Ethanol, 2- -, copper complex

Copper complexes can act as bidentate ligands towards transition metal ions.912,913 On mixin a solution of CuHAPen in CHC13 (CuHAPen = JV,AP-ethylenebis(o-hydroxyacetophenonf iminato)copper(II)) with an ethanol solution of VO(C104), a precipitate formed. Afte recrystallization from nitroethane the compound [V0(CuHAPen)2](C104)2-3H20-iEtNC... 

Ethanol was used, for example, in preparation of zinc complex of 2-hydroxy-1-(N-phenylaminomethyl) 673 [246] and copper complexes of hydrazoneimines of the type 674 [247], whose structures were determined by x-ray diffraction. The complexes of salicylidenthiocarbonylhydrazones of the type 675-677 were synthesized in the same solvent [248]. The complexes 675 are formed from metal acetates [Cu(II)], 676 from nitrates [Ni(II)], and 677 from chlorides [Fe(III)] ... 

Tetrakis(L)copper(I) or Silver (I) Perchlorate prom Isomers A AND B. To a suspension of 0.7 g. (4 mmoles) of isomer A or B in 25 ml. of acetone was added 1 mmole of copper(II) perchlorate hexahydrate or anhydrous silver(I) perchlorate, and the suspension was stirred for 18 hrs. The colorless copper complex was filtered off and dried under vacuum at room temperature. Some reduction to silver metal occurred in the reaction of silver perchlorate. The precipitate was therefore extracted with ethanol, and the extract was filtered and concentrated to obtain the complex. Approximately 30% yields of both compounds were obtained. 

An equimolar mixture of the Schiff base and cupric acetate monohydrate in ethanol was heated under reflux for 2 h. The ethanol was evaporated in vacuo and the dark green residue was dissolved in toluene. The toluene solution was treated with aqueous sodium hydroxide to complete complex formation. Removal of the toluene followed by trituration in methanol induced crystallization of the copper complex as a bluish green mass. Filtration of the solid followed by drying in vacuo gave a pure sample, [a]546 -1-1040 ° (c 0.087, benzene), mp 186-188 °C (dec), in 77% yield based on the Schiff base. The magnetic susceptibility i was 0,86 B.M. For X-ray crystallography, see [14]. 

Bis- and tris(hexafluoro-2,4-pentanedionato) (hexafluoroacetyl-acetonate, hfa) complexes of 23 different metal(II), (III), and (IV) ions have been prepared.1 5 Most of these have been isolated as low-melting solids, which can be readily sublimed unchanged between 25 and 150°. Most methods of synthesis of this class of complexes in different solvents have resulted in incomplete conversion to the chelate. For example, the copper complex Cu(hfa)2 has been prepared in 80% yield using excess ligand as the solvent. Several solvents having various polarities (water, ethanol, carbon tetrachloride, acetone) have been used. 

Red-violet modification. A mixture of 2.05 g. (0.008 mol) of phenylbiguanide-p-sulfonic acid and 150 ml. of water is acidified with 1.5 ml. of concentrated hydrochloric acid (35%) and warmed to 60°. To this solution is added 1 g. (0.004 mol) of copper (II) sulfate 5-hydrate dissolved in 10 ml. of water. The resulting solution is then treated with dilute (12%) ammonia water drop by drop imtil the solution becomes just alkaline and the red-violet crystals of the copper complex separate. About 4 ml. of ammonia is required. The crystals are filtered, washed first with 100 ml. of water and finally with 15 ml. of ethanol, and dried in air. Yield 2.2 g. (93% based on copper taken). Anul. Calcd. for [Cu(H03SC6H4C2NsH5)2]-H20 N, 23.59 Cu, 10.71 H2O, 3.04. Found N, 23.66 Cu, 10.61, 10.64 H2O (loss at 90°), 3.0. 

Ethanol, benzyl alcohol or 2-butanol coordinate to the proposed dinuclear copper complex (Fig. 16) to produce the active species I (Fig. 17, A). After H abstraction by one of the two phenoxyl groups, a radical is created which is oxidized to the corresponding carbonyl derivative by the second phenoxyl radical. In the case of 2-propanol and diphenylmethanol, two alcohol molecules coordinate to the dinuclear moiety resulting in species II (Fig. 17, B). The H abstractions by the two phenoxyl ligands generate two... 

Xu et al. [52] described an extraction of copper and cadmium from urine and digested tissue samples as the diethyldithiocarbamate (DDTC) complexes on reversed phase Cjg immobilized on silica gel and elution into FAAS by ethanol. Copper could be determined in all the samples with good sensitivity and accuracy. Cadmium in urine could also be determined without problems, and the detection limit was around 0.2 jig/liter with only 35 sec preconcentration, resulting in a sampling frequency of 85 per hour. However, in some tissue samples, such as liver, the values for cadmium were up to 50% low because of an interference by copper, as mentioned previously. 

The reaction of thioureas with nucleophiles has been only sparsely studied in the past. Guanidines have been prepared by treatment of corresponding thioureas with propylamine in the presence of lead oxide, and thioureas with a hydroxy-group at the / -position of the N-substituent have been cyclized to oxazolines by refluxing in ethanol in the presence of cupric acetate. The latter reaction was shown to proceed via an intermediate copper complex. ... 

When dap reacts with an aromatic 3,3-triamine in the presence of nickel(II), copper(II) or cobalt(II) perchlorate in ethanol, macrocyclic complexes with tetra-dentate ligands [M(L712)](C104)2 and having octahedral structures are isolated (Eq. 3.35) [73]. 

The integrated balance of oxidation and reduction which this process makes possible cannot always be achieved. Yet the recycling of the cofactor is obviously crucial. A second, quite separate reaction can be introduced, for example the oxidation of ethanol to acetaldehyde with an alcohol dehydrogenase. However there is some hope that an electrolytic reduction of the NAD could be developed. This is illustrated by the manufacture of glutathione which is an important thiol-containing peptide. The dimeric disulphide is isolated from yeast cells as a copper complex. This is treated with sulphide to remove the copper, and the free peptide is then reduced at acid pH in the catholyte of an electrolytic half cell. The oxidation of the thiol at the anode is prevented by an ionic membrane which separates the two halves of the cell. 

A 10%-soln. of pentane-2,4-dione copper complex in chloroform shaken 12-24 hrs. at room temp, with a 10%-soln. of m-nitrobenzoyl chloride in the same solvent, and the crude intermediate triketone heated 10-15 min. with aq. 3 N NHg l-m-nitrophenylbutane-l,3-dione. Y 92%.—The method is simple, gives good yields of pure products, and is the most convenient one for the prepn. of certain / -diketones. F. e., also deacetylation of the triketones with ethanolic 30%-H2S04, and condensations with ethyl acetoacetate copper complex, s. W. J. Barry, Soc. 1960, 670. 

Schemes 58-62. A new non-rigid phosphine ligand was synthesized and reacted with Fe(CO)5 to form the mononuclear iron complex (Equation (81)). Phosphino-oxazoline ligands were used as assembling ligands for hetero-metallic complexes, where the phosphorus atom binds to iron and the nitrogen atoms act as donor atoms to copper, cobalt, or palladium (Scheme 58). The copper complex catalyzes cyclopropanation and Diels-Alder reactions. When 2-(A -diphenylphosphinomethyl-A -cyclohexyl)aminopyridine (NNP) reacts with Fe(CO)5 in ethanol, /ra .r-(OC)3Fe(NNP)2 is formed (Scheme 59). This monometallic complex can then be reacted with a copper salt in CH2GI2 to form a complex having an Fe-Cu dative bond. The complex was demonstrated to be an efficient catalyst for the cyclopropanation of styrene by ethyl diazoacetate and for the Diels-Alder reaction of cyclopentadiene and methacrolein. No other heterometallic complexes have been shown to have such reactivity. Previously known...

Prepare the nitrate of the copper complex as in Sec. 17.6.1. Dissolve 2.7 g mercury(II) chloride in 35 cm and add to the solution 3.3 g KI and 3.4 g NH4 SCN. After dissolving the solids, add 15 cm ethanol and carefully bring to the boil on an electric water bath. Using the copper complex prepared as above (Sec. 17.6.1), add the concentrated solution to the mercury complex solution with vigorous stirring until precipitation seems complete. Cool in an ice/water bath to complete the precipitation and continue as in 17.6.1. 

Mixed 6),Af-donor ligands such as Schiff bases are of interest in that they provide examples not only of square-planar coordination but also, in the solid state, examples of square-pyramidal coordination by dimerization (Fig. 28.6(b)). A similar situation occurs in the bis-dimethylglyoximato complex, which dimerizes by sharing oxygen atoms, though the 4 coplanar donor atoms are all nitrogen atoms. Copper(II) carboxylates are easily obtained by crystallization from aqueous solution or, in the case of the higher carboxylates, by precipitation with the appropriate acid from ethanolic solutions... 

Procedure. To 10.0 mL of the solution containing up to 200 fig of copper in a separatory funnel, add 5.0 mL of 10 per cent hydroxylammonium chloride solution to reduce Cu(II) to Cu(I), and 10 mL of a 30 per cent sodium citrate solution to complex any other metals which may be present. Add ammonia solution until the pH is about 4 (Congo red paper), followed by lOmL of a 0.1 per cent solution of neo-cuproin in absolute ethanol. Shake for about 30 seconds with 10 mL of chloroform and allow the layers to separate. Repeat the extraction with a further 5 mL of chloroform. Measure the absorbance at 457 nm against a blank on the reagents which have been treated similarly to the sample. 

The precipitate is soluble in free mineral acids (even as little as is liberated by reaction in neutral solution), in solutions containing more than 50 per cent of ethanol by volume, in hot water (0.6 mg per 100 mL), and in concentrated ammoniacal solutions of cobalt salts, but is insoluble in dilute ammonia solution, in solutions of ammonium salts, and in dilute acetic (ethanoic) acid-sodium acetate solutions. Large amounts of aqueous ammonia and of cobalt, zinc, or copper retard the precipitation extra reagent must be added, for these elements consume dimethylglyoxime to form various soluble compounds. Better results are obtained in the presence of cobalt, manganese, or zinc by adding sodium or ammonium acetate to precipitate the complex iron(III), aluminium, and chromium(III) must, however, be absent. 

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