Ethylenediamine-diacetic acid EDDA

The formation of 1 1 complexes between ethylenediamine-N, N1 -diacetic acid (edda) and Zn11 or Cd11 have been studied by calorimetric (AH) and potentiometric techniques.389 Earlier studies had omitted to allow for protonation reactions of the ethanoato groups in the ligand. Thermodynamic parameters for edda lie between those of nitrilotriacetate and triethylenetetra-mine. Edda appears to undergo a slow metal-ion-catalyzed hydrolysis in aqueous acid solution. 

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. ... 

EDMA - Ethylenediamine monacetic Acid EDDA - Ethylenediamine diacetic Acid... 

Namely, the reaction of 2-thioxothiazolidin-4-one N-hexanoic acid (116) with 2,5-dimethyl-l-phenylpyrrol-3-carboxaldehyde (117) in methanol under the catalytic action of ethylenediamine diacetate (EDDA) yields 5-[(2,5-dimethyl-l-phenylpyrrol-3-yl)methylidene]-2-thioxothiazolidin-4-one N-hexanoic acid (118) in 79% yield. The hydroxamate derivative of 118 is prepared by reacting this compound with 0-(tetrahydro-2H-pyran-2-yl)hydroxylamine followed by treatment with p-toluenesulfonic acid in methanol to afford compound 121 in 60% yield. Esterification of compound 118 is carried out by using methyl iodide in acetonitrile in the presence of sodium carbonate to give compound 120. The 5-(cyclohexyl)methylidene analogue (119) is obtained in 42% yield by direct reaction of compound 116 with cyclohexanecar-boxaldehyde in methanol under the catalytic action of EDDA. 

EDTA, ethylenediamine tetraacetic acid NTA, nitrilotriacetic acid HEEDTA, hydroxy-ethylethylene EDTA DTPA, diethylenetriamine pentaacetic acid EDDDA, ethylene diamine-/V,/V -diacetic-/V,/V -dipropionic acid EDDA, /V,/V -ethylene diamine diacetic acid CyDTA, cyclohexylene diamine tetraacetic acid. 

Abbreviations used for ligands en = ethylenediamine edta = anion of ethylenediamine-tetraacetic acid [(ethylenedinitrilo)tetraacetic acid] edda = anion of ethylenediamine-, A -diacetic acid [(ethylenediimino)diacetic acid A ,A -ethylenediglycine], Lower case letters are used for edta and edda as recommended by the I.U.P.A.C. nomenclature rules, even though this is not current practice in the literature. 

The behaviour in solution of dimethyltin(IV) complexes containing different aminopoly-carboxylic acids were also investigated . The X-ray crystal structure analyses of the tin complexes with Af-methyliminodiacetate (mida), pyridine-2,6-dicarboxylate (pdc) and ethylenediamine-Al,Af -diacetate (edda) revealed dimeric structures for the first two compounds and a monomeric structure for the complex dimethyltin (edda). In contrast, the dimethyltin(IV) complex (137) with ethylenediamine-Af,Af,Af, Af -tetraacetate (edta) and water is a polymer in which each tin atom adopts a distorted pentagonal-bipyramidal configuration with the two methyl groups in axial positions. 

---