SOME FERRIC HALIDE COMPLEXES, AND TERNARY COMPLEXES WITH THIOCYANATE IONS

1955 ◽  
Vol 33 (10) ◽  
pp. 1603-1613 ◽  
Author(s):  
M. W. Lister ◽  
D. E. Rivington
Keyword(s):  
Ionic Strength ◽  
Constant Temperature ◽  
Ferric Chloride ◽  
Equilibrium Constants ◽  
Spectrophotometric Study ◽  
Ternary Complexes ◽  
Extinction Coefficients ◽  
Halide Complexes ◽  
High Chloride ◽  
Chloride Concentrations

A spectrophotometric study of solutions containing ferric and bromide ions; ferric, bromide, and thiocyanate ions; and ferric, chloride, and thiocyanate ions is reported. The measurements were made at constant temperature and ionic strength. The data were interpreted with the help of the results from the first paper of this series. The data show that FeBr++ and FeBr2+ are formed, and values are obtained for the equilibrium constants for their formation from simple ions, and for the extinction coefficients of FeBr++. When thiocyanate is also present, the data can best be interpreted by assuming that FeSCNBr+ or FeSCNCl+ is formed. At high chloride concentrations it seems necessary to postulate also FeCl2+ and FeSCN•Cl2. Estimates are made for the equilibrium constants for the formation of all these species from simple ions. As with the corresponding sulphate complexes, there seems to be no particular reluctance to form mixed complexes such as FeSCNCl+, as compared with the 'simple' complexes such as FeCl2+.

FERRIC SULPHATE COMPLEXES, AND TERNARY COMPLEXES WITH THIOCYANATE IONS

1955 ◽  
Vol 33 (10) ◽  
pp. 1591-1602 ◽  
Author(s):  
M. W. Lister ◽  
D. E. Rivington
Keyword(s):  
Ionic Strength ◽  
Constant Temperature ◽  
Equilibrium Constants ◽  
Spectrophotometric Study ◽  
Ternary Complexes ◽  
Ferric Sulphate ◽  
Extinction Coefficients ◽  
Mixed Complexes

A spectrophotometric study of solutions containing ferric and sulphate ions, and also ferric, sulphate, and thiocyanate ions, is reported. The measurements were made at constant temperature and ionic strength; the effect of varying acidity was also investigated. The data were interpreted with the help of the results of the first paper of this series. It is believed that the data show that FeSO4+ and FeHSO4++ ions are formed. Values are obtained for the equilibrium constants for their formation from simple ions, and for their extinction coefficients. At higher sulphate concentrations there is evidence for the appearance of Fe(SO4)2− and FeSO4•HSO4, and estimates are made of their equilibrium constants. When thiocyanate is also present, the data can best be interpreted by assuming that the complex FeSO4•SCN is formed, and at higher sulphate probably also Fe(SO4)2SCN−−. Values are obtained for the equilibrium constants for the formation of these species, and the results would indicate that mixed complexes of this type are formed as readily as 'simple' ones such as Fe(SO4)2−.

SOME MEASUREMENTS ON THE IRON (111)–THIOCYANATE SYSTEM IN AQUEOUS SOLUTION

1955 ◽  
Vol 33 (10) ◽  
pp. 1572-1590 ◽  
Author(s):  
M. W. Lister ◽  
D. E. Rivington
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Equilibrium Constant ◽  
Equilibrium Constants ◽  
Spectrophotometric Study ◽  
Concentrated Solutions ◽  
Extinction Coefficients ◽  
Ferric Thiocyanate ◽  
Different Temperatures

A spectrophotometric study of the ferric thiocyanate system is reported. The temperature and ionic strength of the solutions were carefully controlled, and suitable precautions were taken against fading. From the data, values of the equilibrium constant for the formation of FeSCN++ from simple ions, and of the extinction coefficients of FeSCN++ were obtained for different temperatures and ionic strengths, with results that differed somewhat from earlier values. The effect of varying acidity was also investigated. From more concentrated solutions, values for the equilibrium constants for the formation of Fe(SCN)2+ and Fe(SCN)3 were obtained; it was not necessary to postulate higher complexes.

Spectrophotometric study of reaction of sodium 6-hydroxy-5-dibenzo(a,j)phenoxazone-11,13-disulfonate with aluminium ions in the presence of cationoid tensides

1980 ◽  
Vol 45 (4) ◽  
pp. 1227-1235
Author(s):  
Nguyen Truong Son ◽  
Jan Lasovský ◽  
Eduard Ružička
Keyword(s):  
Acidic Medium ◽  
Equilibrium Constants ◽  
Ternary Systems ◽  
Photometric Determination ◽  
Spectrophotometric Study ◽  
Ternary Complexes ◽  
Medium Ph ◽  
Binary And Ternary Systems

In weakly acidic medium, pH 3.5-6.5, the title dye forms with aluminium ions a complex with the Al : L ratio 1 : 1. In the presence of cetylpyridinium or carbethoxypentadecyltrimethylammonium, ternary complexes AlL3Sr (r = 6 or 9, respectively) are formed. The equilibrium constants of the complexing equilibria in the binary and ternary systems concerned were calculated, and a method of photometric determination of aluminium has been suggested.

Spectrophotometric study of the reaction of dyes of the alizarin green series with indium(III) ions in the presence of cationic tensides

1980 ◽  
Vol 45 (3) ◽  
pp. 703-714 ◽  
Author(s):  
Nguyen Truong Son ◽  
Eduard Ružička
Keyword(s):  
Equilibrium Constants ◽  
Ternary Systems ◽  
Spectrophotometric Study ◽  
Ternary Complexes ◽  
Conditional Stability ◽  
Acid Media ◽  
Weakly Acid ◽  
Cetyl Pyridinium ◽  
Conditional Stability Constants

The reactions of four dyes of the alizarin green series with indium(III) ions were studied. In weakly acid media of pH 4-6.5, binary InL and InL2 complexes are formed in solution. In the presence of cationic tensides containing cetyltrimethylammonium and cetyl pyridinium, defined ternary complexes, InL3S6, are formed in the solution. The conditional stability constants of the binary In-L complexes and the equilibrium constants of the studied complexing ternary systems were calculated and a procedure for the photometric and chelometric determination of indium was proposed.

scholarly journals Spectrophotometric study of time stability and acid-base characteristics of chelerythrine and dihydrochelerythrine

2010 ◽  
Vol 8 (3) ◽  
pp. 626-632 ◽  
Author(s):  
Helena Absolínová ◽  
Luděk Jančář ◽  
Irena Jančářová ◽  
Jaroslav Vičar ◽  
Vlastimil Kubáň
Keyword(s):  
Ionic Strength ◽  
Spectral Properties ◽  
Equilibrium Constants ◽  
Ionic Species ◽  
Spectrophotometric Study ◽  
Time Stability ◽  
Priority Effect ◽  
Acid Base ◽  
Strength Of Interaction ◽  
Transition Reaction

AbstractTime stability, acid-base and UV-VIS spectral properties of dihydrochelerythrine (DHCHE) were studied spectrophotometrically in water:methanol and water:ethanol media. DHCHE is stable in strongly acid milieu (pH HCl, HNO3, H2SO4, H3PO4 and their mixtures. Remarkable shifts of formation parts of absorbance-pH (A-pH) curves to the alkaline medium were observed depending on the type and concentration of inert electrolyte (most remarkable for HNO3 and HCl). The corresponding equilibrium constants pKR+ of the transition reaction between charged iminium Q+ and uncharged QOH (pseudo-base, 6-hydroxy-dihydro derivative) forms of chelerythine were calculated using a numerical interpretation of A-pH curves by a SQUAD-G computer program which ranged from 8.51–9.31. The highest changes of ΔpK R+ (0.75 and 0.53) were observed for H3PO4 and H2SO4, respectively. The priority effect of ionic species and ionic strength was confirmed in the presence of additions of NaCl and KCl. The strength of interaction of CHE with biomacromolecular compounds (i.e., peptides, proteins, nucleic acids etc.) may be affected because of the observed influence of both cation and anion of the inert electrolyte on acid-base behavior.

Spectrophotometric study of the complexation equilibria of cadmium ions with 5-bromo and 5-chloro derivatives of 2-(2-pyridylazo)-5-diethylaminophenol (BrPADAP, ClPADAP)

1983 ◽  
Vol 48 (1) ◽  
pp. 52-59 ◽  
Author(s):  
Vlastimil Kubáň ◽  
Miroslav Macka
Keyword(s):  
Equilibrium Constants ◽  
Spectrophotometric Study ◽  
Graphical Analysis ◽  
Optimal Conditions ◽  
Cadmium Ions ◽  
Brij 35 ◽  
Ethanol Medium ◽  
Triton X ◽  
Derivatives Of

The composition, optical characteristics, molar absorption coefficients and equilibrium constants of the reactions of formation of the ML and ML2 complexes of both reagents with cadmium(II) ions were determined by graphical analysis and numerical interpretation of the absorbance-pH curves by the modified SQUAD-G program. Optimal conditions were proposed for the spectrophotometric determination of Cd in 10% v/v ethanol medium in the presence of 0.1% w/v Triton X-100 or 1% w/v Brij 35. BrPADAP and ClPADAP are the most sensitive spectrophotometric reagents for the determination of cadmium(II) ions (ε = 1.28-1.44 . 105 mmol-1 cm2 at 560 nm and pH 8.0-9.5) with a high colour contrast in the reaction (Δλmax ~117 nm) and a selectivity similar to that of other N-heterocyclic azodyes (PAR, PAN, etc.).

Spectrophotometric study of the reactions of lanthanoids with bromopyrogallol red in the presence of cation active tensides

1982 ◽  
Vol 47 (2) ◽  
pp. 503-508 ◽  
Author(s):  
Irena Němcová ◽  
Pavla Plocková ◽  
Tran Hong Con
Keyword(s):  
Absorption Spectra ◽  
Photometric Determination ◽  
Spectrophotometric Study ◽  
Ternary Complexes ◽  
Optimal Conditions ◽  
Bromopyrogallol Red ◽  
Binary Complexes

The absorption spectra of the binary complexes of lanthanoids with bromopyrogallol red were measured and the formation of ternary complexes with cation active tenside, Septonex, was studied. Optimal conditions were found for the formation of these complexes and the possibility of their use in the photometric determination of lanthanoids was demonstrated on several examples.

Spectrophotometric study of the acid-base and optical properties of the 5-bromo and 5-chloro derivatives of 2-(2-pyridylazo)-5-(diethylamino)phenol (BrPADAP, ClPADAP) and their complexation equilibria with zinc(II) ions

1982 ◽  
Vol 47 (10) ◽  
pp. 2676-2691 ◽  
Author(s):  
Miroslav Macka ◽  
Vlastimil Kubáň
Keyword(s):  
Equilibrium Constants ◽  
Spectrophotometric Study ◽  
Graphical Analysis ◽  
Alkaline Media ◽  
Acid Base ◽  
Ethanol Medium ◽  
Triton X ◽  
Mixed Water ◽  
Derivatives Of

The optical and acid-base characteristics of BrPADAP and ClPADAP were studied in mixed water-ethanol and water-DMF media and in 10% ethanol medium in the presence of cationic, anionic and nonionic tensides. The composition, optical characteristics, molar absorption coefficients and equilibrium constants of the ML and ML2 complexes with zinc(II) ions were found by graphical analysis and numerical interpretation of the absorbance curves by the modified SQUAD-G program. Optimal conditions were found for the spectrophotometric determination of Zn(II) in the presence of 0.1% Triton X-100 or 1% Brij 35 in alkaline media with pH = 6.5-10. BrPADAP and ClPADAP are the most sensitive reagents (ε = 1.3-1.6 . 105 mmol-1 cm2 at 557 and 560 nm, respectively) for the determination of zinc with high colour contrast of the reaction (Δλ = 104 nm) and selectivity similar to that for the other N-heterocyclic azodyes (PAN, PAR, etc.).

Column Study on the Effect of Nitrate and Chloride on TCE Removal by Granular Iron

2011 ◽  
Vol 356-360 ◽  
pp. 1642-1646
Author(s):  
Xue Qiang Zhu ◽  
Bao Ping Han ◽  
Guo Jun Wu ◽  
Xiao Qing Zhang
Keyword(s):  
Pitting Corrosion ◽  
Nitrate Concentration ◽  
Chloride Concentration ◽  
Inorganic Anions ◽  
Dual Effect ◽  
Column Study ◽  
Granular Iron ◽  
High Chloride ◽  
Chloride Concentrations

The effects of individual inorganic anions (nitrate and chloride) on the reactivity of granular iron were investigated using plexiglass columns packed with granular iron. The results show that TCE removal decreases apparently with increasing nitrate concentration due to competition for reactive sites. Chloride exhibits dual-effect on the TCE removal by Fe0. In the studied condition, the TCE dechlorination is enhanced at the low chloride concentration due to pitting corrosion and is dampened at the high chloride concentrations such as 59.98 and 110.45 mg/L as Cl-.

Sign in / Sign up

Export Citation Format

Share Document