdTe QDs with a maximum photoluminescence quantum yield of 56.68% were obtained.

Facile synthesis of Ag@Fe3O4@C-Au core-shell microspheres for surface-enhanced Raman scattering

In this paper, a facile approach has been developed to synthesize the novel multifunctional Ag@Fe3O4@C-Au magnetic core-shell microspheres that display a highly efficient surface-enhanced Raman scattering (SERS) substrate with high stability and reproducibility. The morphology, size, chemical component, and magnetic property of as-prepared composite microspheres were characterized by scanning transmission electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), X-ray photoelectron spectra (XPS), and vibrating sample magnetomerter (VSM), respectively. The enhancement effect on the Raman active was investigated by using rhodamine-b (RdB) as a probe molecule. The result shows that the well-designed Ag@Fe3O4@C-Au core-shell microspheres have uniform sphere size and high magnetization, and the SERS signals of RdB on the Ag@Fe3O4@C-Au microspheres were much stronger than those on both Ag@Fe3O4 and Fe3O4@C-Au microspheres.

Highly efficient and porous TiO2-coated Ag@Fe3O4@C-Au microspheres for degradation of organic pollutants

In this paper, we reported a novel hierarchical porous Ag@Fe3O4@C-Au@TiO2 core@shell microspheres with a highly photocatalytic activity and magnetically separable properties. The synthesis method is included of a Fe3O4 magnetic embedded Ag core (Ag@Fe3O4), an interlayer of carbon modified by PEI to form sufficient amounts of amine functional groups (Ag@Fe3O4@C-PEI), the grafting of Au nanoparticles on the surface of Ag@Fe3O4@C-PEI (Ag@Fe3O4@C-Au), and an ordered porous TiO2 structured shell. As an example of the applications, the photocatalytic activities of the samples were investigated by the reduction of Rhodamine B (RhB) under visible-light irradiation. The results show that the porous Ag@Fe3O4@C-Au@TiO2 core@shell microspheres display higher adsorption and photocatalytic activities compared to the pure porous TiO2 and Ag@Fe3O4@C@TiO2 microspheres, which are attributed to the local surface plasmon resonance (LSPR) by the Ag and Au nanoparticles and the high specific surface area.

Theoretical investigation of the reactions of La atom and La+ cation with carbonyl sulfide

The potential energy surfaces for the La+SCO and La++ SCO reactions have been theoretically investigated by using the DFT (B3LYP/ECP/6-311+G(2d)) level of theory. Both ground and excited state potential energy surfaces (PES) are discussed. The present results show that the reaction mechanism is insertion mechanism both along the C-S and C-O bond activation branches, but the C-S bond activation is much more favorable in energy than the C-O bond activation. The reaction of La atom with SCO was shown to occur preferentially on the ground state (doublet) PES throughout the reaction process, and the experimentally observed species, have been explained according to the mechanisms revealed in this work. While for the reaction between La+ cation with SCO, it involves potential energy curve-crossing which dramatically affects reaction mechanism, and the crossing points (CPs) have been localized by the approach suggested by Yoshizawa et al. Due to the intersystem crossing existing in the reaction process of La+ with SCO, the products SLa+(η2CO) and OLa+(η2CS) may not form. This mechanism is different from that of La + SCO system. All our theoretical results not only support the existing conclusions inferred from early experiment, but also complement the pathway and mechanism for this reaction.

(E)-N′-Benzyl­idene-5-methyl­isoxazole-4-carbohydrazide

The molecule of the title compound, C12H11N3O2, is approximately planar with an r.m.s. deviation of 0.0814 Å from the plane through all the non-H atoms. The dihedral angle formed by the benzene and isoxazole rings is 6.88 (16)°. The molecular conformation is stabilized by an intramolecular C—H⋯N hydrogen bond, forming an S(6) ring, and the molecule displays an E configuration with respect to the C=N double bond. In the crystal structure, intermolecular N—H⋯O hydrogen bonds form centrosymmetric dimers which are further linked by weak C—H⋯N interactions augmented by very weak C—H⋯π contacts, forming layers parallel to (120).

5-Methyl-N′-(3-nitrobenzylidene)isoxazole-4-carbohydrazide

The molecule of the title compound, C12H10N4O4, displays an E configuration about the C=N bond. The dihedral angle between the benzene and isoxazole rings is 1.36 (5)° and the molecular conformation is stabilized by the an intramolecular C—H⋯N hydrogen bond. In the crystal structure, centrosymmetrically related molecules are connected by pairs of N—H⋯O hydrogen bonds into dimers, which are further linked into a three-dimensional network by intermolecular C—H⋯O hydrogen bonds and by π⋯π stacking interactions involving adjacent benzene and isoxazole rings, with a centroid–centroid separation of 3.861 (3) Å.

N'-[(E)-2-Hydroxy-benzyl-idene]-5-methyl-isoxazole-4-carbohydrazide monohydrate.

In the structure of the title compound, C12H11N3O3·H2O, the dihedral angle formed by the benzene and isoxazole rings is 2.03 (8)°. The molecular conformation is stabilized by an intramolecular O—H⋯N hydrogen bond. In the crystal structure, molecules are linked into a three-dimesional network by intermolecular N—H⋯O, O—H⋯N and O—H⋯O hydrogen bonds, and by π–π stacking interactions involving adjacent benzene and isoxazole rings [centroid–centroid separation = 3.663 (2) Å].