Acid Complexes In Solution Research Articles

ChemInform Abstract: FORMATION OF ALUMINIUM ‐ TARTARIC ACID COMPLEXES IN ACIDIC SOLUTION

Chemischer InformationsdienstVolume 4, Issue 38 Organoelement Compounds ChemInform Abstract: FORMATION OF ALUMINIUM - TARTARIC ACID COMPLEXES IN ACIDIC SOLUTION BOGUSLAWA HURNIK, BOGUSLAWA HURNIKSearch for more papers by this author BOGUSLAWA HURNIK, BOGUSLAWA HURNIKSearch for more papers by this author First published: September 18, 1973 https://doi.org/10.1002/chin.197338306AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume4, Issue38September 18, 1973 RelatedInformation

ChemInform Abstract: THE HYDROLYSIS OF FERRIC COMPLEXES, MAGNETIC AND SPECTROPHOTOMETRIC STUDIES OF AQUEOUS SOLUTIONS OF FERRIC SALTS

AbstractChloro‐, Aquo‐, Nitrato‐ und Sulfato‐Fe(III)‐Komplexe werden in saurer Lösung bei Temperaturen unter 70°C unter Bildung mehrkerniger Fe(III)‐Komplexe hydrolysiert.

The Hydrolysis of Ferric Complexes. Magnetic and Spectrophotometric Studies of Aqueous Solutions of Ferric Salts

Abstract Ferric chloro, ferric aquo, and ferric sulfato complexes in acidic solutions have been hydrolyzed at temperatures below 70°C to form polynuclear complexes of iron(III). Magnetic and spectrophotometric studies have then been carried out in order to clarify the nature of the polynuclear complexes. From these studies, their empirical formulas are presumed to be Fe2(OH)2Cl2O, Fe2(OH)3(NO3)3, Fe2(OH)3(SO4)3⁄2, and Fe3(OH)2(SO4)7⁄2. The iron ions in these polynuclear complexes are in a high spin state, as are those in the ferric complexes, iron oxides, and oxyhydrates. It is proposed that, in all these polynuclear complexes except Fe3(OH)2(SO4)7⁄2, edge-shared octahedral dimer units are antiferromagnetically linked with one another by hydroxy or oxo bridging. When the hydrolysis temperature is raised, these polynuclear complexes are further hydrolyzed to form precipitates. The complexes of Fe2(OH)2Cl2O, Fe2(OH)3(SO4)3⁄2, and Fe3(OH)2(SO4)7⁄2 give β-FeOOH, α-FeOOH, and RFe3(OH)6(SO4)2 (R=Na, K or NH4) respectively, whereas the complex of Fe2(OH)3(NO3)3 gives α-FeOOH or α-Fe2O3, depending on the temperature.

Kinetics and mechanism of substitution reactions of complexes — XLI: Aquation of the complexes Na[Co(DH) 2(NO 2) 2] and [Co(DH) 2(NO 2)(H 2O)] in basic solutions

In basic solutions the aquation rate of Na[Co(DH) 2(NO 2) 2] and of [Co(DH) 2(NO 2)(H 2O)] (DH 2 ≡ dimethylglyoxime) increases with increasing hydroxide ion concentration. This phenomenon is explained in terms of a protolytic pre-equilibrium and of the parallel aquation of both conjugated acid and base. Aquation rate constants are reported for various hydroxide ion concentrations and for different temperatures. From these experimental rate constants the acidity constants of the conjugated acids and rate constants for the equation of the conjugated bases are derived. Activation enthalpy and entropy values of the aquation of the conjugated bases are compared with kinetic parameters for the aquation of the same complexes in acid solutions. Relations between activation enthalpy and structure are discussed.

Spectrophotometric determination of small amounts of reagents used in solvent extraction processes: α-Hydroxyoximes

A rapid spectrophotometric method for the determination of small amounts of α-hydroxyoximes (liquid ion-exchange reagents LIX-63, -64 and -64N) in aqueous solution is described. The method utilizes the selectivity of these reagents for copper to form yellow/green complexes in acidic solution, which are quantitatively extracted into a non-polar solvent and determined spectrophotometrically. None of the metal ions expected to be present in feed solutions to solvent extraction processes with these reagents interferes. The method is suitable for the determination of the three reagents in the p.p.m. range in both aqueous solutions and slurries, with a relative standard deviation of ± 2–3%.

The preparation and characterization of the µ-amido-µ-oxalato-bis[tetra-amminecobalt(III)] complex, and the kinetics of reduction with Cr2+and V2+

The chloride salt of the protonated form of the µ-amido-µ-oxalato-bis[tetra-amminecobalt(III)] complex, has been prepared and characterized. The perchlorate salt has also been prepared and it would appear that the oxalate [graphic omitted] bridge is only 50% protonated in this solid. From spectrophotometric measurements on the complex in acidic solutions at 15–45°, µ= 2·0M(LiClO4), values of the protonation constant K= 18 ± 2 l mol–1 have been determined. Reduction with chromium(II), 2Cr2++(CoIII)2→ 2Co2++(CrIII)2, proceeds in two stages, each involving attack of the chromium(II) and reduction of cobalt(III). Both protonated (ka) and unprotonated (kb) forms participate in the first stage of the reaction (k1), and the rate law (Cr2+ in large excess) is as in (i) [graphic omitted]. At 25° and µ= 2·0M(LiClO4), ka= 1·45 ± 0·07 l mol–1 s–1, and kb= 35·2 ± 0·4 l mol–1 s–1. The second stage of the reduction is independent of [H+] as in (ii) [graphic omitted] and k2= 1·88 ± 0·05 l mol–1 s–1 at 25°. Information regarding the spectrum of the intermediate and final product has been obtained. The reduction with V2+ also proceeds in two stages, the first of which is directly measurable. The rate law observed is of the same form as (i), and again both the protonated (kc) and unprotonated (kd) forms are reactive. At 25° and µ= 2·0M(LiClO4), kc= 3·51 ± 0·04 l mol–1 s–1 and kd= 22·7 ± 0·4 l mol–1 s–1. Activation parameters have been obtained for ka, kb, k2, kc, and kd.

Lanthanum citrate complexes in acid solutions

The complexes present at 2O °C in acidified 1.O M NaCl containing 1:1 mixtures of LaCl 3 and citric acid are LaH 2cit (log k f = 2.52), LaHcit (log K f = 3.8 o), and Lacit (log K f = 6.65).

Riboflavin-indoles interaction in acid solution.

It was ascertained that riboflavin interacted with several indoles to form 1:1 complex in acid solution, and the formation of the complex was due to charge transfer forces judging from the absorption spectra. Charge transfer forces seemed to be very weak for the stabilization of the complexes. It was found that in relation to the solvent effect on stable complex formation, the extent of polarity as well as the acidity of the solvent was closely involved.

Copper‐flavonoid complexes in acidic solutions

Summary. Amperometric titration was used to detect complexing of cupric ions by flavonoids in solutions more acid than pH 4.5. Strongest complexing ability was shown by the 3‐hydroxy‐4‐carbonyl system although the 5‐hydroxy‐4‐carbonyl system also complexed with copper in acid solution. the o‐diphenolic grouping did not form complexes under the conditions used. Complexing ability was enhanced by the presence of hydroxyl groups in conjugation with the carbonyl group. Quercetin was the only flavonoid tested capable of complexing copper at pH 2.3. the significance of these results to the antioxidant action of flavonoids in fruit juices is discussed.

Microdetermination of thorium

Abstract Thorium was determined titrimetrically by dissolving the complex, formed by boiling thorium nitrate and sodium rhodizonate together, in dilute H2SO4. The dissolved complex in acid solution was titrated against standard ceric sulfate solution using N-phenylanthranilic acid as indicator. Complex is formed in the ratio of 1:2. Maximum error is 0.9%. The range in which thorium was estimated varied from 11.2663 × 10−4 to 45.0752 × 10−4 mg/liter. Interference by certain metal ions was observed.

On the formation of Cu II-tartrate complexes in acid solution

The formation of complexes between Cu 2+ and tartrate ions (L) was studied (25°C, 1M Na +(ClO 4 −)) by measuring the e.m.f. of the cells: ▪ The solutions had the general composition: B M in Cu II, H M in H +, [Na +] = 1.00 M [ClO 4 −] = (1+H+2B−2A)M and L = A M. The experimental data can be explained according to the following equilibria: ▪

The effects of polyamines on the melting of polyriboinosinic acid plus polyribocytidylic acid complex in solution.

Abstract The thermal transition profile (melting profile) of the double-helical complex of polyriboinosinic acid plus polyribocytidylic acid, poly(I+C), into random coils in solution has been examined by the observation of the ultraviolet absorbance at 248 mμ of the solution. The effects of Na+, Mg2+, NH4+, CH3NH3+(CH2)nNH3+ (where n=2, 3, 4, 5, 6, and 8), spermidine, spermine, actinomycin D, and poly-l-lysine upon the melting profile have been observed. Among the diamines examined, that with n=3 has been found to have the maximum effect. Poly-l-lysine has been found to form a complex with poly(I+C) in the solution with a stoichiometric mole ratio of NH2 : P=0.5 : 1.

Yeast aldehyde dehydrogenase

Summaryo1.A soluble enzyme has been isolated from baker's yeast which catalyzes the reduction of pyridine nucleotides by several aldehydes. With acetaldehyde, the most rapidly utilized substrate, the oxidative product is acetic acid. A reverse reaction was not demonstrated.2.Potassium ions and cysteine are essential for the enzyme's activity. Rubidium or NH4+ can be substituted for K+, and glutathione for cysteine. Lithium, Na+, and Cs+ inhibit the reaction.3.A procedure is described for concentrating the enzyme about 300-fold from crude yeast juice. This procedure is largely dependent upon heat precipitation of inactive proteins in the presence of nucleic acid and precipitation of the enzyme as a nucleic acid complex in acid solution, followed by precipitation from saturated NaCl. A soluble enzyme has been isolated from baker's yeast which catalyzes the reduction of pyridine nucleotides by several aldehydes. With acetaldehyde, the most rapidly utilized substrate, the oxidative product is acetic acid. A reverse reaction was not demonstrated. Potassium ions and cysteine are essential for the enzyme's activity. Rubidium or NH4+ can be substituted for K+, and glutathione for cysteine. Lithium, Na+, and Cs+ inhibit the reaction. A procedure is described for concentrating the enzyme about 300-fold from crude yeast juice. This procedure is largely dependent upon heat precipitation of inactive proteins in the presence of nucleic acid and precipitation of the enzyme as a nucleic acid complex in acid solution, followed by precipitation from saturated NaCl.

Quinaldinic acid as a micro-reagent

A method for the micro-estimation of zinc by means of quinaldinic acid in the presence of copper, silver or mercury individually, or in the presence of both silver and mercury, is described. It depends upon the use of thiourea for masking the reaction of copper, mercury and silver ions with which it forms stable complexes in acid solution. In the case, where copper is present, a previous addition of sodium bisulphite is necessary to reduce the cupric to cuprous ion. Zinc is precipitated as usual in acetic acid solution by the addition of sodium quinaldinate.