Ethyl acetate cobalt complex

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. 

Pyridine ligands 186 are monodentate, forming complexes of the kind presented by 189. Pyridine is coordinated in the same way in copper acetate 194 [314] and iron rhodanide complexes [315], adducts of cobalt complex with fe(salicylidene)ethyle-nediamine 195 [316] and nickel chelate, formed by tridentate N,S-donor azomethine ligand 196 [317] ... 

Azo compounds are very efficient in /-amino-effect reactions yielding benzimidazoles, and featured significantly in the previous review. Further work on transformation of the cobalt(II) complex of 2-dimethylaminoazo-benzenes to Y-methylbenzimidazole has shown that the azo compound converts ethanol to acetaldehyde [and cobalt(III) is formed] during the process [77JCS(D)872]. In a related manner, Kirschke (86TL4281) observed that attempts to recrystallize the azo compound 38 from ethyl acetate resulted in its conversion into the benzimidazole 40, as shown in Scheme 14. When ethanol was used, the intermediate 39 was isolable. 

NOCgHj, Benzoyl isocyanide, chromium complex, 26 32,34,35 N0C,3H,3, Formanide, N-(l-(l-naphthal-enyl)ethyll-, rhenium complex, 29 217 NOPCjsHjj, Benzamide. 2-(diphenylphos-phino)-N-phenyl-, 27 324 NOPCjjHjj, Benzamide, Af-[2-(diphenyl-phosphino)phenyl]-, 27 323 NO2CH3, Methane, nitro-, antimony complex, 29 113 cobalt complex, 29 114 NOjCjHj, 4-Pyridinecarboxylic acid, rhodium complex, 27 292 NO2P2C3JH33, Phosphorus(l-t-), p-nitrido-bis(triphenyl-, acetate, 27 296 NO2SC3H7, L-Cysteine, molybdenum complex, 29 255,258... 

C8H16CI6CU3O4, Copper(II) chloride - 1,4-dioxan (3 2), 43B, 1353 C8H16Cl804Ti2, Titanium(IV) chloride-ethyl acetate complex, 31B, 442 C8H16N2O10U, Uranyl nitrate - bis(tetrahydrofuran), 43B, 1283 CbHi8CI2C0N2O2 f Dichlorobis(N,N-dimethylacetamide)cobalt(II), 39B, 765... 

Reaction of electron-rich olefins such as vinyl ethers have not enabled us to observe spectroscopically a complex with cobalt(III) cobaloximes. Nevertheless, the reaction between a cobal(III)oxime, ethyl-vinyl ether, and ethanol gives complete alkylation of the cobalt (33). When the ethanol is not vigorously anhydrous, some formyl-methylcobaloxime (25) (Scheme 7) is formed also and these observations are consistent (34) with the reactions outlined in Scheme 7. When the water concentration was increased, the amount of formylmethyl-cobaloxime also increased at the expense of the acetal. Thus, we anticipated that the analogous reaction with vitamin Bi2, which is impossible to obtain in an anhydrous condition and is best manipulated in... 

Several efficient oxidation reactions with molecular oxygen were developed using transition-metal complexes coordinated by variuos ligands in combination with apprOTriate reductants. Recently, it was found that cyclic ketones such as 2-methylcyclohexanone and acetals of aldehyde such as propionaldehyde diethyl acetal were effectively employed in aerobic epoxidation of olefins catalyzed by cobalt(II) complexes. In the latter case, ethyl propionate and ethanol were just detected in nearly stoichiometric manner as coproducts (Scheme 12), therefore the reaction system is kept under neutral conditions during the epoxidation. 

---