Showing papers on "Copper published in 1974"

Catalyst for electroless deposition of metals

Abstract: A solvent method for the metallization of a non-conductive surface with gold, nickel or copper is shown whereby on a substrate a thermosensitive coordination complex of palladium is deposited; the complex has the formula LmPdXn wherein L is a ligand or unsaturated organic radical, X is a halide, alkyl group or a bidentate ligand and m is an integer from 1 to 4 and n is from 0 to 3; trimethyl phosphite palladium dichloride complex is an appropriate illustration of the complex; the palladium complex is applied on the substrate in a suitable non-aqueous solution such as tetrahydrofuran solution; the complex is then baked in air at elevated temperature; the exposure to high temperature decomposes the complex leaving a residue which is catalytic to the deposition of gold, nickel, cobalt or copper from an electroless bath thereof; the non-conductive material is then immersed in an electroless bath to metallize the areas which have been rendered catalytic; the preferred thermosensitive coordination complex of palladium is trimethyl phosphite palladium dichloride; a requirement for a proper thermal exposure of the complex is that the substrate is capable of withstanding the elevated temperatures such as above 210°C; illustrative organic substrates are polyimides, polysulfones, silicones, vulcanizates, fluoroplastics, polyphenylene sulfides, polyparabanic acids, and polyhydantoin, etc.

Effect of Complexation on Toxicity of Copper to Fishes

Abstract: Copper (Cu) is highly complexed by carbonate and hydroxide ions in natural waters and this complexation determines the concentration of copper species in solution. Results of detailed equilibrium calculations on data from bioassays where alkalinity, pH, hardness, and total copper concentration are different indicate that copper(II) is the chemical species that is toxic to fishes and that alkalinity is the factor controlling copper(II) concentration.

Copper(I) alkoxides. Synthesis, reactions, and thermal decompositions

Abstract: Alkoxides and phenoxides of copper(I) can be prepared by the heterogencous reaction between alcohols and phenols and methylcopper(I). These organocopper(I) compounds are useful reagents for the formation of ethers by displacement of hai ide from organic hal ides. The reaction of copper(l) alkoxidcs with aryl hal ides yields alkyl aryl ethers under part icularly mild iondit ions. Thermal decomposit ion of primary alkorycopper(l) reagcnts generates intermediate alkoxy radicals. Thermal clecomposit ion of secondary alkoxycopper(l) reagents apparently can take place either by a free-radical mechanism or by a mechanism tentat ively suggested to involve copper(I)-hydride as an intermediate. The structural factors determining which mechanism wil l predominate for a given compound have not been established' tTth. utit i ty of alkyland arylcopper(l) reagents in I organic synthesis is based on their h igh nucleophi l ic i ty toward carbon, and on their abi l i ty to take part in electron-transfer reactions.2-a They also show low basicity toward protons, an afff inity for carboncarbon double bonds, and an abi l i ty to coordinate wi th soft Lewis bases. Since the mechanisms by which copper(I) influences the reactivity of carbanions are not clearly understood, it is diff icult to predict the behavior of new types of organocopper( I ) compounds. Nevertheless, there is obvious reason to hope that organic derivatives of copper(I) other than those belonging to the wel l -explored class of compounds containing carbon-copper bonds might also show useful (1) Supported by the Nat ional Science Foundat ior l , Grants GP28586X ancl GP-14247, ancl by the Internat ional coppcr Rcsearch Associat ion. (2) J. F. Normant, S) 'nthesis,2,63 (1972); G' H. Posner, Org' React ' , 19, | (1972), (3) G. Br ihr ancl P. Burba in \"Methoden der organischen chemie\" (Houben-Weyl) , Vol . XI I I /1, E ' Mi , i l ler , Ed. , Georg Thicme Vcr lag, Stut tgart , 1970, p 731 f f . (4) O. A. Chal tyk ian, \"Copper-Catalyt ic React ions,\" A. E. Stubbs, t rans. , Consul tants Bureau, New York, N' Y. , 1966; P. F. Fanta, Chem. Rec, ,64,613 (1964); R. G. R. Bacon and H. A. O. Hi l l ' Quart ' Rec. , Chem. Soc. , 19,95 (1965); J. Peisach, P. Aisen, and W. E' Blurnberg, Ed., \"The Biochemistry of Copper,\" Academic Press, New York, N . Y . . 1966 . react iv i ty. This paper descr ibes studies of one such class: a lkoxides of copper( l ) . These studies had three object i ies: synthesis and character izat ion of a lkoxides und phenox ides o f copper ( l ) ; de termina t ion o f the behar l ior of thesc substances in react ions whose usefulness with alkylcopper reagents has already been establ ished: and examinat ion of the mechanisms of their thermal decomposi t ion. Copper( l ) a lkoxides and phenoxides have been impl icated previously as intermediates in a var iety of copper-catalyzed react ions,a '5 and poor ly character ized examples of these substances have been prepared'6 A useful synthesis of copper([) tert-butoxideT is not appl icable to the preparat ion of the thermal ly unstable copper( I ) pr imary and secondary alkoxides that were of ^central interest in our work. The preparat ion of copper( I ) phenoxide by a procedure analogous to that descr ibed here has been reported.s Copper( I ) a lkoxides (5) J. K. I (ochi , Proc. I t t t . Congr. Pure Appl ' Chem', 23rd,4 ' 377 (1971), and referenccs citcd therein, (6 ) b . E . H . Bawr r and F . J . Wh i tbv , J . Chem.9oc . ,3926 (1960) ; G ' Costa. A. Camus, and N. Marsich, J. Inorg ' l ' ' luc l ' Chem',27' 281 ( I e6s ) . (7) T. Saegusa, T. Tsucla, and T. Hashirnoto, J ' Amer ' Chem' Soc\" 94 ,658 (1972) . iSl f. I(awaki and H. Hashimoto, Bull. Chem. Soc' Jap', 45, 1499 (r972). Whitesides, et al, I St'nthesis ttf Cttpper(l) Alkoxides

Composition and Stability of Iron and Copper Citrate Complexes in Aqueous Solution

Abstract: The acidity constants of citric acid and the stability constants of the citrate complexes of copper(II), iron(II), and iron(III) have been measured at 25 °C in 0.1 M KNO3 background. The measuremen...

The thermal decomposition of calcium, sodium, silver and copper(II) acetates

Abstract: The thermal decomposition of the acetates of calcium, sodium, silver and copper(II) have been investigated using thermogravimetry and differential thermal analysis, together with analysis of the gaseous products formed during the decomposition process. The results indicate that the major organic product formed is either acetone or acetic acid, depending on whether the final solid product is the oxide or the metal.

A kinetic theory of atomisation for non-flame atomic-absorption spectrometry with a graphite furnace. The kinetics and mechanism of atomisation for copper

Abstract: A kinetic approach has been made to the atomisation process in nonflame atomic-absorption spectrometry. Time-absorbance profiles for the determination of copper, using a graphite furnace, have been investigated in the temperature range 1720 to 2220 K and a rate equation derived that describes the variation of the amount of copper atoms in the furnace with time. It has been shown that a slow first-order reaction involving reduction of copper oxide by carbon followed by the rapid vaporisation of the copper formed is the most probable reaction mechanism. The greater sensitivity achieved in the determination of copper using a tantalum-lined graphite furnace has been attributed in part to the greater rate of reduction of copper oxide by tantalum.

Cohesion margin of copper

Abstract: Measurements on the mechanical properties of copper-bismuth alloys show that the only effect of bismuth within the solid solution range is to reduce the true tensile strength of the alloys—there is no detectable effect on plastic behaviour or on the elastic limit. Intergranular fracture occurs by the formation of grain boundary crack nuclei, these being seen in alloys containing as little as 0·002 wt.-% Bi. In addition, by measuring the effect of bismuth on surface and grain boundary energies of copper, it is shown that bismuth is present at the grain boundaries at monolayer levels, as true Gibbs segregation. It appears that the brittleness is due simply to reduced grain boundary cohesion. The measured relative cohesion of the copper-bismuth alloy is approximately half that of pure copper: such a reduction in grain boundary cohesion therefore converts ductile copper into a brittle metal, and thus defines a margin of cohesion. Reduced grain boundary cohesion favours the nucleation of cracks where ...

Diffusion in Copper and Copper Alloys, Part II. Copper‐Silver and Copper‐Gold Systems

Abstract: A survey, comparison, and critical analysis is presented of data compiled from the scientific literature concerning diffusion in copper‐silver and copper‐gold systems. Here the term ``copper alloy system'' is interpreted in the broadest sense. For example, the review of diffusion in the Cu‐M system reports all diffusion situations which involve both copper and element M, including diffusion of Cu in M or in any binary, ternary, or multicomponent alloy containing M: diffusion of M in Cu or in any alloy containing Cu; and diffusion of any element in any alloy containing both Cu and M. Topics include volume diffusion, surface diffusion, grain boundary diffusion, tracer diffusion, alloy interdiffusion, electromigration, thermomigration, strain enhanced diffusion, and diffusion in molten metals. An extensive bibliography is presented along with figures, tabular presentation of data and discussion of results.

Metal loss to slag: Part I. Sulfidic and oxidic dissolution of copper in fayalite slag from low grade matte

Abstract: An experimental technique to prepare slags free from suspended matte was developed and applied to measure the solubility of copper in Fe- and SiO2-saturated fayalite slag at 1200°C. The copper solubility was found to be considerably greater than that attributed to oxidic loss assessed from the work of Ruddleet al and also greater than that in previously-studied slags containing sulfur together with lime or alumina. The solubility was related to the presence of sulfur in the slag, and the concept of sulfidic dissolution was developed on the basis of thermodynamic properties of matte and slag. The model was applied to commercial slag-matte systems, and the reduction of sulfur solubility by changing the slag composition was concluded to be the key in reducing copper losses to slag, especially for mattes containing less than 50 pct Cu.

Electrodeposition of copper

Abstract: B. sulfoalkyl sulfide compounds containing the grouping --S--Alk--SO3 M where M is one gram-equivalent of a cation and --Alk-- is a divalent aliphatic hydrocarbon group of 1 to 8 carbon atoms.