scholarly journals Synthesis, Spectroscopic and X-Ray Structural Characterization of [Cd(linpen)]2+, a Model for Metal Complexes of the Chelating Polymer Polyethyleneimine (linpen = Linear Pentaethylenehexamine)

1992 ◽  
Vol 47 (6) ◽  
pp. 829-836 ◽  
Author(s):  
Henry Strasdeit
Keyword(s):  
Metal Ion ◽  
X Ray Diffraction ◽  
Linear Isomer ◽  
X Ray ◽  
Chelating Polymer ◽  
The Mean ◽  
Hexadentate Ligand ◽  
Solid Compounds ◽  
Strong Distortion

The isolation of 3,6,9,12-tetraazatetradecane-1,14-diamine (linear isomer of pentaethylenehexamine, linpen) from a technical polyamine mixture is described. In methanol, linpen acts as a hexadentate ligand towards cadmium(II). The solid compounds [Cd(linpen)](BPh4)2 (1), [Cd(linpen)](BPh4)2•2 DMSO (2) and [Cd(linpen)](BF4)2 (3) have been isolated and characterized by elemental analysis, spectroscopy and X-ray powder diffraction. The 113Cd NMR resonance of 1 is at 351 ppm (0.30 M in DMSO-d6, standard: 0.10 M Cd(ClO4)2 in D2O).2 and 3 have been structurally characterized by single-crystal X-ray diffraction. 2: C 2/c; a = 19.337(1)Å, b = 17.937(1)Å, c = 18.584(1)Å, β = 111.54(1)°; Z = 4, R = 0.034, Rw = 0.033.3: P21/n; a = 8.607(1)Å, b = 14.851(2)Å, c = 15.703(2)Å, ß = 91.21(2)°; Z = 4,R = 0.083, Rw = 0.072. Both compounds contain discrete [Cd(linpen)]2+ complexes. The hexamine wraps around the metal ion in a helical manner. This results in a strong distortion of the coordination polyhedron. The mean Cd-N bond lengths are 2.38Å and 2.37Å for 2 and 3, respectively.Models for MN6 centers in metal-polyethyleneimine (PEI) complexes are derived from the structure of [Cd(linpen)]2+. For example, loops at the MN6 site in molecules of linear PEI are proposed.

Characterization of Ni Nanopowders Produced by Electrical Explosion of Wire Technique

2006 ◽  
Vol 510-511 ◽  
pp. 710-713
Author(s):  
Hwan Tae Kim ◽  
Won Sik Seo ◽  
Dae Hwan Kwon ◽  
Pyuck Pa Choi ◽  
Ji Soon Kim ◽  
...  
Keyword(s):  
Particle Size ◽  
Electrical Explosion ◽  
Nickel Wire ◽  
X Ray Diffraction ◽  
Nitrogen Gas ◽  
Argon Gas ◽  
X Ray ◽  
Nickel Powders ◽  
The Mean

Nanosize nickel powders were successfully produced by electrical explosion of wire (EEW). In EEW, the nickel wire was discharged in a chamber filled with nitrogen or argon gas, and the produced powders were subsequently stabilized by air-passivation at room temperature for 2 h. X-ray diffraction only showed the nickel phase of FCC crystal structure, whereas TEM and XPS analyses showed the formation of a very thin oxide layer of NiO on the surface of particles. Particles were spherical in shape, and the mean particle size calculated by specific surface area was about 100 nm. The particle size decreased with increasing charging voltage and with increasing ambient gas pressure. Argon gas was more effective in producing finer particles than nitrogen gas.

A Molecular Chain of Four CoII Ions Stabilized by a Tris-Pyridyl/Bis-?-Diketonate Ligand

2009 ◽  
Vol 62 (9) ◽  
pp. 1130 ◽  
Author(s):  
Leoní A. Barrios ◽  
David Aguilà ◽  
Olivier Roubeau ◽  
Keith S. Murray ◽  
Guillem Aromí
Keyword(s):  
Exchange Interactions ◽  
Molecular Chain ◽  
Water Molecules ◽  
Spin Orbit Coupling ◽  
Antiferromagnetic Exchange ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bulk Magnetization ◽  
Hexadentate Ligand

The synthesis and characterization of a tris-pyridyl/bis-β-diketone molecule (H2L) is reported. This compound acts as a hexadentate ligand towards CoII to facilitate the assembly of a tetranuclear molecular chain of closely spaced metals with formula [Co4L2(MeOH)8](NO3)4 (1), which exhibits a very flat [Co4L2]4+ platform, as determined by single-crystal X-ray diffraction crystallography. Complex 1 readily exchanges axial methanol ligands with water molecules. The bulk magnetization of the resulting hydrate, 1a, shows that the metals in the [Co4L2]4+ moiety exhibit spin-orbit coupling and antiferromagnetic exchange interactions.

Synthesis and Characterization of Surface Protected Nanocrystalline Particles of Titania

1998 ◽  
Vol 519 ◽  
Author(s):  
E. Scolan ◽  
C. Sanchez
Keyword(s):  
X Ray Diffraction ◽  
Elastic Light Scattering ◽  
Titanium Butoxide ◽  
X Ray ◽  
Toluene Sulfonic Acid ◽  
Nanocrystalline Particles ◽  
Mean Size ◽  
The Mean ◽  
Cp Mas Nmr

AbstractMonodisperse non-aggregated nanoparticles of titania are obtained through hydrolysis at 60°C of titanium butoxide in the presence of acetylacetone and para-toluene sulfonic acid. After drying the resulting xerosols can be dispersed without aggregation in water-alcoholic or alcoholic solutions. The characterizations of the nanoparticles have been carried out by using quasi-elastic light scattering (QELS), 13C 1H in solution and X-ray diffraction, TEM, TG-DTA, 13C CP-MAS NMR in the solid state. The mean size of the anatase oxide core can be adjusted in the I to 5 nanometer range by a careful tuning of the synthetic conditions. The anatase particles are surrounded by acetylacetonato ligands, para-toluene sulfonate based species and water.

scholarly journals Synthesis and spectroscopic characterization of some lanthanide(III) nitrate complexes of 3-[3-carboxyethyl-4,5- dimethylthiophene-2-yl)azo]pent-2,4-dione

2011 ◽  
Vol 76 (2) ◽  
pp. 249-261 ◽  
Author(s):  
Janardhanan Athira ◽  
Yesodharan Sindhu ◽  
Susamma Sujamol ◽  
Kochukittan Mohanan
Keyword(s):  
Elemental Analysis ◽  
Metal Ion ◽  
Spectroscopic Characterization ◽  
Molar Conductance ◽  
Spectral Studies ◽  
Structural Form ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nitrate Complexes

3-[3-Carboxyethyl-4,5-dimethylthiophene-2-yl)azo]pent-2,4-dione was synthesized by coupling diazotized 2-amino-3-carboxyethyl- 4,5-dimethylthiophene with acetylacetone. Based on various spectral studies and elemental analysis, an intramolecularly hydrogen bonded azoenol structural form was assigned for the ligand. This ligand is versatile in forming a series of lanthanide(III) complexes viz, lanthanum(III), cerium(III), praseodymium(III), neodymium(III), samarium(III) and gadolinium(III), which were characterized through various spectral studies, elemental analysis, magnetic susceptibility measurements, molar conductance and thermal analysis. The spectral data revealed that the ligand acted as a neutral tridentate, coordinating to the metal ion through one of the azo nitrogen atoms, the ester carbonyl and the enolic oxygen of the acetylacetone moiety, without deprotonation. Molar conductance values adequately supported their non-electrolytic nature. The ligand and lanthanum(III) complexes were subjected to X-ray diffraction studies. In addition, the lanthanum(III) complex underwent a facile transesterification reaction on refluxing with methanol for a long period. The thermal behavior of the lanthanum(III) complex was also examined.

Preparation and Characterization of Lignin Powder Micronized by a Supercritical Antisolvent (SAS) Process

2011 ◽  
Vol 233-235 ◽  
pp. 1642-1645 ◽  
Author(s):  
Qi Lu ◽  
Yuan Gang Zu ◽  
Lei Yang ◽  
Xiu Hua Zhao ◽  
Wen Jun Liu ◽  
...  
Keyword(s):  
Particle Size ◽  
Optimal Conditions ◽  
Orthogonal Array Design ◽  
X Ray Diffraction ◽  
Array Design ◽  
X Ray ◽  
Mean Particle Size ◽  
Supercritical Antisolvent ◽  
The Mean

Nanoscale lignin was successfully prepared with a supercritical antisolvent (SAS) apparatus using acetone as a solvent and superciritical carbon dioxide as an antisolvent. Four factors were studied and optimized by a four-level orthogonal array design (OAD). According to analysis of variance, precipitation pressure had a significant effect on mean particle size. The optimal conditions are as follows: precipitation temperature 35 °C, precipitation pressure 30 MPa, temperature difference +10 °C and concentration of lignin solution 0.5 mg/mL. The micronized lignin under the optimal conditions was characterized by Scanning Electron Microscopy (SEM), Fourier-transform Infrared Spectroscopy (FTIR), Dynamic Light Scattering (DLS) and X-Ray Diffraction (XRD) analyses. The results showed the mean particle size of micronized lignin was 0.144 ± 0.03 μm and had no degradation. The solubility of micronized lignin was improved significantly in distilled water.

Characterization of Ultra Fine Palladium Particles with the Mean Size of 20 A by X-Ray Diffraction

1981 ◽  
Vol 50 (9) ◽  
pp. 3071-3074 ◽  
Author(s):  
Ken-ichi Ohshima ◽  
Shigeki Yatsuya ◽  
Jimpei Harada
Keyword(s):  
X Ray Diffraction ◽  
X Ray ◽  
Mean Size ◽  
The Mean ◽  
Palladium Particles

A convenient and selective route to a trans-difunctionalized macrocyclic hexadentate N4O2 ligand

2001 ◽  
Vol 79 (7) ◽  
pp. 1105-1109 ◽  
Author(s):  
Hongyan Luo ◽  
Robin D Rogers ◽  
Martin W Brechbiel
Keyword(s):  
Functional Groups ◽  
Metal Ion ◽  
Condensation Reaction ◽  
Synthesis And Characterization ◽  
Tetraaza Macrocycle ◽  
X Ray ◽  
Hexadentate Ligand

The synthesis and characterization of a novel difunctionalized tetraaza macrocycle, 1,8-bis(2-hydroxybenzyl)-1,4,8,11-tetraazacyclotetradecane (abbreviated H2bcyclamb), is described. The diprotic hexadentate ligand N4O2 was conveniently synthesized in two steps by the cyclic condensation reaction of 1,4,8,11-tetraazacyclotetradecane (abbreviated cyclam) and salicylaldehyde, followed by NaBH4 reduction of the cyclic hexahydropyrimidine condensate. The difunctionalization was selective and is the first procedure of trans-difunctionalization of a tetraazamacrocycle, without generating mono-, tri-, or tetra-functionalized products, with only 1,8-difunctionalized product being isolated, and with the convenience of the functionalization occurring as a result of deprotection. The trans-arrangement of the two functional groups in H2bcyclamb was verified by X-ray crystallographic studies of the copper(II) complex [Cu(H2bcyclamb)](OAc)2·2H2O. The crystal is monoclinic, P21/c, with a = 10.0931(2), b = 13.8820(1), c = 10.8752(1) Å, β = 106.332(1)°, V = 1462.26(3) Å3. The structure of [Cu(H2bcyclamb)](OAc)2·2H2O also shows the metal ion in an elongated octahedral geometry.Key words: 1,8-difunctionalized, cyclam, copper(II) complex.

Preparation and Characterization of Nitrogen-Doped TiO2 Decorated with Different Metal Ion

2012 ◽  
Vol 486 ◽  
pp. 368-372
Author(s):  
Hui Zhao ◽  
Yan Wang
Keyword(s):  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Metal Ion ◽  
Photocatalytic Oxidation ◽  
X Ray Diffraction ◽  
One Pot ◽  
X Ray ◽  
Photocatalytic Activities ◽  
Diffuse Reflectance Spectrometry

In this paper, nanotubular TiO2 obtained by hydrothermal method was selected as precursor to prepare metal ion decorated TiO2-xNxvia a facile and one-pot method. As-synthesized M/TiO2-xNx (M references to Pd, Fe, Ni, Li) photocatalysts were characterized by means of X-ray diffraction, diffuse reflectance spectrometry, fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The photocatalytic activities of different metal ion decorated TiO2-xNx samples were compared by monitoring the photocatalytic oxidation of propylene under both ultraviolet light (UV) and visible light (Vis) irradiation. It was found that Pd/TiO2-xNx sample possessed the highest photocatalytic activity under both UV and Vis irradiation. The better crystallinity, better visible light absorption, higher hydroxy concentration were contributed to the best photocatalytic performance of Pd/TiO2-xNx.

scholarly journals SYNTHESIS AND CHARACTERIZATION OF SOME HYDRAZINEDERIVATIVES WITH Α, Β UNSATURATED ACIDS

2015 ◽  
Vol 2 (2) ◽  
pp. 16-22
Author(s):  
Manimekalai R ◽  
Kalpanadevi K ◽  
Anjutha Prabha N ◽  
Raina O
Keyword(s):  
Metal Ion ◽  
Nickel Complexes ◽  
Synthesis And Characterization ◽  
Metal Carboxylate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns ◽  
Dta Studies ◽  
Cobalt And Nickel

Metal cinnamate monohydrazinates of the formula M(cin)2N2H4, where M= Co or Zn, nickel crotante monohydrazinate monohydrate Ni(crot)2N2H4.H2O, metal cinnamate and crotonate dihydrazinates M(cin)2(N2H4)2 Where M = Co, Ni, Zn or Cd , M(crot)2(N2H4)2 Where M = Co or Ni and cadmium crotante dihydrazinate monohydrate Cd(crot)2(N2H4)2.H2O have been prepared and characterized by spectral, thermal and X-ray diffraction studies. Electronic spectra indicate that the cobalt and nickel complexes are high-spin octahedral complexes. The IR data show that the binding of hydrazine and the unsaturated carboxylate anion to the metal ion is bidentate. TG-DTA studies show that metal complexes undergo decomposition through metal carboxylate intermediate to give respective metal oxide as the final product. Xray powder diffraction patterns of the complexes indicate isomorphism among them.

scholarly journals Characterization of Radium Sulphate

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Hanna Hedström ◽  
Ingmar Persson ◽  
Gunnar Skarnemark ◽  
Christian Ekberg
Keyword(s):  
Substitutional Solid Solution ◽  
Barium Sulphate ◽  
X Ray Diffraction ◽  
Lead Sulphate ◽  
X Ray ◽  
Cell Parameters ◽  
Barium Strontium ◽  
The Mean ◽  
Sulphate Media

This paper examines the crystal structure of radium sulphate and compares its structure to barium sulphate, strontium sulphate, and lead sulphate. The radium sulphate powder was measured by both powder X-ray diffraction and EXAFS. The unit cell was determined to be orthorhombic, belonging to the Pnma (no. 62) space group with the cell parameters a=9.07 Å, b=5.52 Å, c=7.28 Å, and V=364.48 Å3. These data support the fact that radium sulphate is isostructural with barium, strontium, and lead sulphate. The bond distances were determined using EXAFS. The mean Ra–O and S–O bond distances were found to be 2.96(2) Å and 1.485(8) Å, respectively, and the Ra–O–S bond angle was 127(2)∘. Findings of EXAFS data are quite consistent and support the XRD data. These findings show that it is possible for radium to coprecipitate with barium, strontium, and lead in sulphate media to form a substitutional solid solution.

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