Potassium acetate complex with

Potassium acetate complex with dicyclohexyl-18-crown-6-polyether, 52, 71 Potassium amide, 52, 75 Potassium azide, 50, 10 Potassium tert-butoxide, 52,... 

Replacement of silver nitrite by inexpensive sodium or potassium nitrite enhances the utility of this process. Treatment of alkenes with sodium nitrite and iodine in ethyl acetate and water in the presence of ethylene glycol gives conjugated nitroalkenes in 49-82% yield.63 The method for generation of nitryl iodide is improved by the treatment of iodine with potassium nitrite complexed with 18-crown-6 in THF under sonication, as shown in Eq. 2.32s4... 

The work of Hyatt on cyclotriveratrylene—derived octopus molecules contrasts with this. Of course, these species have the advantage of ligand directionality absent in the benzene-derived octopus molecules. Except for the shortest-armed of the species (i.e., n = 1), all of the complexing agents (i.e., n = 2—4) were capable of complexing alkali metal cations. Synthesis of these species was accomplished as indicated below in Eq. (7.7). These variations of the original octopus molecules were also shown to catalyze the reaction between benzyl chloride and potassium acetate in acetonitrile solution and to effect the Wittig reaction between benzaldehyde and benzyltriphenylphos-phonium chloride. 

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. 

The cobalt complex is usually formed in a hot acetate-acetic acid medium. After the formation of the cobalt colour, hydrochloric acid or nitric acid is added to decompose the complexes of most of the other heavy metals present. Iron, copper, cerium(IV), chromium(III and VI), nickel, vanadyl vanadium, and copper interfere when present in appreciable quantities. Excess of the reagent minimises the interference of iron(II) iron(III) can be removed by diethyl ether extraction from a hydrochloric acid solution. Most of the interferences can be eliminated by treatment with potassium bromate, followed by the addition of an alkali fluoride. Cobalt may also be isolated by dithizone extraction from a basic medium after copper has been removed (if necessary) from acidic solution. An alumina column may also be used to adsorb the cobalt nitroso-R-chelate anion in the presence of perchloric acid, the other elements are eluted with warm 1M nitric acid, and finally the cobalt complex with 1M sulphuric acid, and the absorbance measured at 500 nm. 

Pd-catalyzed asymmetric allylic alkylation is a typical catalytic carbon-carbon bond forming reaction [ 126 -128]. The Pd-complex of the ligand (R)-3b bearing methyl, 2-biphenyl and cyclohexyl groups as the three substituents attached to the P-chirogenic phosphorus atom was found to be in situ an efficient catalyst in the asymmetric allylic alkylation of l-acetoxy-l,3-diphenylprop-2-en (4) with malonate derivatives in the presence of AT,0-bis(trimethylsilyl)acetamide (BSA) and potassium acetate, affording enantioselectivity up to 96% and quantitative... 

The checkers prepared a crystalline complex of potassium acetate with isomer B of dicyclohexyl-18-crown-6 polyether by the following procedure. To a stirred solution of 15.0 g. (0.0404 mole) of dicyclohexyl-18-crown-6 polyether (mixture of isomers) in 50 ml. of methanol was added a solution of 5.88 g. (0.0600 mole) of anhydrous potassium acetate (dried at 100° under reduced pressure) in 35 ml. of methanol. The resulting solution was concentrated under reduced pressure with a rotary evaporator, and the residual white solid was extracted with 35 ml. of boiling methylene chloride. The resulting mixture was filtered and the filtrate was cooled in a dry ice-acetone bath and slowly diluted with petroleum ether (b.p. 30-60°, approximately 200 ml. was required) to initiate crystallization. The... 

The potentially terdentate ligand, thiodiethanol (88), forms 1 1 complexes and 1 2 complexes with C0CI2. The former are five-co-ordinate and the latter octahedral. 1 1 Complexes of Co and diethylenetrithioacetic acid, ethylene-dithiodiacetic acid, and ethylidenetetrathiotetra-acetic acid have all been reported." " Potassium monothiobenzoate reacts with an equimolar quantity of CoSO in aqueous solution to yield green crystals of the pseudo-tetrahedral dinuclear complex [Co2(SOCPh)4 ], which contains both bidentate and bridging thiobenzoate ligands. ... 

The related dirhodium(II) a-caprolactamate (cap) complex [Rh2(p--cap)4] undergoes a one-electron oxidation process at quite a lower potential (11 mV) than the acetate complex (1170 mV). In agreement with the Kochi hypothesis, the a-caprolactamate complex has recently been found to be an exceptional catalyst for the allylic oxidation of alkenes under mild conditions. A wide range of cyclohexenes, cycloheptenes, and 2-cycloheptenone (Eq. 5) are rapidly converted to enones and enediones in 1 h with only 0.1 mol % of [Rh2( x-cap)4] and yields ranging from 60 to 90%, in the presence of potassium carbonate [34]. 

The C-enriched hexacyanochromate(III), K3[Cr( CN)g], is obtained by following a similar synthetic route. When 0.230 g of chromous(II) acetate complex is used in the reaction with 1 g of C-enriched potassium cyanide, then 0.198 g... 

Since the first X-ray analysis of the complex of a-cyclodextrin with potassium acetate was reported by Hyble et al. (8), the various types of cyclodextrin complexes have been studied by X-ray crystallography as shown in Table I. In contrast with cyclodextrin, only two examples of X-ray analyses of cyclo-phanes as inclusion hosts are known, which are also shown in Table I. 

Amines (am) react with these bridged complexes to give mononuclear complexes of the type [RhX(am)(diene)] a similar complex is formed by triphenylphosphine, but not by triphenylarsine or diphenylsulphide. Cationic and anionic complexes of the type [Rh(diamine) (diene)]+ and [RhCl2(diene)] are readily formed. The stable acetate (XXVII X = OAc) is prepared from the corresponding chloride and potassium acetate its infrared spectrum indicates that each acetate group is symmetrically bound... 

Reduction of the complex on Raney nickel yielded benzylamine, N-methyl-benzylamine, and N,N-dimethylbenzylamine but no / -phenylbenzylamine, a reduction product resulting under the same reaction conditions from benzyl cyanide. Hydrolysis with dilute sulfuric acid in acetic acid yielded benzylamine only, and oxidation of the complex with potassium permanganate gave 4.2 moles of benzoic acid per mole of complex. The bromide anion can be exchanged metathetically with various other anions such as perchlorate, iodide, and thiocyanate. When heated at 100° C. in vacuum, the complex lost one mole of benzyl bromide and yielded only one dicyanotetrakis(benzylisonitrile)iron(II) complex. 

A preparative solid- gas phase synthesis of acetyl hypofluorite (1, R = Me) has been described it is based on the reaction of dilute fluorine (with air or nitrogen) with a solid complex of potassium acetate with acetic acid and can be also modified7 -9 for the preparation of acetyl... 

Other physical phenomena that may be associated, at least partially, with complex formation are the effect of a salt on the viscosity of aqueous solutions of a sugar and the effect of carbohydrates on the electrical conductivity of aqueous solutions of electrolytes. Measurements have been made of the increase in viscosity of aqueous sucrose solutions caused by the presence of potassium acetate, potassium chloride, potassium oxalate, and the potassium and calcium salt of 5-oxo-2-pyrrolidinecarboxylic acid.81 Potassium acetate has a greater effect than potassium chloride, and calcium ion is more effective than potassium ion. Conductivities of 0.01-0.05 N aqueous solutions of potassium chloride, sodium chloride, potassium sulfate, sodium sulfate, sodium carbonate, potassium bicarbonate, potassium hydroxide, and sodium hydroxide, ammonium hydroxide, and calcium sulfate, in both the presence and absence of sucrose, have been determined by Selix.88 At a sucrose concentration of 15° Brix (15.9 g. of sucrose/100 ml. of solution), an increase of 1° Brix in sucrose causes a 4% decrease in conductivity. Landt and Bodea88 studied dilute aqueous solutions of potassium chloride, sodium chloride, barium chloride, and tetra-... 

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