New cerium(III) and neodymium(III) complexes as cytotoxic agents

The cerium(III) and neodymium(III) complexes of 5‐aminoorotic acid were synthesized and characterized by means of spectral data (IR, Raman, ¹H NMR and ¹³C NMR) and elemental analysis. Significant differences in the IR spectra of the complexes were observed as compared with the spectrum of the ligand. A comparative analysis of the Raman spectra of the complexes with that of the free 5‐aminoorotic acid allowed a straightforward assignment of the vibrations of the ligand groups involved in coordination. ¹H NMR and ¹³C NMR spectra confirmed the formation of the complexes. The ligand and the complexes were tested for the cytotoxic activities on the chronic myeloid leukemia‐derived K‐562, overexpressing the BCR‐ABL fusion protein, and the non‐Hodgkin lymphoma‐derived DOHH‐2, characterized by a rexpression of the antiapoptotic protein bcl‐2 cell lines. The results obtained indicate that the tested compounds exerted a considerable cytotoxic activity upon the evaluated cell lines in a concentration‐dependent manner, which enabled the construction of dose–response curves and the calculation of the corresponding IC₅₀ values. Cytotoxicity towards tumor cells was determined for a broad concentration range. The inorganic salts exerted a very weak cytotoxic effect on these cells that is in contrast to the lanthanide complexes, which exhibited potent cytotoxic activity towards K‐562 and DOHH‐2 cell lines. Copyright © 2006 John Wiley & Sons, Ltd.     

IR luminescence of neodymium(III) and ytterbium(III) complexes with acylpyrazolones in solutions

Acylpyrazolones (L1–L5) have been synthesized and the conditions of their complexation with neodymium(III) and ytterbium(III) ions in aqueous solutions have been elucidated. The component ratio in the synthesized complexes is Nd(Yb): L = 1: 1. The conditions of excitation and luminescence of the ligands and complexes have been studied. The formation of mixed-ligand complexes upon the introduction of trioctyl- or triphenylphosphine oxide leads to a considerable rise of neodymium and ytterbium. In the presence of 1,10-phenanthroline and bathophenanthroline, competing complexation leads to a 20–70% decrease in luminescence intensity. The introduction of water-miscible organic solvents (30 vol %) decreases the Nd(III) and Yb(III) luminescence intensity by a factor of 9–20.     

Tuning the size and shape of colloidal cerium oxide nanocrystals through lanthanide doping

We present a simple method to gradually tune the size and to induce the shape change of CeO(2) nanoparticles via increasing the content of Yb(3+) doping.     

IR luminescence of neodymium(III) and ytterbium(III) ions in complexes with N-alkyl-substituted 2-aminobenzoic acids

The luminescence of neodymium(III) and ytterbium(III) ions in complexes with N-alkyl-substituted 2-aminobenzoic acids has been studied. The luminescence spectra of the Nd(III) complexes show two bands with maxima at 875 and 904 and 1060 nm, and the spectra of the Yb(III) complexes show one band at 980 nm. The introduction of an additional ligand or some surfactants into the Nd(III) and Yb(III) coordination sphere leads to an increase in the luminescence intensity. A correlation between the luminescence intensity of Nd(III) and Yb(III) 2(N-alkylamino)benzoates and the length of the hydrocarbon radical bound to the nitrogen atom has been studied.     

Synthesis,characterization and cytotoxicity evaluation of new cerium(III), lanthanum(III) and neodymium(III) complexes

Complexes of cerium(III), lanthanum(III) and neodymium(III) with coumarin‐3‐carboxylic acid (HCCA) were synthesized by mixing of equimolar amounts of the respective metal nitrates and coumarin‐3‐carboxylic acid in ethanol. The complexes were characterized and identified by elemental analysis, IR and Raman spectroscopy. DTA and TGA were applied to study the compositions of the compounds. The vibrational study showed bidentate coordination of CCA^? to Ln(III) ions through the carbonyl oxygen and the carboxylic oxygen atoms. The newly synthesized compounds were assayed for cytotoxicity against SKW‐3, HL‐60 and Reh cells. The complexes of cerium(III) and lanthanum(III) showed marginal cytotoxic activity against SKW‐3 and Reh cells as compared with the inorganic salts at concentration 200 µM . The complex of neodymium(III) induced approximately 50% reduction of the survival HL‐60 and SKW‐3 cells at concentration 200 µM . Copyright © 2007 John Wiley & Sons, Ltd.     

Lanthanum(III), cerium(III), praesodymium(III), neodymium(III) and samarium(III) chloride triethyl phosphate complexes

Summary Five new MCl₃ · TEP compounds, where M = Ce, Pr, Nd and Sm, and LaCl₃ 2 TEP have been prepared. The magnetic susceptibility and i.r. spectra of these complexes are discussed.Reprints of this paper are not available.     

Composition-tunable Zn(x)Cd(1-x)Se nanocrystals with high luminescence and stability

High-quality Zn(x)Cd(1-x)Se nanocrystals have been successfully prepared at high temperature by incorporating stoichiometric amounts of Zn and Se into pre-prepared CdSe nanocrystals. With increasing Zn content, a composition-tunable emission across most of the visible spectrum has been demonstrated by a systematic blue-shift in emission wavelength. The photoluminescence (PL) properties for the obtained Zn(x)Cd(1-x)Se nanocrystals (PL efficiency of 70-85%, fwhm = 22-30 nm) are comparable to those for the best reported CdSe-based QDs. In particular, they also have good PL properties in the blue spectral range. Moreover, the alloy nanocrystals can retain their high luminescence (PL efficiency of over 40%) when dispersed in aqueous solutions and maintain a symmetric peak shape and spectral position under rigorous experimental conditions. A rapid alloying process was observed at a temperature higher than "alloying point". The mechanism of the high luminescence efficiency and stability of Zn(x)Cd(1-x)Se nanocrystals is explored.     

Ultraviolet 5H3 and visible 5DJ luminescence of europium(III)co-doped with cerium (III) in hexagonal NaGdF4

The luminescence of NaGdF₄:Ce,Eu has been investigated. After excitation of Ce³⁺ ions at room temperature, energy transfer to the Gd³⁺ions occurs, followed by migration over this sublattice to the Eu³⁺ions, resulting mainly in Eu³⁺ emission. At liquidhelium temperatures mainly Gd³⁺⁶P trap emission is observed. The Eu³⁺ emission in this system is remarkable, because ultraviolet Eu³⁺ emission (⁵H₃-⁷F_J) is observed alongside the normal ⁵D_J emission in the visible region.     

电化学法合成强荧光CdTe量子点

采用电化学方法产生的H2Te为碲源(Te2-),快速合成了水溶性强荧光的CdTe量子点.该方法具有操作简单、安全、快速廉价和可大量制备等优点.合成过程中考察了合成温度,pH值和配体比例对制备CdTe量子点的影响.在最优化的实验条件下,电化学方法合成的巯基丙酸配位的CdTe荧光量子产率可达到55％;通过紫外可见光谱(UV...     

The reaction of neodymium(III) oxide with chromium(III) oxide

The reaction of Nd₂O₃ and Cr₂O₃ in air has been studied in the temperature range 350–950°C. The nature and quantity of products formed was investigated primarily by an analytical scheme developed to permit the determination of the amounts of unreacted Nd₂O₃ and Cr₂O₃ and the amounts of possible products. From 350–600°C the sole product was Nd₂(CrO₄)₃, from 630–840°C the products were Nd₂(CrO₄)₃ and NdCrO₃, and from 880 to 950°C the sole product was NdCrO₃. The variation with temperature of the amounts of products formed at constant reaction time was investigated. The kinetics of the reaction were investigated at the following temperatures, 630, 650, 680, 700, 720 and 760°C. At each temperature, with increasing time the amount of Nd₂(CrO₄)₃ formed increased to a maximum and then decreased whereas the amount of NdCrO₃ formed increased continually. The results together with experiments on the effect of oxygen and argon atmospheres are interpreted as follows. NdCrO₃ is not formed by direct combination of Nd₂O₃ with Cr₂O₃. Instead the reaction of the two oxides produces Nd₂(CrO₄)₃, the thermal decomposition of which then leads to the formation of NdCrO₃. The absence of NdCrO₄ as a reaction product is investigated and discussed as is the absence of NdCrO₃ as a reaction product below 630°C.     

Pentadecatungstate with dinuclear cerium(III) unit: synthesis, crystal structure and properties

A novel pentadecatungstate, [H 6Ce 2(H 2O)Cl(W 5O 18) 3] (7-) ( 1), constructed by a dinuclear cerium unit and 15-member ring WO 6 units was prepared and characterized by single-crystal X-ray diffraction. Polyanion 1 exhibits blue photoluminescence with an emission maximum at 488 nm, which is characteristic of cerium(III) transitions from 5d to (2)F 5/2 states. Furthermore, the study of the electrochemical property investigation of 1 shows two reversible redox peaks ascribing to two-electron processes.     

Concise synthesis of NaTi2(PO4)3 nanocrystals with size and morphology control

NaTi_2 (PO_4)_3 (NTP) nanocrystals with high room-temperature ionic conductivity of 1.1×10~3 S/cm were prepared by a concise solvothermal method at 140 ℃ for 3 h, and the aspect ratios of all the NTP nanocrystals are the closest to 0.7. It implies a moderate size-distribution of NTP nanocrystals obtained at 140 ℃ for 3 h is helpful for increasing packing density, and the packing density is the larger, so its conductivity is the higher. The controllability over size and morphology of the NTP nanocrystals via solvothermal temperature and time were investigated. The results suggest that our method is of great potential in synthesizing NTP nanocrystals with high room-temperature ionic conductivity at low cost.     

Controlled synthesis and luminescence of semiconductor nanorods

A variety of nearly monodisperse semiconductor nanocrystals, such as CdS, ZnS, and ZnS:Mn, with controllable aspect ratios have been successfully prepared through a facile synthetic process. These as-prepared nanocrystals were obtained from the reactions between metal ions and thioacetamide by employing octadecylamine or oleylamine as the surfactants. The effects of reaction temperature and time, ratios of thioacetamide to inorganic precursors, and the reactant content on the size and crystal purity of the nanorods, have been systematically investigated. The optical properties and the formation mechanism of the nanorods have also been discussed. For the next biolabel applications, these hydrophobic nanocrystals have also been transferred into hydrophilic colloidal spheres by means of an emulsion-based bottom-up self-assembly approach.     

Spectrofluorimetric determination of pharmaceutical compounds with the cerium(IV)—cerium(III) system

The compounds to be determined are oxidised by cerium(IV). The concentration of cerium(III) formed is measured spectrofluorimetrically. The method has been used both in solution and, by fluorodensitometry, on t.l.c. plates. Detection limits of some substances are 15 ng ml^-1 for the solution method and 5 ng per spot for the t.l.c. method.     

The separation of berkelium(III) from cerium(III)

Factors affecting the separation of Bk(III) and Ce(III) in liquid-liquid extraction by tertiary and quaternary amines from neutral solutions of Li, Na, NH₄ and K nitrates have been investigated. It has been found that the maximum separation factor is reached in the extraction from NaNO₃ solutions by solutions of methyl-containing alkylammonium nitrates in xylene.