Palladium dimethylglyoxime complex

It has been mentioned that the dimethylglyoxime complexes of nickel, palladium, and platinum, and the N-methylsalicylaldimine complexes of... 

A useful spot test utilizes the fact that a suspension of red nickel dimethylglyoxime in water when treated with a neutral or acetic acid solution of a palladium salt yields the yellow palladium dimethylglyoxime, which is sparingly soluble in dilute acids. The test is best performed with dimethylglyoxime paper the latter is prepared as follows. Immerse drop-reaction paper in a 1 per cent alcoholic solution of dimethylglyoxime, dry, then immerse again in a solution of 05m nickel chloride rendered barely ammoniacal. The nickel complex precipitates wash thoroughly with water, immerse in alcohol and dry. 

Separation. Palladium is precipitated in Group II as PdS it is insoluble in ammonium polysulphide solution and therefore accompanies the elements of Group IIA. It is ultimately identified in acid solution as the dimethylglyoxime complex. 

Wang J, Varughese K (1987) Determination of traces of palladium by adsorptive stripping voltammetry of the dimethylglyoxime complex. Anal Chim Acta 199 185-189 Zereini F, Alt F (2(XK)) Anthropogenic platinum-group element emissions. Their impact on man and environment. Springer, Berlin... 

Bright yellow inner complex palladium dimethylglyoxime (I) is not soluble in acids but it dissolves in alkali hydroxides. The yellow solution contains alkali palladium dimethylglyoxime (II), in which the palladium is a constituent of an inner complex anion. 

Dimethylglyoxime. The complexes with nickel and with palladium are soluble in chloroform. The optimum pH range for extraction of the nickel complex is 4-12 in the presence of tartrate and 7-12 in the presence of citrate (solubility 35-50 fig Ni mL 1 at room temperature) if the amount of cobalt exceeds 5 mg some cobalt may be extracted from alkaline solution. Palladium(II) may be extracted out of ca lM-sulphuric acid solution. 

The reaction of aqneons green Np, or its bine ammonia complex, with colorless dimethylglyoxime (DMG) to form a vibrantly red precipitate of a 1 2 metaLDMG complex demonstrates an example of precise stereochemistry and oxime deprotonation in what is perhaps the archetypal analytical metal dioxime reaction (equation 1). This transformation certainly intrigued both authors early in their education. It is interesting to note that DMG is an excellent example of highly specific reagent because under the same reaction conditions only yellow palladium chelate is also precipitated. 

Palladium compounds have also been reported to stabilize unexposed areas to heat.199 The compounds disclosed include the complexes of triphenylphosphine, bipyridine, acetylacetone and dimethylglyoxime. Preferred compounds appear to be the acac analogs. 

Z)-A3-Alkenyl sulfones. The 7r-allylpalladium complexes of 1,3-dienes react with sodium neophylsulflnate to give a palladium complex which on treatment with dimethylglyoxime gives (Z)-sulfones with high regio- and stereoselectivity.3 Example ... 

The interference of silver in this test for gold can be avoided by precipitation and removal of silver chloride. The concentration of silver ions in a saturated solution of AgCl in 0.1 iV" hydrochloric acid is so low that in one milliliter the reaction with the reagent is no stronger than that of 0.1 y gold. 2 In the presence of chloride, the reactivity of mercury is also decreased and even completely inhibited for small amounts. Palladium salts can be removed by precipitation in acid solution with dimethylglyoxime the yellow crystalline inner complex Pd-dimethylglyoxime is formed. 

The palladium(ii) acetylacetonate-tri phenyl phosphine catalysed reaction of butadiene with water and carbon dioxide in solvents such as t-butanol or acetone has been reported to give octa-2,7-dien-l-ol as the major product together with minor amounts of octa-l,7-dien-3-ol, 1,3,7-octatriene and octadienyl ethers. In contrast aqueous potassium tetrachloropalladate with excess diene leads to pale yellow solids which were polymeric. Decomposition of these complexes with dimethylglyoxime gave a mixture of 3-methyIbutenyl ethers, (Scheme 33). The use of (—)-2,2-dimethyl-4,5-bis(diphenylphosphinomethyl)-l,3-dioxolane (DIOP) as a chiral ligand... 

The reaction of the nickel, copper, or palladium complexes M(LH)a (L= dimethylglyoxime, salicylaldoxime) with diphenylmercury and aluminium powder in refluxing toluene affords the complexes ML2Al2Ph4. Similar complexes of composition QAI2R2X2L2 (QH2=salicylaldoxime R=alkyl X=... 

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