Diamine complexes cadmium

Cadmium(II) complexes with L207 have been synthesised by the reaction of butane-2,3-dione or benzil with the corresponding aliphatic diamines in the presence of Cd as the template (Eq. 2.126) [247],... 

The ligand 6,13-dimethyl-l,4,8,ll-tetra-azacyclotetradecane-6,13-diamine coordinates as a hexadentate ligand to zinc in neutral aqueous solution. Potentiometric titrations were used to determine the stability constant for formation. The pXa values were determined for five of the six possible protonation steps of the hexamine (2.9, 5.5, 6.3, 9.9 and 11.0).697 Studies of the syn and anti isomers of 6,13-dimethyl-1,4,8, ll-tetraazacyclotetradecane-6,13-diamine reveal that they offer different shapes for metal binding, which is reflected in the stability constants for 1 1 zinc ligand ratio complexes. The selectivity of binding to the zinc ion compared to the cadmium(II) ion by both isomers is significant.698... 

The cadmium complexes were also investigated potentiometrically. Using this method, the complexes of cadmium with asparagine [128], taurine [129], A -(6-ami-no-3-methyl-5-nitroso-4-oxo-3,4-dihydro-pyrimidin-2-yl)glycine [130], succinate and malate [131], acetate at different temperatures [132], pyridine oxime ligands [133], 2-hydroxypropene-l,3-diamine-Af,Af,Af, A -tetraacetic acid [134] were studied. The stoichiometry and stability constants of these complexes were determined. 

Both zinc and cadmium form numerous complexes with amine ligands, ranging from NH3 through diamines such as ethylene diamine and substituted propylene diamines,54 to a variety of macrocycles.55 56 Pyridines and pyrazoles are also good ligands.57,58 In the case of 1,3,5-triaminocyclo-hexane, a regular octahedral complex cation is formed, as shown in Fig. 15-4. With 3-Me-pyrazine, tetrahedral [Zn(C4N2H6)4]2+ is formed.59... 

Among the best-known nonderivatizing solvent systems is a combination between copper, alkali, and ammonia termed Schweizer s reagent. Solutions of cuprammonium hydroxide have been used for both analytical and industrial cellulose dissolution. Regenerated fibers with silk-like appearance and dialysis membrane have been (and partially continue to be) industrial products on the basis of cellulose dissolution in cuprammonium hydroxide. The success of this solvent is based on the ability of copper and ammonia to complex with the glycol functionality of cellulose as shown inO Fig. 11. Because of the potential side reactions (oxidation and crosslinking, Norman compound formation), alternatives to both ammonia as well as copper have been developed. Cuen and cadoxen are related formulations based on the use of ethylene diamine and cadmium, respectively. The various combinations of alkali, ammonia. 

Solubility parameters (MPa) / alkalies Cuprammonium hydroxide Cupriethylenediamine hydroxide Cadmium ethylene diamine hydroxide Iron sodium tartrate complex Soluble (complex formation) 32.02 (1)... 

Cupriethylenediamine hydroxide Cadmium ethylene diamine hydroxide Iron sodium tartrate complex formation) ... 

In the second example, O Brien et al. (1849) prepared [M S2CN(Me) CH2CH2CH2NMe2 2] (M = Zn, Cd) from trimethylpropane-1,3-diamine. The zinc complex 483 is polymeric. Each five-coordinate metal center carries two chelating dithiocarbamates and are linked via coordination of a pendant dimethylamino group. Interestingly, the analogous cadmium complex adopts a dimeric centrosymmetric structure in the solid state. Although these examples... 

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