Lewis-Base Adducts of Group 11 Metal(I) Compounds. XLII. [Cu4X4L4] 'Cubane' Clusters, L = Hindered N-Base Ligand: Synthesis and Structure of the L = 2-(Diphenylmethyl)pyridine Complexes (X = Cl, Br, I)

1989 ◽  
Vol 42 (1) ◽  
pp. 107 ◽  
Author(s):  
LM Engelhardt ◽  
PC Healy ◽  
JD Kildea ◽  
AH White
Keyword(s):  
Bond Distance ◽  
Lewis Base ◽  
Structure Characterization ◽  
Hydrogen Atoms ◽  
X Ray ◽  
The Core ◽  
C 30 ◽  
The Ideal ◽  
Cubane Clusters

The synthesis and single-crystal X-ray structure characterization of tetrameric cubane clusters of copper(1) halides with the hindered N-base ligand 2-(diphenylmethy1)pyridine are reported. The chloride, bromide and iodide structures are isomorphous , crystallizing in the tetragonal space group 141/a, a ≈ 23, c ≈ 12 � , Z = 4 tetramers, the tetramer having crystallographically imposed 4 symmetry, well removed from the ideal 43m. In terms of each X3CuN fragment of the core, this distortion results in one of the N-Cu-X angles being enlarged by c. 30� with respect to the other two and one Cu-X bond distance shortened. Cu-N is also shorter than is usual in a four-coordinate environment and the cluster can be envisaged as being constructed from four quasi-linear monomers. The distortions may be attributed to interaction between the 6- and 2-α-substituent-hydrogen atoms and the halide atoms of the core. The effect diminishes with increasing halide size and increasing volume of the Cu4X4 core.

Structure Characterization of Sintered CaO-Al2O3-SiO2 Glass-Ceramic Reinforced with Spodumene

2013 ◽  
Vol 834-836 ◽  
pp. 309-314
Author(s):  
Zi Fan Xiao ◽  
Jin Shu Cheng ◽  
Jun Xie
Keyword(s):  
Glass Ceramic ◽  
Energy Dispersive Spectrometry ◽  
Crystal Size ◽  
Bending Strength ◽  
Glass Ceramics ◽  
Structure Characterization ◽  
X Ray Diffraction ◽  
Crystalline Phases ◽  
X Ray

A glass-ceramic belonging to the CaO-Al2O3-SiO2(CAS) system with different composition of spodumene and doping the Li2O with amount between 0~2.5 % (mass fraction) were prepared by onestage heat treatment, under sintering and crystallization temperature at 1120 °C for two hours. In this paper, differential thermal analysis, X-ray diffraction, scanning electron microscopy, energy dispersive spectrometry and bending strength test were employed to investigate the microstructure and properties of all samples. β-wollastonite crystals were identified as the major crystalline phases, and increasing Li2O was found to be benefit for the crystallization and tiny crystalline phases remelting, resulting in the content of major crystalline phases increased first and then decreased with increasing the expense of spodumene. Meanwhile, the crystal size can be positively related with the content of Li2O. The preferable admixed dosage of spodumene can be obtained, besides the strength of glass-ceramics can be more than 90 MPa.

scholarly journals Closing the gap between electron and X-ray crystallography

2015 ◽  
Vol 71 (6) ◽  
pp. 737-739 ◽  
Author(s):  
Enrico Mugnaioli
Keyword(s):  
Electron Diffraction ◽  
Structure Characterization ◽  
Diffraction Tomography ◽  
X Rays ◽  
Electron Crystallography ◽  
X Ray ◽  
X Ray Crystallography ◽  
Closing The Gap ◽  
Refinement Algorithm

The development of a proper refinement algorithm that takes into account dynamical scattering guarantees, for electron crystallography, results approaching X-rays in terms of precision, accuracy and reliability. The combination of such dynamical refinement and electron diffraction tomography establishes a complete pathway for the structure characterization of single sub-micrometric crystals.

Lewis-Base Adducts of Group 11 Metal(I) Compounds. LXIV Syntheses, Spectroscopy and Structures of Some 1 : 4 Adducts of Copper(I) and Silver(I) Perchlorates with Triphenylarsine and Triphenylstibine

1997 ◽  
Vol 50 (6) ◽  
pp. 539 ◽  
Author(s):  
Graham A. Bowmaker ◽  
Effendy ◽  
Robert D. Hart ◽  
John D. Kildea ◽  
Brian W. Skelton ◽  
...  
Keyword(s):  
Room Temperature ◽  
Far Infrared ◽  
Lewis Base ◽  
X Ray ◽  
Cation Disorder ◽  
Structure Determinations ◽  
Consistent Picture ◽  
Far Infrared Spectra

Syntheses and room-temperature single crystal X-ray structure determinations are recorded for adducts [M(EPh3)4] (ClO4), M = Cu, E = As (1), Sb (2); M = Ag, E = As (3), Sb (4), enabling comparison with analogous, previously studied MP4 and MN4 environments. The four complexes so characterized all crystallize in the familiar rhombohedral R-3 array (a ≈ 14·4, c ≈ 52 Å, hexagonal setting) with the metal and chlorine atoms located on crystallographic threefold axes. In these arrays Cu–E (axial, off axis) are 2·493(2), 2·533(1) for (1), and 2·572(1), 2·577(1) Å for (2), the disparity in the two independent M-E distances being diminished relative to those of previously studied phosphorus analogues, perhaps in consequence of increasing E size. In (3) and (4), some cation disorder is evident in respect of the ligand pnictide atom (E); for the major components Ag-E are 2·652(3), 2·680(2) in (3); 2·732(2), 2·7295(8) Å in (4). Problems associated in defining the metal atom environment geometries in the latter are, nevertheless, more satisfactorily overcome in two further determinations of nitrate salts: [Ag(SbPh3)4] (NO3) (5) is of the rhombohedral family with no cation core disorder, Ag–E (axial, off axis) being 2·720(4), 2·725(2) Å, while the structural characterization of a 1 : 4 triphenylarsine adduct of silver nitrate is recorded as its tetraethanol solvate, namely [Ag(AsPh3)4] (NO3).~ 4C2H5OH(6), monoclinic, C2/c, a 18·373(4), b 20·786(5), c 21·070(8) Å, β 108·18(3)°, Z = 4 f.u. The silver atom of the [Ag(AsPh3)4]+cation unusually lies on a crystallographic 2 (rather than a 3 ) axis of the incipiently23 (T) array, with Ag-As 2·649(2), 2·650(2) Å and As-Ag-As ranging from 108·22(4) to 111·41(6)°. The structure determination of a chloroform solvate of (2), denoted (2a), of low precision, is noted, together with the structure of an interesting artefact, isomorphous with the rhombohedral oxoanion array, modelled as [Ag(PPh3)4]2 (SiF6).py (7). Bands in the far-infrared spectra of [M(AsPh3)4] (ClO4) are assigned to v(MAs) vibrations at 119 (M = Cu) and 103 cm¯1 (M = Ag); this produces a more consistent picture of the variation in the wavenumbers of the v(ME) modes in [M(EPh3)4]+ compounds than was available previously.

scholarly journals Synthesis of Silver Nanoparticles Using Muntingia Calabura L. Leaf Extract as Bioreductor and Applied as Glucose Nanosensor

2018 ◽  
Vol 34 (6) ◽  
pp. 3088-3094 ◽  
Author(s):  
Abdul Wahid Wahab ◽  
Abdul Karim ◽  
Nursiah La Nafie ◽  
Nurafni Nurafni ◽  
I. Wayan Sutapa
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Reduction Method ◽  
Measurement Range ◽  
Structure Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Particle Size Analyzer ◽  
Muntingia Calabura

Silver nanoparticles have been synthesized by reduction method using extract of Muntingia calabura L. leaf a bioreductor. The process of silver nanoparticles formation was monitored by UV-Vis method. The results showed that the absorbance values increased according to the increase of reaction time. Maximum absorption of silver nanoparticle was obtained at a wavelength of 41-421 nm. The size of silver nanoparticles was determined using a PSA (Particle Size Analyzer) with a particle size distribution of 97.04 nm. The functional groups compound that contribute in the synthesis was analyzed using Fourier Transform Infrared Spectroscopy (FTIR). Morphology of the silver nanoparticles was observed by an Scanning Electron Microscope instrument and the structure characterization of the compounds were analyzed using X-Ray Diffraction. The glucose nanosensor based on silver nanoparticles have the measurement range of 1 mM - 4 mM with the regretion (R2) is 0,9516, the detection limit of sensor is 3,2595 mM, the sensitivity of sensor is 2,0794 A. mM-1. mM-2.

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