Metal nitrilo-acid complexes

Organic compound (such as ethylenediamine-tetraacetic acid (EDTA) or nitrilo-triacetic acid (NTA) having the ability to take metal ions in water and produce soluble, coordinate-bond complexes. Chelants are commonly used in BW deposit control treatments and various cleaning formulations. 

Acetic acid, ethylenenitrilo[(hydroxyethyl)nitrilo]tri-iron(III) complexes, 2,788 Acetic acid, hexamethylenediaminetetra-synthesis, 2,779 Acetic acid, iminodi-chelating resins mineral processing, 6,824 metal complexes, 1,554 2, 788... 

Low-valent Ru(II) [150] and Rh(I) complexes catalyze aldol and Michael reactions of 2-nitrilo esters. The sequence is thought to be initiated by nitrile complexation to the transition metal. This Lewis acid-activation is followed by an oxidative addition to give a metal hydride and a nitrile complexed enolate as shown in Sch. 36. Examples including diastereoselective Ru(II) catalyzed reactions [151] and enantioselective Rh(I)-catalyzed reactions [152-154] with the large trans-chelating chiral ligand PhTRAP are shown in Tables 8 and 9. 

C7H3NO3S, o-BenzosuIfimide (saccharin) metal complexes, 23 47 C7HgNP,PoIy[nitrilo(methyIphenyIphosphor-anylidyne)], 25 69, 72-73 C7HgSe, Poly(methylphenylsilylene), 25 56 C7H10, 1,3-CycIoheptadiene ruthenium complex, 22 179 C7Hi7F3NOPSi, Phosphinimidic acid, P,P-dimethyl-Ai-(trimethylsilyl)-... 

Derivatives of iminodiacetic acid, NH(CHjCOOH), are most successful sequestering agents (Summersgill, loc. cit.). Two compounds of this class have had commercial success, namely, nitrilo triacetic acid, N(CH,.C00H)3, and ethylenediaminetetra-acetic acid, (COOH.CH,)jN.CH2.CH,.N(CH,.COOH)j. Ethylenediaminetetra-acetic acid, often abbreviated to E.D.T.A., has virtually displaced nitrilo triacetic acid because the complexes which it makes with metallic ions are more stable. The nature of the complex molecules are shown below ... 

Many complexing agents are hardly degradable and therefore can be observed in environmental waters. Since the complexing agents such as ethylenediamino tetra-acetic acid (EDTA), nitrilo triace tic acid or aminophosphonic acids are extremely polar compounds, they were determined preferentially by ESl-LC-MS. IC interfaced by ESI to the MS allowed the determination of EDTA in pg L quantities without any pre-concentration [397]. Metal complexes of EDTA were very stable and could be observed after ESI-LC-MS as [M-i-metal] ions in positive ionisation mode [398]. ESI CE-MS was applied to separate and to quantify the stabile Ni-EDTA complexes [399]. 

Xylidyl blue (Magon) Magnesium forms a colored complex with sulfonated Magon in a strongly basic medium. The absorbance maximum of the complex is at 548 nm. Calcium interference is avoided by the addition of ethylene-bis-(oxyethylene-nitrilo)-tetraacetic acid (EGTA) and interference by heavy metals by using cyanide. 

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