Kinetics of the Reaction of Chromium(VI) with Tris(1,10-phenanthroline)iron(II) Ions in Acidic Solutions. Anion and Medium Effects:  Perchlorate versus Triflate

2006 ◽  
Vol 45 (3) ◽  
pp. 1053-1058 ◽  
Author(s):  
Guodong Du ◽  
James H. Espenson
Keyword(s):  
Medium Effects ◽  
Acidic Solutions ◽  
Chromium Vi ◽  
Kinetics Of

Kinetics of aquation of tris(methylmalonato)chromate(III) anion in acidic solutions

1972 ◽  
Vol 34 (1) ◽  
pp. 221-226 ◽  
Author(s):  
James C. Chang
Keyword(s):  
Acidic Solutions ◽  
Kinetics Of

scholarly journals KINETICS OF ABSORPTION OF NITRIC OXIDE IN AQUEOUS ACIDIC SOLUTIONS OF FERROUS SULFATE

1977 ◽  
Vol 10 (2) ◽  
pp. 120-124 ◽  
Author(s):  
HARUO HIKITA ◽  
SATORU ASAI ◽  
HARUO ISHIKAWA ◽  
SHIGEYUKI HIRANO
Keyword(s):  
Nitric Oxide ◽  
Ferrous Sulfate ◽  
Acidic Solutions ◽  
Kinetics Of

Kinetics of the oxidation of hypophosphorous and phosphorous acids by chromium(VI)

1973 ◽  
Vol 35 (3) ◽  
pp. 901-908 ◽  
Author(s):  
Kalyan K. Sengupta ◽  
J.K. Chakladar ◽  
A.K. Chatterjee
Keyword(s):  
Chromium Vi ◽  
Kinetics Of

Chromium(VI) Species and Spectra in Acidic Solutions

1964 ◽  
Vol 3 (12) ◽  
pp. 1804-1805 ◽  
Author(s):  
James Yingpeh Tong
Keyword(s):  
Acidic Solutions ◽  
Chromium Vi

Solvent Extraction of Chromium(VI) with Tri-n-butyl Phosphate from Aqueous Acidic Solutions

2007 ◽  
Vol 52 (6) ◽  
pp. 2220-2223 ◽  
Author(s):  
Weidong Zhang ◽  
Junteng Liu ◽  
Zhongqi Ren ◽  
Changshun Du ◽  
Jingnan Ma
Keyword(s):  
Solvent Extraction ◽  
Acidic Solutions ◽  
Chromium Vi

scholarly journals SOLVATION OF THE [Cr(NCS)4(IMIDAZOLE)2] ION IN ETHANOL-WATER MIXTURES

2002 ◽  
Vol 10 (11) ◽  
pp. 63-72
Author(s):  
lon Ganescu ◽  
George Bratulescu ◽  
Ion Papa ◽  
Anca Ganescu ◽  
Alin Barbu ◽  
...  
Keyword(s):  
Kinetic Parameters ◽  
Order Reaction ◽  
Water Molecules ◽  
Hydrogen Ions ◽  
Second Order Reaction ◽  
Acidic Solutions ◽  
The Third ◽  
Competitive Reactions ◽  
Different Temperatures ◽  
Kinetics Of

Salvation kinetics of [Cr(NCS)4(imidazole)2]- has been studied in ethanol-water mixtures at different temperatures. The first stage of the solvation consists of two competitive reactions: two NCS- ions are exchanged, presumably, by water molecules and simultaneously an imidazole molecule by ethanol, the latter in a second-order reaction, accelerated by hydrogen ions. The exchange of the amine is followed by the substitution of the first two NCS- ions. The third and fourth NCS- ions are substituted only in neutral and slightly acidic solutions. Kinetic parameters have been determined for reactions (1), (2), and (4). The influence of the solvent composition and acidity is discussed

scholarly journals Compounds of 6, 13-Diamino-6, 13-Dimethyl-1, 4, 8, 11 - Tetraazacyclotetradecane

2021 ◽  
Author(s):  
◽  
Asokamali Siriwardena
Keyword(s):  
Rate Constants ◽  
Magnetic Measurements ◽  
Order Rate Constant ◽  
Acidic Solutions ◽  
First Order ◽  
Order Rate ◽  
Pendant Arm ◽  
Nickel Copper ◽  
13C Nuclear Magnetic Resonance ◽  
Kinetics Of

<p>The reaction of bis-(diaminoethane)nickel(II) chloride, ([Ni(en)2]Cl2 in methanol with formaldehyde and nitroethane in the presence of triethylamine proceeds readily to produce (6, 13-dimethyl-6, 13-dinitro-1, 4, 8, 11-tetraazacyclotetradecane)nickel(II) chloride, [Ni(dini)] - Cl2. Reduction of the nitro groups of this compound by catalytic hydrogenation yields three isomers of the pendant arm macrocyclic complex (6, 13-diamino-6, 13-dimethyl-1, 4, 8, 11-tetraazachyclotetradecane)nickel(II) chloride, designated a-, b- and c-[Ni(diam)]Cl2. These were separated by fractional crystallization. The aisomer was observed to isomerizes slowly in solution to the b- form. A parallel dissociation reaction of the a- isomer was also observed. The demetallation of a- and b- isomers of the diam complex of nickel by reaction with cyanide or concentrated acid at 140 degrees C produces the macrocycle meso-(6, 13-diamino-6, 13-dimethyl-1, 4, 8, 11-tetraazacyclotetra-decane), diam. A variety of hexamine, pentamine and tetramine complexes of diam with nickel(II), copper(II), cobalt(II) and (III), chromium(III), palladium(II), rhodium(III), zinc(II) and cadmium(II) were prepared. Hexamine and tetramine forms of labile metal complexes could be rapidly and reversibly interconverted by altering the pH. The hexamine cobalt(III) cation, [Co(diam)]3+ was by far the most inert of the prepared cobalt(III) complexes, remaining unaffected in hot acidic solutions. In contrast, a single pendant arm of the hexamine [Cr(diam)]3+ cation could be dissociated in acid. (Two possibly triamine complexes of lead were also prepared). These compounds were characterized by elemental analysis, magnetic measurements, electronic, infrared, 1H and 13C nuclear magnetic resonance spectra. The pendant arm protonation constants (log K) of diam and selected complexes of nickel, copper and palladium were calculated from potentiometric titration measurements at 25 degrees C. The log K values for diam at 25 degrees C (I = 0.1 M NaclO4) were 11.15, 9.7, 6.2 and 5.3. Kinetics of the parallel isomerization and dissociation of a-[Ni(dimH2)]4+ in HCl/NaCl solutions were monitored spectrophotometrically at 50 degrees C. The rate of reaction in acidic solutions showed a non-linear dependency on acid concentration. The observed first order rate constant (kobs) for disappearance of a-[Ni(diamH2)]4+ (by isomerization and dissociation) in 2.0 M HCl, 0.1 M NaOH and 2.0 M NaCl were 3.05 x 10-4, 2.0(3) x 10-2 and 5.0 x 10-5 s-1 respectively. The rate of the dissociation component of the reaction of a-[Ni(diamH2)]4+ in 2.0 M HCl at 50 degrees C was 1.82 x 10-7 s-1. Acid bydrolysis kinetics of (Cu[diamH2])(ClO4)4 in hydrochloric acid and perchloric acid at 50 and 70 degrees C were studied spectrophotometrically. The reactions were slow and the observed first order rate constants were to a first approximation independent of the particular acid or its concentration. The observed first order rate constants were 1 x 10-9 and 8 x 10-9 s-1 at 50 and 70 degrees C respectively. Questions about the nature of the reaction being followed have been raised.</p>

A Spectrophotometric Investigation of the Equilibria Existing in Acidic Solutions of Chromium(VI)1-3

1953 ◽  
Vol 75 (24) ◽  
pp. 6180-6186 ◽  
Author(s):  
James Ying-peh Tong ◽  
Edward L. King
Keyword(s):  
Spectrophotometric Investigation ◽  
Acidic Solutions ◽  
Chromium Vi

Kinetic medium effects. IV. Transition state activity coefficients in mixed solvents

1972 ◽  
Vol 25 (4) ◽  
pp. 777 ◽  
Author(s):  
PT McTigue ◽  
AR Watkins
Keyword(s):  
Transition State ◽  
Activity Coefficients ◽  
Mixed Solvents ◽  
State Theory ◽  
Medium Effects ◽  
State Activity ◽  
Medium Activity ◽  
Solvent Systems ◽  
Kinetics Of ◽  
Hydrolysis Of

The kinetics of acid hydrolysis of a number of aliphatic acetals have been studied in dimethyl sulphoxide-water and dioxan-water mixtures. Where possible, experimentally measured medium activity coefficients for the acetals in the solvent systems have been used in order to calculate the transition state activity coefficients as a function of solvent composition. These activity coefficients are compared with those calculated for the transition states of other hydrolytic reactions, and with the known activity coefficients of some stable ions. The results show no features inconsistent with the assumptions of transition state theory.

Study of bioaccumulation kinetics of chromium(vi) in Acinetobacter beijerinckii type bacterium by Total Reflection X-Ray Fluorescence Spectrometry

2011 ◽  
Vol 26 (3) ◽  
pp. 511-516 ◽  
Author(s):  
R. Fernández-Ruiz ◽  
Moustafa Malki ◽  
Ana I. Morato ◽  
Irma Marin
Keyword(s):  
Total Reflection ◽  
Fluorescence Spectrometry ◽  
X Ray ◽  
Chromium Vi ◽  
Kinetics Of
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