Search results for " Crystal structure"
showing 10 items of 129 documents
Dopamine interaction with a polyamine cryptand of 1H-pyrazole in the absence and in the presence of Cu(II) ions. Crystal structure of [Cu2(H21L](ClO4…
2000
The crystal structure of the binuclear Cu2+ complex [Cu2(H21L)](ClO4)3·2H2O of the cryptand L = 1,4,7,8,11,14,17,20,21,24,29,32,33,36-tetradecaazapentacyclo[12.12.12.1^(6,9).1^(19,22),1,^31,34]hentetraconta-6,9(41),19(40), 21,31,34(39)-hexaene is presented; evidence for the formation in solution of binary L–dopamine and ternary Cu2+–L– dopamine complexes is presented. Escarti Alemany, Francisco, Francisco.Escarti@uv.es ; Garcia-España Monsonis, Enrique, Enrique.Garcia-Es@uv.es ; Latorre Saborit, Julio, Julio.Latorre@uv.es
Triorganotin(IV) derivatives of 7-amino-2-(methylthio)[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylic acid. Synthesis, spectroscopic characterization, …
2010
Triorganotin(IV) complexes of the 7-amino-2-(methylthio)[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylic acid (HL), Me 3 SnL(H 2 O), ( 1 ), [ n -Bu 3 SnL] 2 (H 2 O), ( 2 ), Ph 3 SnL(MeOH), ( 3 ), were synthesized by reacting the amino acid with organotin(IV) hydroxides or oxides in refluxing methanol. The complexes have been characterized by elemental analysis, 1 H, 13 C and 119 Sn NMR, IR, Raman and 119 Sn Mossbauer spectroscopic techniques. Single crystal X-ray diffraction data were obtained for compounds ( 2 ) and ( 3 ). Ph 3 SnL(MeOH) presents a trigonal bipyramidal structure with the organic groups on the equatorial plane and the axial positions occupied by a ligand molecule, coordinated …
Luminescence, vibrational and XANES studies of AlN nanomaterials
2007
Abstract The paper reports comparative studies on synthesized aluminium nitride nanotubes, nanoparticles and commercially available micron-sized AlN powder using different spectroscopic techniques: cathodoluminescence measurements (CL), X-ray absorption near edge spectroscopy (XANES) and Fourier-transform infrared spectroscopy (FTIR). Crucial distinctions in CL spectra are observed for nano- and microsized aluminium nitride powders; systematic shift of the IR absorption maximum has been detected for nanostructured aluminium nitride as compared to commercial samples. Through XANES experiments on Al K-edge structural differences between nano- and bulk AlN are revealed, intensity of features i…
Ex situ investigations of MOCVD-grown gallium nitride nanowires using reflection high energy electron diffraction
2011
Vertically oriented nanowires (NWs) of single-crystalline wurtzite GaN have been fabricated on sapphire substrates, via metal organic chemical vapor deposition (MOCVD). We present ex situ investigations on orientation and structure of grown GaN nanowires on GaN(0001) surface using reflection high energy electron diffraction (RHEED). Both ordered and randomly oriented GaN crystalline structures have been detected.
Isolation of Four New CoII/CoIII and NiII Complexes with a Pentadentate Schiff Base Ligand: Syntheses, Structural Descriptions and Magnetic Studies
2011
In this paper we report the temperature and pH dependent syntheses and systematic characterization of four new Co(II)/Co(III) and Ni(II) complexes with a pentadentate Schiff base ligand H(3)L obtained by condensing 1,3,-diaminopropan-2-ol with 2-hydroxyacetophenone in 1:2 molar ratio. The room temperature syntheses involving Co(II) and Ni(II) nitrates and the ligand H(3)L lead to the isolation of the dinuclear species [Co(2)L(2)(H(2)O)] (1), and the mononuclear complex [Ni(LH)] (3), respectively, whereas refluxing at basic pH leads to the tetranuclear complexes, [Co(II)(2)Co(III)(2)L(2)(μ(3)-OMe)(2)(NO(3))(H(2)O)(2)]NO(3)·2(H(2)O) (2), and [Ni(4)L(2)(μ(3)-OMe)(2)(H(2)O)(2)]·2H(2)O (4). 1 is…
(S)-2-[(2-Hydroxybenzyl)azaniumyl]-4-(methylsulfanyl)butanoate
2011
The zwitterionic title compound, C12H17NO3S, is a reduced Schiff base derived from (S)-N-(2-hydroxybenzylidene)methionine. An intramolecular interaction between the N—H and carboxylate groups forms a roughly planar (r.m.s. deviation = 0.1405 Å) five-membered ring containing the H(N), N, Cα, C(carboxylate) and O atoms in a pentagonal conformation. In the crystal, a supramolecular triangle-shaped motif is generated by molecules held together by O—H...O and N—H...O hydrogen bonds.
Characterization of single semiconductor nanowires by synchrotron radiation nanoprobe
2012
In this work, we report on the results of the characterization of single semiconductor nanowires by x-ray fluorescence nanoprobe. Wurtzite InGaN and Co-implanted ZnO single nanowires were studied. Ternary semiconductor nanowires show an axial inhomogeneous elemental distribution, with Ga accumulating at the bottom and In at the top of the wires. The ZnO NWs, on the other hand, show a homogeneous distribution of the Co implanted along the nanowires, without signatures of clustering or segregation effects induced by the implantation. No signatures of unintentional doping are observed neither in the InGaN nor the ZnO NWs. These overall results demonstrate the suitability of X-ray fluorescence …
Synthesis and crystal structure of [(PhenH)(PhenH2)][BiCl6] . 2H2O with different o-phenanthroline protonations.
1998
The reaction between bismuthate oxide and phen (1,10-phenanthroline) in acid medium led to the isolation of the unusual [(PhenH)(PhenH2)][BiCl6] 2H2O derivative, which has been characterized by X-ray analysis and IR spectroscopy. The compound crystallizes in the triclinic space group P1 with a = 8.313(2), b = 9.349(2), c = 9.807(3) A, a = 86.39(3), B = 110.27(3) and y = 106.48(3)°. The crystal structure is made of [BiCl6] 3- anions and [(PhenHXPhenr2)]3+cations. A network of hydrogen bond interactions involving the two clathrated water molecules, the phenanthroline moiety and the chlorines characterizes the entire structure.
Synthesis and chemical characterization of CuII, NiII and ZnII complexes of 3,5-bis(20-pyridyl)-1,2,4-oxadiazole and 3-(20-pyridyl)5-(phenyl)-1,2,4-o…
2011
The synthesis and structural characterization of NiII, CuII and ZnII complexes of two chelating 1,2, 4-oxadiazole ligands, namely 3,5-bis(20-pyridyl)-1,2,4-oxadiazole (bipyOXA) and 3-(20-pyridyl)5- (phenyl)-1,2,4-oxadiazole (pyOXA), is here reported. The formed hexacoordinated metal complexes are [M(bipyOXA)2(H2O)2](ClO4)2 and [M(pyOXA)2(ClO4)2], respectively (M = Ni, Cu, Zn). X-ray crystallography, 1H and 13C NMR spectroscopy and C, N, H elemental analysis data concord in attributing them an octahedral coordination geometry. The two coordinated pyOXA ligands assume a trans coplanar disposition, while the two bipyOXA ligands are not. The latter result is a possible consequence of the format…
1,8-Bis[3-(triethoxysilyl)propyl]-1,8-diazoniatricyclo[9.3.1.14,8]hexadecane diiodide
2009
The organic molecule of title compound, C30H66N4O6Si22+·2I−, is located around a centre of symmetry. The structure exhibits disorder of the triethoxy groups with the ratios 0.78 (1)/0.22 (1), 0.67 (1)/0.33 (1) and 0.58 (1)/0.42 (1).