Nitrilotriacetic acid complexes

Cannon and Gardiner [3] have been able to obtain some information on the lifetime and stability of inner sphere complexes in redox reactions. Thus the nitrilotriacetic acid complex of pentaamminecobalt(IIl) (6.2) reacts with iron(II) to give the complex (6.3). The overall rate constant k = Kk, for... 

If N,N-ethylenediglycine is present, e.g. in industrial ethylene-diaminetetraacetic acid, the wave of its cadmium complex under the given conditions is only OT V more positive than the wave for cadmium-nitrilotriacetic acid complex, and the resolution is thus difficult. Consequently, in the analysis of such mixtures the sum of the wave heights of the cadmium chelates of nitrilotriacetic acid and N,N-ethylenediglycine is first measured. The sample is then treated with hydrochloric acid to adjust the pH-value to 1 5-2-0 and boiled for 20 min. The cyclic imide formed from N,N-ethylenediglycine according to the reaction... 

Therapeutic Function Lupus Erythematosus Suppressant Chemical Name Nitrilotriacetic acid bismuth complex sodium salt Common Name —... 

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.

White, V. and Knowles, C., Effect of metal complexation on the bioavailability of nitrilotriacetic acid to Chelatobacter heintzii ATCC 29600, Arch Microbiol, 173 (5), 373-382, 2000. 

Complexes of IrIV with iminodiacetic acid (HN(CH2COOH)2), nitrilotriacetic acid (N(CH2COOH)3), and trara,s-l,2-cyclohexanediaminetetraacetic acid (L) have been studied by spectroscopic methods.43... 

The bis(nitrilotriacetato)zirconium(IV) ion, first detected by Intorre and Martell,1 has been obtained as a hydrated potassium salt by evaporation of a solution containing zirconium oxychloride and the potassium salt of nitrilotriacetic acid. On vacuum dehydration, the anhydrous complex is formed. 

One way in which cobalt dispersion can be increased is the addition of an organic compound to the cobalt nitrate prior to calcination. Previous work in this area is summarized in Table 1.1. The data are complex, but there are a number of factors that affect the nature of the catalyst prepared. One of these is the cobalt loading. Preparation of catalysts containing low levels of cobalt tends to lead to high concentrations of cobalt-support compounds. For example, Mochizuki et al. [37] used x-ray photoelectron spectroscopy (XPS) and temperature-programmed reduction (TPR) to identify cobalt silicate-like species in their 5% Co/Si02 catalysts modified with nitrilotriacetic acid (NTA). The nature of the support also has... 

The category of builders consists predominantly of several types of materials -specific precipitating alkaline materials such as sodium carbonate and sodium silicate complexing agents like sodium triphosphate or nitrilotriacetic acid (NTA) and ion exchangers, such as water-soluble polycarboxylic acids and zeolites (e.g., zeolite A). 

Chromiain(ii) Complexes.—The oxidation of chromium(ii) in alkaline solution has been studied polarographically and the reaction shown to be irreversible with = — 1.65 V vs. S.C.E. In the presence of nitrilotriacetic acid, salicylate, ethylenediamine, and edta the values were determined as —1.075, —1.33, — 1.38, and —1.48 V, respectively. The production of [Cr(edta)NO] from [Cr (edta)H20] and NO, NOJ, or NO2 suggests that this complex is able to react via an inner-sphere mechanism in its redox reactions. ... 

Another aminopolycarboxylic acid, closely related to IMDA and forming strong complexes with the lanthanide ions, is nitrilotriacetic acid (NTA). The hy-... 

It was reported that the 0-0 distance in the peroxide is 1.458 A, and that this value agreed well with values of 1.464, 1.463, and 1.469 A in the triclinic diaquo, difluoro, and nitrilotriacetic acid (NTA) complexes, respectively. The Ti-Operoxo distance (1.833 A) was compared with the values 1.834 and 1.856 A, 1.846 and 1.861 A, and 1.889 and 1.892 A, respectively, and the Ti-Owater apical distances of 2.018 A with the Ti-0 (F) values of 2.022 and 2.055 A in the triclinic diaquo, 1.853 and 1.887 A in the difluoro and 1.819 and 2.065 A in the NTA complexes. It was concluded that while the 0-0 bond distance of the peroxo group was practically the same in all the structures, there was a small but significant variation in the Ti-Operoxo and apical distances. There was progressive increase in the Ti-Operoxo bond lengths down the respective series, and a corresponding decrease in the apical bond lengths. ... 

Electroreduction of Cd(II)-nitrilotriace-tic acid and Cd(II)-aspartic acid systems was studied on DME using SWV [73]. The CE mechanism in which the chemical reaction precedes a reversible electron transfer was established. Also, the rate constants of dissociation of the complexes were determined. Esteban and coworkers also studied the cadmium complexes with nitrilotriacetic acid [74, 75] and fulvic acid [76]. The complexation reaction of cadmium by glycine was investigated by different electrochemical methods using HMDE and mercury microelectrode [77, 78]. 

Nitrilotriacetic acid (NTA) [N(CH2COOH)3] is a complexant for many metal ions (see Sec. 2.9.1.2 for information on this compound). The sodium or potassium salts of NTA have been used to complex Cd for CD of CdSe from selenosulphate solutions [10,87]. The rate of film growth depends on many factors, as discussed in Chapter 3 experimental details for CdSe deposition from this solution are given in Chapter 2. However, growth times are generally longer than for... 

The most common and best known chelant is ethylenediaminetetraacetic acid (EDTA). The related compounds diethylenetriaminepentaacetic acid (DTPA) and nitrilotriacetic acid (NTA) are also well known (Figure 10.2). EDTA is a powerful chelant that complexes strongly with most metal ions to form six-coordinate complexes. It has therefore become the first choice in most applications. Indeed, a search of the bathroom cabinet will spot EDTA on the ingredient list of many personal care formulations. DTPA is also a powerful chelant, but tends to be used more often in industrial settings. NTA has only four binding sites and is used more often where hardness ions require control, such as in cleaning, for example, hard surface cleaners, dishwashing, and the dairy industry. 

Figure 12-4 Structures of analytically useful chelating agents. Nitrilotriacetic acid (NTA) tends to form 2 1 (ligand metal) complexes with metal ions, whereas the others form 1 1 complexes.

Complexes with IMDA and related ligands.—A series of three substituted aminoacetic acids, IMDA, HIMDA and NTA constitute another set of very interesting ligands. The stability constants of the iminodiacetic acid (IMDA) [ 465], N-hydroxyethyliminodiacetic acid (HIMDA) 466 and nitrilotriacetic acid (NTA) complexes are compared in Table 34. Based on log k values the following trend of stability is noted. The... 

Thus the rate of electrolysis of O is determined by the magnitude of k in concert with the diffusion process. Metal complexes such as cadmium nitrilotriacetic acid Cd(NTA), in which the metal complex first dissociates to form a hydrated metal ion that then undergoes reduction, fall into this category [6] ... 

These acids have been investigated in relation to the particular influence of the substituent R on the stability of the metal complexes formed. This is because the tridentate iminodiacetate group ensures a generally quite elevated stability of the complexes formed. Of these ligands nitrilotriacetic acid (nta R = CH2C02H) is the most important because it has found various applications. 

The complexers maybe tartrate, ethylenediaminetetraacetic acid (EDTA), tetrakis(2-hydroxypropyl)ethylenediamine, nitrilotriacetic 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 in deposition rate, ease of waste treatment, stability, bath life, copper color and ductility, operating temperature, and component concentration. Most have been developed for specific processes all deposit nearly pure copper metal. 

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