Bismuth, Complexes

Therapeutic Function Lupus Erythematosus Suppressant Chemical Name Nitrilotriacetic acid bismuth complex sodium salt Common Name —... 

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. 

Two salts involving bismuth complexes as both ions have been structurally characterized (116). [Bi2Cl4(tu)6][BiCl5(tu)] consists of a binuclear centrosymmetric dication (117), and bismuth adopts a six-... 

Bismuth complexes involving ketoalkoxide ligands are rare and are represented by comprehensively characterized examples of an ethyl-maltolatfi Bi(emal)3 (173), a tris(acetylacetonate) (174), an acetylacet-onate Bi(p,-OiPrXO Pr)(i/-acac) (175), and series of tropolonate deriva-... 

The physical properties of some bismuth complexes containing Si, Ge and Sn ligands are listed in Table 23. 

Dalzin (bis(allylthiocarbamido)hydrazine) forms sparingly soluble complexes (29) in which it is bonded through sulfur and nitrogen atoms (Section 10.2.7) but the bright orange-red bismuth complex can be extracted into chloroform for a spectrophotometric determination provided cyanide is present to mask copper. 1,4-Diphenylthiosemicarbazide PhNHNC(SH)NHPh can be used for the spectrophotometric determination of ruthenium after extraction of its violet-red complex into chloroform. 

Re(CO)5]+ and [Te]2. Complex 173 contains a trigonal-pyramidal tellurium atom and is isoelectronic with the trimanganese-bismuth complex 105. 

Dahl (175). The basic structure is defined by an octahedral core with trans-tellurium atoms and is isoelectronic with the ruthenium complex 183. Both clusters may also be compared with the ruthenium and osmium bismuth complexes, 125 and 129, which, although octahedral, contain two less electrons. A complex containing an additional carbonyl group, viz. [Te2Co4(CO)u], 185, has been described by Rauchfuss (172) as resulting from the reaction... 

The use of much-neglected bismuth derivatives for the oxidation of organic compounds has been reviewed.74 Bismuth(III) carboxylates, obtained by reaction of Bi2C>3 with pyridine mono- and di-carboxylic acids and with phthalic acid, act as catalysts for the oxidation of styrene oxide to benzoic acid in DM SO in the presence of 02.75 It is proposed that the bismuth may activate both epoxide and oxidant in a solvate, from which dimethyl sulfide evolution and elimination leads to a ketoalkoxide-bismuth complex (and hence to the initial product, 2-hydroxyacetophenone). Further oxidation to tlie ketoaldehyde and acid requires molecular oxygen, but is also found to be catalysed by bismuth. 

Bismuth Complexes with Group 15-based Ligands... 

Bismuth readily forms bonds to many metals. The most direct route to transition metal - bismuth complexes is the reaction of metal-carbonyl anions with bismuth halides. The complexes Bi Mn(CO)5 3, Bi CpMo(CO)3 3, Bi Fe(CO)2Cp 3, Bi Co(CO)4 3, Bi Ru(CO)2Cp 3, and Bi Ni(CO)C5Mes 3 (Scheme 2, (24)) are obtained by this method. 

---