Gold complexes iodides

Gold(III) iodide complexes may be easily reduced to gold(I) in many cases. For example, the equilibrium constant for equation (63) in aqueous solution is 200 M-1, corresponding to about... 

Acetylide complexes were also produced in liquid ammonia in the reaction of gold(I) iodide with potassium acetylides (65). With excess K(C=... 

CPh), the complex K[Au(C=CPh)2] was obtained, whereas the presence of excess K(C CH) yielded K2[HC CAuC=CAuC CH] and K[Au-(C CH)2], The addition of HC CCH2CR2CN (R = Me or Ph) to gold(I) iodide in liquid ammonia gave (66) the gold(I) acetylide, whose infrared spectrum indicated a d7r-p7r interaction between the gold atom and the alkynyl group. 

A complex iodide having the formula CsI,AuI3 is produced in glistening, black crystals by the interaction of gold dichloride and caesium iodide.1... 

Propargyl alcohols can be converted into vinyl iodides and bromides using a dual catalyst approach (Scheme 7.119) [183]. The combination of a common gold complex with a molybdenum species generated a highly active catalyst for this reaction. The precise... 

Gold.—Methyl iodide readily oxidatively adds to the anionic complex Li+[AuMea(PPhs)] to yield [AuMe3(PPha)]. Alkyl iodides add to the three-coordinate complexes to give predominantly rra/w-products, tran -[AuMeaR-(PPhg)], although some cis-product can be isolated when the R group is not too bulky. Rates of reaction of alkyl halides RX decrease in the order X = I> Br>Cl and R = Me>Et>Bu i. The reaction between [AuMeCPPhs)] and... 

Rubidium metal alloys with the other alkaU metals, the alkaline-earth metals, antimony, bismuth, gold, and mercury. Rubidium forms double haUde salts with antimony, bismuth, cadmium, cobalt, copper, iron, lead, manganese, mercury, nickel, thorium, and 2iac. These complexes are generally water iasoluble and not hygroscopic. The soluble mbidium compounds are acetate, bromide, carbonate, chloride, chromate, fluoride, formate, hydroxide, iodide. 

Determination. To an aliquot of the silver(I) solution containing between 10 and 50 pg of silver, add sufficient EDTA to complex all those cations present which form an EDTA complex. If gold is present (>250 xg) it is masked by adding sufficient bromide ion to form the AuBr4 complex. Cyanide, thiocyanate or iodide ions are masked by adding sufficient mercury(II) ions to complex these anions followed by sufficient EDTA to complex any excess mercury(II). Add 1 mL of 20 per cent ammonium acetate solution, etc., and proceed as described under Calibration. 

The reaction is a sensitive one, but is subject to a number of interferences. The solution must be free from large amounts of lead, thallium (I), copper, tin, arsenic, antimony, gold, silver, platinum, and palladium, and from elements in sufficient quantity to colour the solution, e.g. nickel. Metals giving insoluble iodides must be absent, or present in amounts not yielding a precipitate. Substances which liberate iodine from potassium iodide interfere, for example iron(III) the latter should be reduced with sulphurous acid and the excess of gas boiled off, or by a 30 per cent solution of hypophosphorous acid. Chloride ion reduces the intensity of the bismuth colour. Separation of bismuth from copper can be effected by extraction of the bismuth as dithizonate by treatment in ammoniacal potassium cyanide solution with a 0.1 per cent solution of dithizone in chloroform if lead is present, shaking of the chloroform solution of lead and bismuth dithizonates with a buffer solution of pH 3.4 results in the lead alone passing into the aqueous phase. The bismuth complex is soluble in a pentan-l-ol-ethyl acetate mixture, and this fact can be utilised for the determination in the presence of coloured ions, such as nickel, cobalt, chromium, and uranium. 

Abdou, H.E., Mohamed, A.A. and Fackler, J.P. Jr (2004) Oxidative addition of methyl iodide to dinuclear Gold(I) amidinate complex schmidbaur s breakthrough reaction revisited with amidinates. ZeitschriJiJurNaturforschungB. A Journal of Chemical Sciences, 59, 1480-1482. 

Univalent halides—e.g. NH l.AgCl CsCl.CuCl 2KCl.CuCl etc. The halides of the alkali metals do not often unite together to form stable complexes. Univalent copper, silver, and gold form double chlorides with the alkali halides, while the corresponding double bromides of silver and gold and the double iodide of silver have not been made. The facts can be summarized in the form of a scheme due to P. Pfeiffer (1902), where the hyphens represent compounds which have not yet been prepared ... 

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