Ethylenediaminetetraacetic acid complex

Takahashi M, Muramatsu Y, Suzuki T, Sato S, Watanabe M, Wakita K, Uchida T (2003) Preparation of Bi2Te3 films by electrodeposition from solution containing bi-ethylenediaminetetraacetic acid complex and Te02. J Electrochem Soc 150 C169-C174... 

The reactivity of metals in Reactions 11 and 12 can be influenced by the gegenion or by complexing agents (26-29). Generally, coordinated metals are less reactive. Thus, the cobaltic ethylenediaminetetraacetic acid complex is not reduced by hydroperoxides (30), although cobaltic carboxylates are reduced very rapidly (28, 31). Coordination of metallic catalysts has been generally employed for their deactivation (32). On the other hand, researchers (10) have reported that the coordination of tran-... 

Daryle H. Busch and J. C. Bailar, Jr., The Stereochemistry of Complex Inorganic Compounds. XVII. The Stereochemistry of Hexadentate Ethylenediaminetetraacetic Acid Complexes, J. Am. Chem. Soc. 75 4574 (1953). 

This investigation suggests that ethylenediamine tartrate may be a useful reagent for the polarographic determination of a variety of metal ions. A similarity to ethylenediaminetetraacetic acid complexes, also used in polarography [2], is to be expected. 

The utility of complexation titrations improved following the introduction by Schwarzenbach, in 1945, of aminocarboxylic acids as multidentate ligands capable of forming stable 1 1 complexes with metal ions. The most widely used of these new ligands was ethylenediaminetetraacetic acid, EDTA, which forms strong 1 1 complexes with many metal ions. The first use of EDTA as a titrant occurred in... 

Certain compounds, known as chelating agents (qv), react synergisticaHy with many antioxidants. It is beheved that these compounds improve the functional abiUties of antioxidants by complexing the metal ions that often initiate free-radical formation. Citric acid and ethylenediaminetetraacetic acid [60-00-4] (EDTA), C2QH2gN20g, are the most common chelating agents used (22). 

EthylenediaminetetraaceticAcid. Ethylenediaminetetraacetic acid (EDTAH has six potential donor groups two nitrogen atoms and four carboxylate groups. If EDTA 4— acts as a hexadentate ligand to a metal, the resulting complex contains five five-membered chelate rings and has a charge that is four less than that of the metal ion. 

The lanthanides form many compounds with organic ligands. Some of these compounds ate water-soluble, others oil-soluble. Water-soluble compounds have been used extensively for rare-earth separation by ion exchange (qv), for example, complexes form with citric acid, ethylenediaminetetraacetic acid (EDTA), and hydroxyethylethylenediaminetriacetic acid (HEEDTA) (see Chelating agents). The complex formation is pH-dependent. Oil-soluble compounds ate used extensively in the industrial separation of rate earths by tiquid—tiquid extraction. The preferred extractants ate catboxyhc acids, otganophosphoms acids and esters, and tetraaLkylammonium salts. 

Chromium (ITT) can be analy2ed to a lower limit of 5 x 10 ° M by luminol—hydrogen peroxide without separating from other metals. Ethylenediaminetetraacetic acid (EDTA) is added to deactivate most interferences. Chromium (ITT) itself is deactivated slowly by complexation with EDTA measurement of the sample after Cr(III) deactivation is complete provides a blank which can be subtracted to eliminate interference from such ions as iron(II), inon(III), and cobalt(II), which are not sufficiently deactivated by EDTA (275). 

Nickel also is deterrnined by a volumetric method employing ethylenediaminetetraacetic acid as a titrant. Inductively coupled plasma (ICP) is preferred to determine very low nickel values (see Trace AND RESIDUE ANALYSIS). The classical gravimetric method employing dimethylglyoxime to precipitate nickel as a red complex is used as a precise analytical technique (122). A colorimetric method employing dimethylglyoxime also is available. The classical method of electro deposition is a commonly employed technique to separate nickel in the presence of other metals, notably copper (qv). It is also used to estabhsh caUbration criteria for the spectrophotometric methods. X-ray diffraction often is used to identify nickel in crystalline form. 

Coordination Complexes. The abiUty of the various oxidation states of Pu to form complex ions with simple hard ligands, such as oxygen, is, in order of decreasing stabiUty, Pu + > PuO " > Pu + > PuO Thus, Pu(Ill) forms relatively weak complexes with fluoride, chloride, nitrate, and sulfate (105), and stronger complexes with oxygen ligands (Lewis-base donors) such as carbonate, oxalate, and polycarboxylates, eg, citrate, and ethylenediaminetetraacetic acid (106). The complexation behavior of Pu(Ill) is quite similar to that of the light lanthanide(Ill) ions, particularly to Nd(Ill)... 

A method suitable for analysis of sulfur dioxide in ambient air and sensitive to 0.003—5 ppm involves aspirating a measured air sample through a solution of potassium or sodium tetrachloromercurate, with the resultant formation of a dichlorosulfitomercurate. Ethylenediaminetetraacetic acid (EDTA) disodium salt is added to this solution to complex heavy metals which can interfere by oxidation of the sulfur dioxide. The sample is also treated with 0.6 wt % sulfamic acid to destroy any nitrite anions. Then the sample is treated with formaldehyde and specially purified acid-bleached rosaniline containing phosphoric acid to control pH. This reacts with the dichlorosulfitomercurate to form an intensely colored rosaniline—methanesulfonic acid. The pH of the solution is adjusted to 1.6 0.1 with phosphoric acid, and the absorbance is read spectrophotometricaHy at 548 nm (273). 

The complexers maybe tartrate, ethylenediaminetetraacetic acid (EDTA), tetrakis(2-hydroxypropyl)ethylenediamine, nittilotriacetic acid (NTA), or some other strong chelate. Numerous proprietary stabilizers, eg, sulfur compounds, nitrogen heterocycles, and cyanides (qv) are used (2,44). These formulated baths differ ia deposition rate, ease of waste treatment, stabiHty, bath life, copper color and ductiHty, operating temperature, and component concentration. Most have been developed for specific processes all deposit nearly pure copper metal. 

Knabe has introduced mercuric acetate plus ethylenediaminetetraacetic acid (EDTA) as an oxidizing agent for tertiary amines (74). The solvent employed is 1 % aqueous acetic acid. In this system, the complexed mercuric ion is reduced to elemental mercury. Knabe s studies have centered on the... 

Ligands bite at one or more points. Chelants bite at two or more points, so all ligands are not necessarily chelants. Chelants forming water-soluble complexes with metal ions are called sequestrants (but not all sequestrants are chelants). The most commonly employed BW chelant, ethylenediaminetetraacetic acid (EDTA) produces coordination complexes with four points of attachment and is termed a tetraden-tate ligand. 

Wood and Higginson " have made a detailed study of the kinetics of oxidation of Fe(ll) by a number of complexes of Co(IIl) with ethylenediaminetetraacetic acid (H4Y = EDTA) and hydroxyethylethylenediaminetriacetic acid (H3YOH = HEDTA). Rate data and activation parameters are quoted (Table 21) for the... 

A detailed physical examination of the purple complex formed in alkaline solution between Fe(III), ethylenediaminetetraacetic acid (EDTA) and peroxide shows it to have a composition [Fe "(EDTA)02] (togA, 3 c =4.33). This complex catalyses decomposition of peroxide, the rate-pH profile going through a maximum at pH 9-10 . 

The reaction between two polydentate complexes of Cu(II), CuY (YjH4 = ethylenediaminetetraacetic acid, Y2H4 = hydroxyethylethylenediaminetriacetic acid) and thiourea to give a Cu(I) complex of thiourea (this product was not identified), follows kinetics ... 

The reaction with a variety of complexes of Fe(II) has been examined (Table 21). The stoichiometry of the ethylenediaminetetraacetic acid (EDTA) complex reduction is 2 Fe(II) 1 RO2H in the presence of acrylonitrile but falls to 1 1 as the... 

Thennodynamic inhibitors are complexing and chelating agents, suitable for specific scales. For example, for scale inhibition of barium sulfate, common chemicals are ethylenediaminetetraacetic acid (EDTA) andnitrilotriacetic acid. The solubility of calcium carbonate can be influenced by varying the pH or the partial pressure of carbon dioxide (CO2). The solubility increases with decreasing pH and increasing partial pressure of CO2, and it decreases with temperature. 

Iron can be controlled with certain complexing agents, in particular glucono-5-lactone, citric acid, ethylenediaminetetraacetic acid, nitrilotriacetic acid, hydroxyethylethylene diaminetriacetic acid, hydroxyethyliminodiacetic acid, and the salts from the aforementioned compounds. These compounds must be added together with nitrogen-containing compounds such as hydroxylamine salts or hydrazine salts [486,643,1815]. 

Figure 17-26. Complexing agents for iron control glucono-6-lactone, nitrilotriacetic acid, hydroxyethylene diaminetetraacetic acid, and ethylenediaminetetraacetic acid.

Krokhin, O. V., Adamov, A. V., Hoshino, H., Shpigun, O. A., and Yotsuyanagi, T. Separation selectivity of some ethylenediaminetetraacetic acid and cyclohexane-1,2,-diaminetetraacetic acid complexes in column and ion electroki-netic chromatography, /. Chromatogr. A, 850, 269, 1999. 

Table 1.8 Consecutive stability constants, expressed as logXMX., of complexes of ammonia (A), ethylene diamine (B), diethylenetriamine (C) and the anion of ethylenediaminetetraacetic acid (D4 ) at 20°C and 0.1 mKN03 as indifferent electrolyte. (According to J. Bjerrum and G.

Precipitation of Fe(IIl) compounds from acid solutions as the pH increases above 2.2 is a particular problem. Complexing agents that have been used include 5-sulfosalicylic acid and citric acid (136) dihydroxymaleic acid (137) ethylenediaminetetraacetic acid (138) lactic acid (138) blends of hydroxylamine hydrochloride, citric acid, and glucono-delta-lactone (139) nitriloacetic acid blends of citric acid and acetic acid lactic acid and gluconic acid (140). 

Scale inhibitors may also be used in acidizing. These include alcohol ethoxysulfonic acids (152). Scale inhibitors are also used in water and enhanced oil recovery injection wells and include low molecular weight poly(vinylsulfonate), poly(methylmethacrylate-co-ethylenediamine) (153), bis(phosphonomethylene)aminomethylene carboxylic acid, and poly(acrylic acid-co-3-acrylamido-3-methylbu-tanoic acid). Ethylenediaminetetraacetic acid and similar complex-ing agents have been used to remove scale from formation surfaces near wellbores. 

Another attempted synthesis of Tc(III)-EDTA and Tc(III)-HEDTA complexes (EDTA ethylenediaminetetraacetic acid HEDTA A -(2-hydroxy-methyl)ethylenediamine-N,AT, iV -triacetic acid) was carried out using [Tc(tu)6]3+ as the starting complex [40]. Technetium-EDTA complexes have been synthesized by the direct reduction of pertechnetate with a suitable reduc-tant in the presence of excess EDTA [41-43]. On addition of EDTA to the Tc(tu) + solution, the intensity of the absorption spectrum decreased with time and the solution color changed from reddish orange to light brown. An electrophoretic analysis for the Tc(III)-EDTA complex showed that more than 70%... 

Synergy between primary and secondary anti-oxidants occurs and often a mixture is employed. Also included are metal complexing agents, e.g., EDTA (ethylenediaminetetraacetic acid), citric acid, the purpose of which is to deactivate extraneous metal ions that catalyse polymer oxidation. 

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