各种形貌的纳米Co3O4的制备及其应用*

本文综述了各种形貌的纳米Co₃O₄的制备及其应用。制备纳米Co₃O₄的方法有很多,包括热分解、水热法、溶剂热法、化学喷雾热分解、化学气相沉积和溶胶-凝胶法。各种形貌的Co₃O₄被制备,如纳米球、纳米立方体、纳米管、纳米棒、纳米片、纳米纤维和介孔结构。Co₃O₄是一种重要的磁性P-型半导体,在锂离子电池、超级电容器、电致变色、磁性材料、气体传感器和催化剂等诸多领域有比较广泛的应用。     

Synthesis of arnebinol,an ansa-type prenylated phenol with effects inhibitory to prostaglandin biosynthesis

Arnebinol, a new ansa-type prenylated phenol, was synthesized in 12 steps from geraniol and p-benzoquinone in 5.1 % overall yield.     

Reactions of co-ordinated ligands: Kinetics and mechanisms in the charge transfer interaction between dichloro or diaquo triethylene tetramine Co(III) and ferrocyanide

The cherry red-coloured solid state product obtained by the reaction ofcis-σ diaquo Co (III) triethylene tetramine with ferrocyanide was examined by thermogravimetric, infrared and M?ssbauer techniques. Its electronic spectrum in aqueous medium was interpreted to consist of charge transfer IT transition at 440 nm and a ligand field transition around 330 nm. The kinetics of formation of this 1:1 product in solution was also studied.     

Elimination of zinc interference in the voltammetric determination of cobalt by using iminodiacetic acid

The voltammetric determination of cobalt carried out by adsorbing cobalt dimethylglyoxime onto a mercury electrode and subsequently measuring the current for the reduction of the adsorbed species is subject to interference by zinc. If this interference is neglected and the determination carried out by standard additions large errors may result. The interference can be eliminated by adding iminodiacetic acid.     

Cytotoxic and radiosensitizing effects of nano-C<Subscript>60 </Subscript>on tumor cells in vitro

There is growing evidence in recent years that the pristine fullerene may be endowed with strong pro-oxidant capacity to biological samples. In this investigation we tested the hypothesis that water-soluble fullerene-C₆₀ (nano-C₆₀) may interact with ionizing radiation enhancing its antiproliferative effects. The two tumor cell lines with different radiosensitivity B16 and SMMU-7721 were treated by a combination of pristine fullerene and ⁶⁰Co γ irradiation. We measured cell survival rates, apoptotic characteristics, reactive oxygen species (ROS) production and alteration of cell diameter with or without γ-irradiation. There was reduced survival with B16 and SMMU-7721 cells exposed to nano-C₆₀, with the inhibitory concentrations reducing the viability by 50% to 65 part per billion (ppb) and 150 ppb respectively. For cells exposed to nano-C₆₀ prior to γ-irradiation, damage to cell membranes and increased numbers of apoptotic cells were detected by morphologic Hoechst-staining analysis and Annexin V/propidium iodide double-staining. In cells exposed to nano-C₆₀, there were increased levels of ROS, as measured by fluorescence detection under laser confocal microscopy. Preincubation with non-toxic pristine C₆₀ before γ-ray caused enlargement of cells with increased diameter. The results show that nano-C₆₀ inhibits the growth of tumor cells at certain concentrations and increases the effects of ⁶⁰Co γ-irradiation, possibly through the elevated production of cellular ROS and the membrane disruption. Data in this study indicates a possible consideration of using C₆₀ as a candidate of sensitization modifier in tumor radiation biology.     

The quasicrystal-crystal interface between icosahedral Al-Pd-Mn and deposited Co: Evidence for the affinity of the quasicrystal structure to the CsCl structure

We have evaporated Co on the pentagonal surface of an icosahedral Al-Pd-Mn quasicrystal kept at room temperature. For submonolayer Co deposits, five AlCo domains are formed exposing their (1 1 0) faces parallel to the surface and rotated by 72° with respect to each other. The orientational relationship between these domains and the substrate is determined by the optimum matching of the average quasicrystal structure and the CsCl structure with a lattice constant of about 2.88 Å. For further deposition, body-centred cubic Co domains grow epitaxially on the AlCo domains.     

Magnetic properties of single crystalline Zn1−xCoxO thin films

We report on the magnetic properties of single crystalline thin films of Zn_1−xCo_xO (x=0.003–0.14) grown by plasma-assisted molecular beam epitaxy. In order to understand the role of intermediate charge carriers in the magnetic properties of this material two types of films were fabricated, with and without Ga-codoping. Magnetic measurements were made between 2 and 300 K in fields up to 5 T with a Quantum Design SQUID magnetometer. We found that all the tested films exhibit paramagnetic behavior following the Curie–Weiss law, χ=C/(T−θ), with negative Curie–Weiss temperatures and that this behavior holds even under strong n-doping. We show that the magnetization data, M(H), in function of the Co content provide additional evidence in favor of the antiferromagnetic Co–Co interaction in this material. We also observe that these data exhibit an ‘easy plane’ magnetic anisotropy for all the studied Co concentrations. Finally, we develop a simple cluster model, in order to describe the magnetic properties of ZnCoO, which is found to be in good agreement with our experiments.     

A cobalt (II) complex based on antipyrine derived schiff base as colorimetric sensor for Fe3+ ion

A novel complex [Co(NO₃)₂(APTY)₂H₂O] (1) is synthesized based on 1,5-dimethyl-2-phenyl-4-{[(1E)-pyridine-4-ylmethylene]amino}-1,2-dihydro-3H-pyrazol-3-one) antipyrine (APTY) and the structure of complex (1) is characterized via PXRD, SEM, FTIR and X-ray single crystal diffraction technique. It is found that the complex (1) has a good response to Fe³⁺ ion with colorimetric yellow change. In addition, we demonstrate that the sensing mechanism of complex (1) could is due to the disruption of complex (1) framework and the formation of complex Fe-APTY. The stability, rapid response and low detection limit enable this complex (1) to be a good Fe³⁺ ion chemical sensor for biological and environmental sensing applications.