Hydroxyethylenediaminetriacetic acid

Chelation, using ethylenediaminetetraacetic acid (EDTA), hydroxyethylenediaminetriacetic acid (HEDTA), diethylenetri-aminepentacetic acid (DTPA), phosphonates, and other compounds, together with organic acids such as citric or formic acid. Here, the reaction is ... 

NMR has been used to study the mode of complexation of La3+ and Lu3+ with 2-hydroxyethylenediaminetriacetic acid (HJ-) at 0-95 °C and various pH values. Both six-coordinated and five-coordinated (i.e. without the hydroxyl oxygen coordinated) complexes were observed, depending on the conditions.416... 

There have been several studies of the interaction of aminopolycarboxylic adds with V ". The rate of reaction of pervanadyl ion with ethylenediamine-JVN -diacetic acid (edda) is ca. 1000 times greater than that with JV-methyliminodiacetic acid (mida) or nitriloacetic acid (nta). This difference is attributed to the occurrence of edda in a monoprotonated form under the reaction conditions, whereas both mida and nta have their single nitrogen atom protonated. The acid nta (H3L) forms V02L in acidic SM-NaClO, the formation reaction being characterized by log K = —0.07 + 0.10. The kinetics of formation have also been measured, as have those of the V -hydroxyethylenediaminetriacetic acid. ... 

The synthesis and structure of bis-(2,4,6-trichlorophenolato)di-imidazolecopper(n) monohydrate is reported and claimed to be a possible model for copper binding in transferrins. The copper is at the centre of a tetragonally elongated octahedron two imidazole N and two phenolic O atoms occupy the corners of a plane and O and Cl atoms occupy axial positions. Copper(ii) and bismuth(iii) and lead(n) complexes of hydroxyethylenediaminetriacetic acid have been studied CuHL and CuL formation was suggested. ... 

Because of the involvement of metal ions in degradation reactions, the inclusion of a chelating agent is often advocated. The most commonly used chelating agent are the various salts of EDTA. In addition, (3-hydroxyethylenediaminetriacetic acid (HEDTA), diethylenetriamine-pentaacetic acid (DTPA) and nitrilotriacetate (NTA) have been assessed for their efficiency in stabilizing, e.g., isoniazid solutions (Ammar et al. 1982). 

Kinetics and activation parameters for NO reactions with a series of iron(II) aminocarboxylato complexes have been obtained (Table II) in aqueous solution (31). Rate constants for these reactions ranged from 105 to 108M-1s-1 for the series of iron(II) complexes studied. The reactions of NO with Fen(edta) (edta = ethylenediaminetetraacetate) and Fen(Hedtra) (Hedtra = hydroxyethylenediaminetriacetate) yielded activation volumes of +4.1 and +2.8 cm3 mol-1, respectively and were assigned to a dissociative interchange (Id) mechanism (31b). All of the iron(II) aminocarboxylato complexes studied followed a similar pattern with the exception of the Fen(nta) (Nta = nitriloacetic acid) complex which gave a AV value of —1.5 cm3 mol-1. The reaction of this complex with... 

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