Cadmium ethylenediamine

Cadmium dichromate, molecular formula, properties, and uses, 6 56 It Cadmium dihydrogen phosphate, 4 514 Cadmium diphosphide, 4 510 Cadmium electrodes, 3 408 standard potential, 3 413t Cadmium electroplating, 24 749 Cadmium ethylenediamine hydroxide, solvent for cotton, 8 21 Cadmium fluoride, 4 512 physical properties of, 4 508t Cadmium fluoroborate, 4 511 Cadmium fluoroborate hexahydrate,... 

A considerable amount of work has been devoted to the action of ionizing radiation on polymeric carbohydrates in the solid state, in particular with regard to its effect on the mechanical properties even though some chemical effects have also emerged. For a recent review see [99]. Of these polymers, cellulose has been the most studied (c/. [99, 100]). Native cellulose is locally crystalline. Determination of chain breakage by radiolysis has usually been done after dissolution through complexation, e.g. as the copper-ammine complex (Schweizer s reagent), or the cadmium-ethylenediamine complex. 

The molecular cellulose chains have varying lengths. Measurements of the chain length require that cotton be in solution. Solvents for this purpose include cuprammonium hydroxide solution, phosphoric acid [7664-38-2], nitric acid [7697-37-2], quaternary ammonium bases, cadmium ethylenediamine hydroxide [14874-24-9], cupriethylenediamine hydroxide [111274-71-6] (76), dimethylacetamide [127-19-5]-lithium chloride [7447-41-8] (DMAC—LiCl), and... 

For the cadmium-ethylenediamine complexes, the lengths of the M-N bonds are practically independent of the coordination number of the cadmium ion. The values of enthalpy changes of each step of the reactions are also invariable (-14 kJ mol for each Cd-N bond), which are the same as that of the Cd(NH3) complex. Therefore, the Cd-N bond strength of these complexes are almost the same, irrespective of their structures. 

Nitrite can be deterrnined by reaction with sulfanilamide to form the diazo compound, which couples with /V-(1-naphthyl)ethylenediamine dihydrochloride to form an intensely colored red azo dye. Nitrate can be deterrnined in a similar manner after reduction to nitrite. Suitable reducing agents are cadmium filings or hydrazine. This method is useful at a nitrogen concentration of 10 -lO " M. 

Spencer and Brewer [111] have reviewed methods for the determination of nitrate in seawater. Classical methods for determining low concentrations of nitrate in seawater use reduction to nitrite with cadmium/copper [ 112,116,117] or zinc powder [113] followed by conversion to an azo dye using N- 1-naphthyl-ethylenediamine dihydrochloride and spectrophotometric evaluation. Malho-tra and Zanoni [114] and Lambert and Du Bois [115] have discussed the interference by chloride in reduction-azo dye methods for the determination of nitrate. 

Table 3.5 Thermodynamic Parameters of Reaction of Cadmium(II)-Ammonia Complex with Ethylenediamine... 

The stability constants of the formed chloro-cadmium complexes in aqueous solution [135] and water-2-butanone mixtures [136] were also determined, using potentiometric measurements. The influence of hydrogen bonding of the solvent on the stability of Cd(II)-ethylenediamine complexes in water-DM SO mixtures was analyzed using pH and calorimetric measurement [137]. In five water-acetonitrile mixtures, the stability constants of Cd(II) and Zn(II) cyanide complexes were determined [138]. 

The PVC membrane electrode based on new Schiff base complexes of 2,2-[(l,3,dimethyl-l,3-propanediylidene)dini-trilojbis-benzenethiolato with Cd(II) [381] and cadmium-salen N, Ai -bis-salicyli-dene-l,2-ethylenediamine) complex [382] were used as the selective electrodes for tiocyanate ions. 

A series of complexes of the type ML(SCN) (C104)2-, (M - Zn, Cd, or Hg x = 1 or 2) has been prepared where L is en and its tetramethyl derivative, diethylenetriamine and its pentamethyl derivative, triethylenetetramine and its hexamethyl derivative, and bis(ethylenediamine). The complexes are either monomeric with four-, five- or six-coordinate metal, or polymeric containing bridging thiocyanate the perchlorate is always ionic. The thiocyanate is generally bonded through nitrogen to zinc and cadmium (and through sulfur to mercury).181... 

The preparation of some mixed ethylenediamine-oxalate or other ligand complexes of cadmium(Il) has been reported.190-192 The reaction of a mixture of cadmium oxalate and CdX2 (X = Cl, Br, I or SCN) with ethylenediamine gives the complexes Cd(en)X(C204)o.s. The... 

Dialysis studies122 of ofellulose and dextran in aqueous solutions of barium hydroxide, sodium hydroxide, and cadoxene (cadmium hydroxide in ethylenediamine) showed no difference in complexing ability between the two polysaccharides. Furthermore, in solutions having equal base normality, Ba2 , Na ,, nd Cd (ethylenediamine) had loughly equal complexing abilities. 

Edta can also be obtained by catalytic oxidation of tetra(hydroxyethyl) ethylenediamine (2) by a process developed by the Carbide and Carbon Chemical Corporation (equation 5).8,9 The amino alcohol is heated at 220-230 °C for several hours with sodium or potassium hydroxide and cadmium oxide as a catalyst. Hydrogen is liberated and Na4edta is obtained. 

Standard Enthalpy and Entropy Changes on Forming Complexes between Cadmium Ion and Methylamine or Ethylenediamine (en)... 

In the presence of cadmium, nitrate (N03 ) is reduced to nitrite (N03). The nitrite produced is diazotized with sulfanilamide. This is followed by coupling with N-(l-naphthyl)-ethylenediamine to form a highly colored azo dye. The intensity of the color developed is measured by a spectrophotometer or a filter photometer at 540 nm. The concentration of oxidized N/L (N03-N plus NO AN) is read from a standard curve prepared by plotting absorbance (or transmittance) of standard against N03-N concentrations. 

This method can be used to determine the nitrate content in precipitation within the range from 0.02 to 0.23 mg NO3-N/L (0.1-1.0 mg N03/L). Nitrate is reduced to nitrite using cadmium treated with copper sulfate as reducing agent in the presence of ammonium chloride. With this method the sum of nitrate and nitrite is determined. Nitrite and sulfanilamide form a diazo compound that couples with N-(l-naphthyl)-ethylenediamine dihydrochloride to form a red azo dye. The concentration in the solution is determined spectrophotometrically at 520 nm. Note that nitrite will interfere with the determination of nitrate. 

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