Wu Jinguang

Solvent Extraction of Au(I) from Auro‐Cyanide Solution with Cetyltrimethylammonium Bromide/Tri‐n‐Butyl Phosphate System using Column‐Shaped Extraction Equipment

Abstract Solvent extraction of Au(I) from alkaline cyanide solution containing several milligram per liter of gold was investigated with column‐shaped extraction equipment using tri‐n‐butylphosphate (TBP) as extractant with addition of quaternary ammonium salt, cetyltrimethylammonium bromide (CTAB), directly into the aurous aqueous phase in advance. The influences of the volume of TBP and the NaCl concentration in the aurous aqueous phase on Au(I) extraction were investigated. The experimental results for treating 50 L of synthetic auro‐cyanide solution containing 10 mg/L Au(I) and for treating real auro‐cyanide leaching liquor by CTAB/TBP system were reported. The results obtained establish that the column‐shaped extraction equipment was suitable for extracting Au(I) from low content auro‐cyanide solution at high aqueous/organic phase ratio, and that more than 97% of gold(I) could be extracted while the Au(I) concentration in the raffinate was less than 0.3 mg/L. In addition, the stripping of Au(I) from the loaded organic phase and the recycle of the organic phase were also discussed.

Synthesis and characterization of a ytterbium complex with diphenylacetylpyrazolone Yb(DPAP)3•(H2O)2•3EtOH

Abstract Reaction of YbCl 3 with NH 4 DPAP (HDPAP= 1,3-diphenyl-4-acetylpyrazol-5-one) in a 1:3 molar ratio results in the formation of the complex Yb(DPAP) 3 ·(H 2 O) 2 ·3EtOH, the crystal structure of which has been determined. The compound crystallizes in the monoclinic system, space group P 2 1 / n with Z = 4, unit cell parameters a = 16.067(2), b =22.254(3), c = 15.297(2) A and β= 99.46(3)°. The structure has been refined to R = 0.0501 (R w = 0.057) for 7201 indepedent reflections. The coordination polyhedron about the eight- coordinate ytterbium atom is a square antiprism. The three DPAP ligands are bidentate to the central metal ion, where two water molecules are also coordinated. The average bonding distances are YbO (DPAP) = 2.31(1) A, YbO (water) = 2.36(1) A. The complex has been further characterized by elemental analysis, TGA, DTA and IR spectroscopy.

FT-IR Study And Intensity Calculation On The Hydration Of Acetonitrile

During recent years, the FT-IR study on hydration of molecules attracted considerable interests. The peak positions and intensities of IR bands of some molecules change apparently after hydration. The theoretical explanation to these changes, especially to the intensity variation, is rather few. In this investigation, the effect of hydration on the IR intensity of acetonitrile has been systematically studied. Three parts are included: 1. Experiments: CH3CN-CC14-H20 systems were prepared from acetonitrile, tetrachloromethane and water. The volume percents of acetonitrile kept 80% in all solutions and the volumes of water in these solutions were 0.0, 3.0, 6.0, 9.0, 12.0 and 15.0% respectively. The infrared spectra of these solutions were measured quantitatively by Nicolet 7199B FT-IR spectrometer. It was found that the intensity of C-N stretching band(2200 cm-1) became stronger when water was added and the more the water was added, the larger the intensity increase was. This is caused by the formation of hydrogen bond between CH3CN and H20. 2. Normal coordinate analysis: The normal analysis of CH3CN was carried out. It was found that the IR spectrum of liquid acetonitrile could not be explained by the model of C3v symmetry of acetonitrile molecule. This effect on the IR bands is now under investigation. 3. The infrared intensity calculation: The atomic polar tensors (APT s) of CH3CN and CH3CN--H20 were calculated. The APIs of CH3CN were quite different from those of CH3CN--H20. The infrared intensities of C-N stretching bands in CH3CN and CH3CN--H20 were calculated respectively. The increase of IR intensity of C--N stretching band when water was added has been explained to some extent.

On the Tributylphosphate-Based Super-Concentrated HCl System

We reported a new super-concentrated hydrochloric acid system prepared by using tri-n-butyl phosphate (TBP)-constructed reversed micelles at ambient temperature and pressure. According to the titration result, the molar ratio of H+ to H2O (denoted as n(H)+/nH(2)O) in the super-concentrated HCl range from 0. 50 to 1. 50 which are higher than that in saturated aqueous HCl bulk solution (0. 28). Significant a moment of hydrochloric acid is confined in W/O reversed micelles. Therefore, the behavior and status of HCl are different from those of conventional bluk solution. FTIR spectroscopic results demonstrate that a significant amount of HCl remains in the molecular form rather than being ionized into H+ and Cl-. Thus, super-concentrated HCl provides an extraordinary chemical environment which may have significant influence on certain substances. We found that the color of the solution is reddish brown when copper ion is dissolved in super-concentrated HCl, while the color of the saturated HCl aqueous solution (37 Wt%) containing copper ion is green. That is to say, the copper ions exist in a special state under the unique chemical environment of super-concentrated HCl. UV-Vis-NIR spectra indicate that both d-d transition band and charge transfer transition band of copper ions in super-concentrated HCl solution underwent significant variations. In addition, copper ions also have obvious influence on the hydrogen bond network among HCl in the super-concentrated HCl solution. Remarkable variation is introduced in the H-Cl stretching band in FTIR spectra.

Enhanced brightness of Eu3+ complex in organic electroluminescent devices by using another rare-earth ion

Rare-earth ions Tb3+ and La3+ were used as a bridge to improve the energy transfer from the polymer to an Eu complex. The material Tb(La)0.5Eu0.5(BSA)3phen was synthesized and used as the emission layer in the device: ITO/PVK:Tb(La)0.5Eu0.5(BSA)3phen/Alq/Al. The two device were compared in detail and it was found that the device using La0.5Eu0.5(BSA)3phen as the emission material had better monochromatic characteristics with the maximal brightness of 102 cd/m2 and the colour coordinates x = 0.55 and y = 0.36.

Conformational Change During Modification Of Creatine Kinase By Iodoacetamide: A Resolution Enhanced FT-IR Analysis

FTIR and Raman spectra, resolution enhanced by second derivative and deconvolution techniques, have been used for studying protein secondary structure 1,2. A subtle conformational changes related to solvent denaturation and chemical modification can be distinguished. It has been shown that Raman spectroscopy combined with second derivative techniques and hydrogen-deuterium isotopic exchange can be successfully applied to identify he subtle comformational differences in creative kinase(EC 2.7.3.2)3.

FT-IR Spectra Of The C=O And C-H Stretching Vibration Of Lauric Acid

FT-IR spectra of lauric acid in different media were examined. In very dilute solution of lauric acid in CC14, the two bands at 1711 and 1760 cm-1 the region 1650 to 1800 cm-1 were observed for the C=0 stretching modes of dimer and monomer of lauric acid, respectively. In n-butanol KBr pellet and fluorinated hydrocarbon media, the three bands at 1712, 1701 and 1687 cm-1 after deconvolution and curve analysis for the C=0 stretching mode can be observed. In the region of C-H stretching vibration, the wavenumber shifts of the CH2 symmetric and antisymmetric stretching bands of lauric acid in different media show that the packings of acyl chains of lauric acid in different media are not the same.

The Fourier Transform Infrared Spectra Of Liquid Water

Taking the advantage of the high resolving power and sensitivity of the FTIR spectrometer and using multiple scanning technique, we have successfully resolved the stretching vibrational band of liquid water near 3400 cm-1 into 8 peaks of rotational fine structure and determined the molar absorptivities of various vibrational modes.

Fourier Transform Infrared Study On The Hydration Of Polyadenylic Acid(Poly A). I. Static Hydration Properties

By means of FT-IR and subtraction techniques the absorption spectra of Poly A film have been studied systematically in the 4000 to 800 cm-1 region at 25 0C as a function of relative humidities (from 0% to 100%) approached by static equilibrium. According to the frequency and intensity changes of infrared spectra it proves that the hydration of Poly A has happened mainly on the -NH2 group of base, -P02 group and ribose ring. The largest frequency shift is observed on the -NH2 band and the strongest variation in intensity is on the -NH2 band, ribose-phosphate main chain vibration and -P02 symmetric stretching vibration. The spectra of water molecule also vary obviously and split into multiple peaks during hydration.