Spectroscopic, crystal, and halogen-exchange studies of halogenotrimolybdates(II)

1967 ◽  
Vol 20 (11) ◽  
pp. 2323 ◽  
Author(s):  
Bronswyk W van ◽  
JC Sheldon

Quantitative solid (potassium halide disk) and hydrochloric acid solution adsorption spectra of halogenotrimolybdates(II) indicate that the compounds are of a common structural type, both in solid and solution, but that at least two kinds of chloro- or bromo-molybdate(II) are present. Variation of absorption intensities with hydrochloric acid molarity suggests the equilibrium (Mo3Cl12)6-+Cl- ↔ (Mo3Cl13)7-, and moreover similar intensity changes occur when K6Mo3Cl12 is in KCl. X-ray diffraction powder photographs of K6Mo3Cl12 and AI7Mo3Cl13,H2O (AI = NH4 or Rb) have been indexed on a pseudo-tetragonal unit cell and indicate 15 and 18 molybdenum atoms per unit oell respectively. The values are decisive for trimers (Mo3) if it is assumed that all the compounds have similar structures. Halogen-exchange studies support the (Mo3X13)7- parental structure, having four bridging, and nine terminal and labile, halogeno groups, since (NH4)7Mo3Cl13,H2O rapidly exchanges only nine chlorine atoms in 1M hydrochloric acid.

2018 ◽  
Vol 54 (3) ◽  
pp. 377-384
Author(s):  
J. Piroskova ◽  
J. Trpcevska ◽  
D. Orac ◽  
M. Laubertova ◽  
H. Horvathova ◽  
...  

This article deals with hydrometallurgical treatment with the subsequent precipitation of zinc from hazardous waste Sal- Ammoniac Skimming produced in wet hot-dip galvanizing process. Chemical analysis showed that skimming contained 46.64% Zn. X-ray diffraction analysis identified the Zn(OH)Cl phase (96.36%) and NH4Cl (3.64%) in Sal-Ammoniac Skimming. The skimming was first subjected to leaching in order to extract zinc into the solution containing HCl, followed by precipitation of the zinc. The experiments were performed in a medium of HCl at concentrations of 0.25, 0.5, 1 and 2M. Complete dissolution of zinc was achieved in 0.5M HCl solution, at 40?C, L:S=20, max. 30 min. The apparent activation energy of leaching reaction by hydrochloric acid solution was Ea=5.543 kJ mol-1. Zn precipitation was carried out using Na2CO3 and NaOH. Zinc oxide with a purity of about 99% was obtained directly from the solution of 6M NaOH at a temperature of 60?C ? 80?Cat pH 8.8.


2013 ◽  
Vol 58 (2) ◽  
pp. 204-209 ◽  
Author(s):  
A. I. Orlova ◽  
A. E. Kanunov ◽  
S. G. Samoilov ◽  
A. Yu. Kazakova ◽  
G. N. Kazantsev

2009 ◽  
Vol 79-82 ◽  
pp. 1719-1722
Author(s):  
Zhi Hong Zhang ◽  
Shao Yu Zhang ◽  
Xue Dong Liu

Attapulgite clay(ATP) from Xuyi county of China was purified by a wet method then treated with NaOH and 1.0 mol/L, 2.0 mol/L and 3.0 mol/L solutions of HCl. Transmission electron microscope(TEM) and X-ray diffraction (XRD) were used to characterize treated ATP. Results showed that wet purification could remove most of impurities. Treatment by alkaline and HCl of 1.0 mol/L and 2.0 mol/L could increase purity while treatment of 3.0 mol/L hydrochloric acid could dissolve some element of ATP so much as form SiO2 and destroy fiber structure to clips. Adsorption experiments of Fe3+ and Ni2+ from aqueous solutions were done using original ATP, purified ATP and treated ATP as absorbents. Results showed that Attapulgite could adsorb metal cations in significant amounts. Sodium hydroxide activation had little influence on adsorption capacity. Influences of acid treatments to ATP on adsorption capacity varied on different concentration solutions.


2012 ◽  
Vol 68 (6) ◽  
pp. 602-609 ◽  
Author(s):  
Anatoly A. Udovenko ◽  
Natalia M. Laptash

Five isomorphous d 0 transition metal oxofluoride compounds A 3[M 2O x F11 − x ]·(AF)0.333 (A = K, Rb, NH4; M = Nb, Mo, W; x = 2, 4) have been synthesized from acid fluoride solutions, and their crystal structures have been determined by single-crystal X-ray diffraction. The basic structural building units are dinuclear M 2 X 11 (dimers) formed from NbOF5 or Mo(W)O2F4 octahedra connected by the fluorine bridging atom. In the Nb2O2F9 dimer, the O atoms occupy apical corners. In the M 2O4F7 (M = Mo, W) dimers two O atoms are also apically placed, whereas the other two O atoms are statistically disordered in equatorial planes. The arrangement of dimers is so that the hexagonal tunnels containing `free' fluoride ions are formed. During the irradiation process the orthorhombic structure of K3Nb2O2F9·(KF)0.333 transforms into a pseudo-trigonal one with a = 23.15 Å, which is the [101] diagonal of the orthorhombic unit cell. The other four trigonal crystals are merohedral twins.


2008 ◽  
Vol 2008 ◽  
pp. 1-6 ◽  
Author(s):  
Guido Ennas ◽  
Maria F. Casula ◽  
Sergio Marras ◽  
Gabriele Navarra ◽  
Alessandra Scano ◽  
...  

A nanocomposite with an FeOOH/SiO2ratio equal to 17.7 wt% and the pertinent matrix, obtained by etching away the nanoparticles through reaction with hydrochloric acid, were investigated by XRD, TGA-DTA, heliostereopicnometry, BET, and TEM techniques. The study shows the presence in the nanocomposite of ferrihydrite nanoparticles phase with average dimensions around 4 nm. The FeOOH nanoparticles structure was analyzed by synchrotron X-ray diffraction data using the distribution difference curve method. The porous structure of the matrix resulting by etching away the nanoparticles differs significantly from that of a pureSiO2sample obtained by hydrolysis of TEOS under the same operative conditions followed in the nanocomposite preparation.


Author(s):  
Sunardi Sunardi ◽  
Wiwin Tyas Istikowati ◽  
Norhidayah Norhidayah ◽  
Dahlena Ariyani ◽  
Azlan Kamari

Microcrystalline cellulose is an important derivative of cellulosic material obtained from wood and non-wood sources, and is used for pharmaceutical, food, cosmetics, and other industries. The aim of this study was to determine the effect of various hydrochloric acid concentrations on the characteristics of cellulose microcrystals isolated from terap wood (Artocarpus elasticus). The microcrystalline cellulose was hydrolyzed using hydrochloric acid, at concentrations of 1.5 N, 2.5 N, and 3.5 N for 15 minutes, and within a temperature range of 100-105o C. Thesamples were then analyzed for changes in color and functional groups with Fourier Transform Infrared spectroscopy (FTIR), while crystallinity index was evaluated through X-Ray Diffraction Analysis (X-RDF). The FTIR results showed similarity with commercial products, while X-Ray Diffraction confirms the highest crystallinity index in the 2.5 N of cellulose I (69.395 %) and cellulose II (82.73 %).


1997 ◽  
Vol 62 (8) ◽  
pp. 1239-1253 ◽  
Author(s):  
Jonathan Bould ◽  
Paul Brint ◽  
John D. Kennedy ◽  
Mark Thornton-Pett ◽  
Lawrence Barton ◽  
...  

[6-(CO)-6-H-6,9-(PPh3)2-6P,5C-μ-(2-Ph2PC6H4)-arachno-6-IrB9H11] (1) results from the reaction of [6-H-6-(PPh3)-6P,5C-μ-(2-Ph2PC6H4)-nido-6-IrB9H12] (2) with carbon monoxide in refluxing benzene. It is characterised by NMR spectroscopy and by single-crystal X-ray diffraction analysis. Crystals were triclinic, space group P1, with a = 10.688(2), b = 13.114(3), c = 22.356(5) Å, α = 78.33(2), β = 89.482(10), γ = 70.884(12)°, and Z = 2. The compound is of the little-examined arachno ten-vertex metallaborane structural type. A second compound of this type, [6-(CO)-6-H-6,6-(PMe2Ph)2-9-(PPh3)-arachno-6-IrB9H11] (3), isolated from a reaction system involving [Ir(CO)Cl(PPh3)2], PMe2Ph and the [nido-B9H12]- anion, has also been characterised crystallographically. Crystals were triclinic, space group P1, with a = 10.389(1), b = 10.511(1), c = 19.699(3) Å, α = 75.03(1), β = 85.53(1), γ = 74.88(1)°, and Z = 2.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Nnaemeka Nnaji ◽  
Njemuwa Nwaji ◽  
Tebello Nyokong

Tetrakis[(benzo[d]thiazol-2-yl-thio) phthalocyaninato] gallium(III)chloride (1) and tetrakis[(benzo[d]thiazol-2ylphenoxy) phthalocyaninato] gallium(III)chloride (2) were successfully electrodeposited onto aluminium for corrosion retardation in 1.0 M hydrochloric acid solution. The aim of this study was to compare the corrosion resistance of electrodeposited metallated phthalocyanines. Scanning electron microscopy, X-ray diffraction, electrochemical impedance spectroscopy (EIS), and polarization confirmed the aluminium corrosion inhibition potentials of complexes 1 and 2. EIS and polarization techniques showed that complex 2 performed better than complex 1, with values from EIS measurements of 82% for 1 and 86% for 2 in 1.0 M hydrochloric acid solution. The importance of electrodeposition in industries and a dearth of research on the use of electrodeposited metallated phthalocyanines necessitated this study, and results show that coatings formed by electrodeposition of 1 and 2 onto aluminium reduced its susceptibility to corrosion attack.


Author(s):  
Brigitte H. Krause ◽  
Y. C. Chang ◽  
P. Z. Jiang ◽  
D. J. Lam

Diffraction data on single crystals of low Tc phase of Bi-Sr-Ca-Cu-O superconductor indicated a well developed layer structure, but with structural and chemical disorder within the layers. The lattice constant c and the layer sequence for the pseudo-tetragonal unit cell were determined from x-ray diffraction measurements of the 006 reflections. They were found to be 30.84(2) Å for the undoped compound and the same 30.84(2) Å for the lead doped crystals indicating the low superconducting transition temperature (Tc = 80 K) phase. The c-dimension for single crystals doped with both antimony and lead was 29.02(5) Å. Polycrystalline samples of that compound on the other hand formed the high temperature (Tc = 107 K) modification with c = 36.9(6) Å, determined from electron diffraction. A mixture of phases with different stacking of layers was indicated by splitting of diffraction spots. The direction of c was also less well defined in the lead-antimony doped single crystals than in the other two compounds.


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