Copper aqueous chemistry

An even more serious problem can arise when dissolved species expected to predominate at high temperatures are undetectable at 25°C or are only present at concentrations which are too low for them to be adequately characterized thermodynamically. Examples are certain transition metal chloro-complexes (9,10) and mixed complexes of such metals with hydroxide and another ligand (11,12). Thus it seems that chloride complexing so alters the aqueous chemistry of copper and gold that supposedly inert gold components in autoclaves are reversibly oxidized by Cull (10) and it is likely that mixed oxine and hydroxy complexes of Fell contribute considerably to the gross under-estimation (by a factor of up to 10 ) of magnetite solubility in oxine (12,14). 

Fluoroalkyl copper compounds, 17 143, 144 a-Fluoroalkylidinehydrazines, 33 167 2-Fluoroalky 1 -2 phospha-1,3-dialky 1 -1,3-diaze-tidinones, synthesis of, 14 87 Fluoroanions, trivalent, uranium, 34 94—95 Fluoroantimony compounds, 7 17 Huoroaryl copper compounds, 17 143, 144 Fluoroberyllates anhydrous, 14 267-276 aqueous chemistry of, 14 274-278 glasses, 14 265-267 preparation and properties of, 14 265-267... 

The Cupric, Cu2+ or Cu(II) State, 3d9 The most important and stable oxidation state for copper is divalent. There is a well-defined aqueous chemistry of the Cu2+ ion, which generates the familiar blue solution when complexed with water. A large number of copper coordination compounds exist and these have been studied extensively. A strong Jahn-Teller distortion is associated with the 3d9 electronic configuration of this ion. This implies that a regular tetrahedron or octahedron about the Cu2+ ion is never observed, except in the rare occurrence of a dynamic Jahn-Teller effect. The tetragonal distortion about an octahedron can lead to a square-planar coordination which is often observed in Cu(II) oxides. 

A side-on p,-Tq2 Tq2-peroxo dicopper(II) complex. A very important development in copper-dioxygen chemistry occurred in 1989 with the report by Kitajima et al. [10,108] that another Cu202 species could be prepared and structurally characterized by using copper complexes with a substituted anionic tris(pyrazolyl)borate ligand. This intensely purple compound, Cu[HB(3,5-iPr2pz)3] 2(02) (5), was prepared either by reaction of Cu[HB(3,5-iPr2pz)3] (4) with 02 or by careful addition of aqueous hydrogen peroxide to the p-dihydroxo... 

We discuss in this chapter the elements of the first transition series, titanium through copper. There are two main reasons for considering these elements apart from their heavier congeners of the second and third transition series (1) in each group (e.g., V, Nb, and Ta) the first-series element always differs appreciably from the heavier elements, and comparisons are of limited use, and (2) the aqueous chemistry of the first-series elements is much simpler, and the use of ligand field theory in explaining both the spectra and magnetic properties of compounds has been far more extensive. 

The dipositive state is the most important one for copper. Most cuprous compounds are fairly readily oxidized to cupric compounds, but further oxidation to Cu111 is difficult. There is a well-defined aqueous chemistry of Cu2+, and a large number of salts of various anions, many of which are water-soluble, exist in addition to a wealth of complexes. 

Chatteijee A, Das D, Mandal BK, Chowdhury TR, Samanta G, Chakraborti D (1995) Arsenic in groundwater in six districts of West Bengal, India The biggest arsenic calamity in the world. Part I. Arsenic species in drinking water and urine of affected people. Analyst 120 643-650 Cheah S-F, Brown GE Jr, Parks GA (1997) The effect of substrate type and 2,2 -bipyridine on the sorption of copper(II) on silica and alumina. In Voigt JA, Bunker BC, Casey W, Wood , Crossey LJ (eds) Aqueous Chemistry and Geochemistry of Oxides, Oxyhydroxides, and Related Materials, Mat Res Soc SympProc 432 231-236... 

Although most of the aqueous chemistry of copper involves the +2 oxidation state, there are a number of important compounds of coppeifl). When copper is heated in oxygen below 1000°C, it forms the black copper(II) oxide, CuO. But above this temperature, it forms the brick-red copper(I) oxide, CU2O. This oxide is found naturally as the mineral cuprite. 

J. Tidblad and T. E. Graedel, GILDES model studies of aqueous chemistry III. Initial S02-induced atmospheric corrosion of copper, Corros. Sci. 55 2201 (1996). J. Tidblad and T. E. Graedel, GILDES model studies of aqueous chemistry V. Initial SOj-induced atmospheric corrosion of nickel, J. Electrochem. Soc. 744 2676 (1997). 

J. Tidblad and T. E. Graedel, GILDES model studies of aqueous chemistry ill. initial SOj-induced atmospheric corrosion of copper, Corros. Sci. 38 2201 (1996). 

Arsonium salts have found considerable use in analytical chemistry. One such use involves the extraction of a metal complex in aqueous solution with tetraphenyiarsonium chloride in an organic solvent. Titanium(IV) thiocyanate [35787-79-2] (157) and copper(II) thiocyanate [15192-76-4] (158) in hydrochloric acid solution have been extracted using tetraphenyiarsonium chloride in chloroform solution in this manner, and the Ti(IV) and Cu(II) thiocyanates deterrnined spectrophotometricaHy. Cobalt, palladium, tungsten, niobium, and molybdenum have been deterrnined in a similar manner. In addition to their use for the deterrnination of metals, anions such as perchlorate and perrhenate have been deterrnined as arsonium salts. Tetraphenyiarsonium permanganate is the only known insoluble salt of this anion. 

Some electrodes are made of substances that participate in the redox reactions that transfer electrons. These are active electrodes. Other electrodes serve only to supply or accept electrons but are not part of the redox chemistry these are passive electrodes. In Figure 19-7. both metal strips are active electrodes. During the redox reaction, zinc metal dissolves from the anode while copper metal precipitates at the cathode. The reactions that take place at these active electrodes are conversions between the metals contained in the electrodes and their aqueous cations. 

Hirano, K., Inoue, K., and Yatsu, T. (1992) Photocatalysed reduction of C02 in aqueous Ti02 suspension mixed with copper powder. Journal of Photochemistry and Photobiology A Chemistry, 64 (2), 255-258. Adachi, K., Ohta, K., and Mizuno, T. (1994) Photocatalytic reduction of carbon dioxide to hydrocarbon using copper-loaded titanium dioxide. Solar Energy,... 

Fotovat A., Naidu R., Sumner M.E. Water Soil ratio influences aqueous phase chemistry of indigenous copper and zinc in soils. Aust J Soil Res 1997 35 687-710. 

Leckie, J.O. and J.A. Davis. 1979. Aqueous environmental chemistry of copper. Pages 89-121 in J.O. Nriagu (ed.). Copper in the Environment. Part 1 Ecological Cycling. John Wiley, NY. 

Initial studies, described here, involved the use of an ultrahigh vacuum (UHV) surface-analytical instrument coupled to an antechamber. The antechamber allows experiments in solution and electrochemical treatments without transfer of samples outside of the system s controlled atmosphere. Focusing on the chemistry of copper surfaces in aqueous environments suggests the importance of studying the initial stages of surface reactivity with oxygen and water. Electrochemical experiments involve electrolytes thus their surface reactivity should be studied as well. 

Doe BR (1994) Zinc, copper, and lead in mid-ocean ridge basalts and the source rock control on Zn/Pb in ocean-ridge hydrothermal deposits. Geochim Cosmochim Acta 58 2215-2223 Ehrlich S, Butler I, Halicz L, Rickard D, Oldroyd A, Matthews A (submitted) Experimental study of copper isotope fractionation between aqueous Cu(II) and covellite, CuS. Chem Geol Finney LA, O Halloran TV (2003) Transition metal speciation in the cell insights from the chemistry of metal ion receptors. Science 300 931-936... 

Immobilizing DENs within a sol-gel matrix is another potential method for preparing new supported catalysts. PAMAM and PPI dendrimers can be added to sol-gel preparations of silicas " and zinc arsenates to template mesopores. In one early report, the dendrimer bound Cu + ions were added to sol-gel silica and calcined to yield supported copper oxide nanoparticles. Sol-gel chemistry can also be used to prepare titania supported Pd, Au, and Pd-Au nanoparticle catalysts. Aqueous solutions of Pd and Au DENs were added to titanium isopropoxide to coprecipitate the DENs with Ti02. Activation at 500°C resulted in particles approximately 4 nm in diameter. In this preparation, the PAMAM dendrimers served two roles, templating both nanoparticles and the pores of the titania support. 

In your previous chemistry course, you compared the reactivities of metals. You may recall that, when a piece of zinc is placed in an aqueous solution of copper(II) sulfate, the zinc displaces the copper in a single displacement reaction. This reaction is shown in Figure 10.1. As the zinc dissolves, the zinc strip gets smaller. A dark red-brown layer of solid copper forms on the zinc strip, and some copper is deposited on the bottom of the beaker. The blue colour of the solution fades, as blue copper(ll) ions are replaced by colourless zinc ions. 

Redox reactions occur when electrons are transferred between atoms or molecules. Most first-year chemistry students have performed the redox reaction that occurs spontaneously when metallic zinc is placed in a beaker containing an aqueous solution of copper sulfete. A vigorous exothermic reaction ensues and at its conclusion, the zinc has dissolved, the solution has lost its blue tint, and an orange solid has formed. The reaction that occurs is the following ... 

The chemistry of fluorine is dominated by its electronegativity, which is the highest of all elements. The colorless gas F2 has an estimated standard electrode potential E° (Chapter 15) of +2.85 V for reduction to F (cf. + 1.36 V for Cl2 to Cl-), and thus F2 immediately oxidizes water to oxygen (E° = +1.23 V), and 2% aqueous NaOH to the gas F20. Obviously, F2 cannot be made by electrolysis of aqueous NaF. The usual preparation involves electrolysis of HF-KF melts in a Monel (Cu-Ni alloy) or copper apparatus. 

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