Space group determination by EXPO2005

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Surface-initiated growth of copper using isonicotinic acid-functionalized aluminum oxide surfaces

Isonicotinate self-assembled monolayers (SAM) were prepared on alumina surfaces (A) using isonicotinic acid (iNA). These functionalized layers (iNA-A) were used for the seeded growth of copper films (Cu-iNA-A) by hydrazine hydrate-initiated electroless deposition. The films were characterized by scanning electron microscopy (SEM), electron-dispersive X-ray spectroscopy, atomic force microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and advancing contact angle measurements. The films are Cu0 but with surface oxidation, and show a faceted morphology, which is more textured (Rq = 460 ± 90 nm) compared to the SAM (Rq = 2.8 ± 0.5 nm). In contrast, growth of copper films by SnCl2/PdCl2 catalyzed electroless deposition, using formaldehyde (CH2O) as the reducing agent, shows a nodular morphology on top of a relatively smooth surface. No copper films are observed in the absence of the isonicotinate SAM. The binding of Cu2+ to the iNA is proposed to facilitate reduction to Cu0 and create the seed for subsequent growth. The films show good adhesion to the functionalized surface

Structural effects on the emission properties of Pr 3+

International audienceSingle crystals of Ba 2 NaNb 5 O 15 doped with Pr 3+ have been grown from sodium tetraborate flux. Their emission properties have been measured as a function of the doping level under different excitation and temperature conditions. The experimental observations have been accounted for by considering the effects of the crystal structure, of the doping mechanisms and of the interactions between host lattice and doping ions. The proposed conclusions have been verified by means of single crystal X-ray diffraction measurements and the resulting site occupancies of the active ions have been discussed in the light of the synthesis procedure

New triorganotin(IV) complexes of polyfunctional S,N,O-Ligands

The new sodium bis(2-pyridylthio)acetate ligand, Na[(pyS)(2)CHCO2], has been prepared in ethanol solution using 2-mercaptopyridine, dibromoacetic acid and NaOH. New tri-organotin(IV) derivatives containing the anionic bis(2-pyridylthio)acetate have been synthesized from reaction between SnR3Cl (R = Me, Bu-n, Ph and Cy) acceptors and Na[(pyS)(2)CHCO2]. Complexes of the type {[(pyS)(2)CHCO2]SnR3} have been obtained and characterized by elemental analyses, FT-IR, ESI-MS, multinuclear (H-1 and Sn-119) NMR spectral data and X-ray crystallography. Crystallisation of the compound {[(pyS)(2)CHCO2]Sn(CH3)(3)}(n), from chloroform/ diethyl ether solution, yielded the complex {[(pyS)(2)CHCO2]Sn(CH3)(3)}(n)center dot CHCl3, which has been characterized by X-ray crystallography

Synthesis, structural characterization, solution chemistry, and preliminary biological studies of the ruthenium(III) complexes [TzH][trans-RuCl 4(Tz)2] and [TzH][trans-RuCl4(DMSO)(Tz)] ·(DMSO), the thiazole analogues of antitumor ICR and NAMI-A

Two ruthenium(III) complexes bearing the thiazole ligand, namely, thiazolium (bisthiazole) tetrachlororuthenate (I, TzlCR) and thiazolium (thiazole, DMSO) tetrachlororuthenate (II, TzNAMI) were prepared and characterized. The crystal structures of both complexes were solved by X-ray diffraction methods and found to match closely those of the corresponding imidazole complexes. The behavior in aqueous solution of both TzlCR and TzNAMI was analyzed spectroscopically. The time-dependent spectrophotometric profiles resemble closely those of the related ICR and NAMI-A anticancer compounds, respectively. It is observed that replacement of imidazole with thiazole, a less basic ligand, produces a significant decrease of the ligand exchange rates in the case of the NAMI-like compound. The main electrochemical features of these ruthenium(III) thiazole complexes were determined and compared to those of ICR and NAMI-A. Moreover, some preliminary data were obtained on their biological properties. Notably, both complexes exhibit higher reactivity toward serum albumin than toward calf thymus DNA; cytotoxicity is negligible in line with expectations. A more extensive characterization of the pharmacological properties in vivo is presently in progress