Cuprous sulfide

The copper(I) ion, electronic stmcture [Ar]3t/ , is diamagnetic and colorless. Certain compounds such as cuprous oxide [1317-39-1] or cuprous sulfide [22205-45 ] are iatensely colored, however, because of metal-to-ligand charge-transfer bands. Copper(I) is isoelectronic with ziac(II) and has similar stereochemistry. The preferred configuration is tetrahedral. Liaear and trigonal planar stmctures are not uncommon, ia part because the stereochemistry about the metal is determined by steric as well as electronic requirements of the ligands (see Coordination compounds). 

Halb-schatten, m. half-shade, half-shadow Astron.) penumbra. -schwefeleisen, n. iron hemisulfide (supposedly Fe2S). -schwe-felkupfer, n. cuprous sulfide, copper (I) sulfide. -seide, /. half-silk, -seite, f. half-page, halb-seitig, a. relating to one side or half, unilateral half-page, -selbsttatig, a. semiautomatic. -sicher, a. metastable, -spezi-fisch, a. semispecific. 

Based on these considerations, Croft prepared six formulations containing various combinations of NBR and NBR/PVC with CR and SBR and measured their oil, heat and ozone resistance, physical properties, and adhesion characteristics. Whereas the physicals are satisfactory for aU compounds, formulations based on NBR, NBR/PVC with CR performed better on heat and oil aging than the compounds containing SBR as shown in Tables 11.6 and 11.7. However, the adhesion is better with the latter compounds. It has been suggested that cuprous sulfide formed on the wire surface interacts with the double bond in SBR to provide the improvement in adhesion. 

The copper remaining in lead after the above operation is removed by matte formation. Finely divided sulfur is added to molten lead at temperatures slightly above its melting point, and the melt is stirred continuously. Copper sulfide forms and floats on the surface, leaving the bullion substantially free of copper (less than 0.005%). The standard free energies of formation of cuprous sulfide and lead sulfide are about the same the observed separation must, therefore, be due to kinetic factors or to the influence of certain minor impurities that are present in the lead. 

Cuprous sulfide, 7 767 Curative levels, optimizing, 21 803—804 Curatives, in polychloroprene latex compounding, 19 858 Curculin, 24 246 Curdlan, 4 724t 20 577-578... 

Lamache M, Bauer D (1979) Anodic oxidation of cuprous sulfide and the preparation of nonstoichiometric copper sulfide. Anal Chem 51 1320-1322. 

Native copper ore is crushed, concentrated by washing with water, smelted, and cast into bars. Oxide and carbonate ores are treated with carhon in a smeller. Sulfide ore treatment is complex, hut. in brief, consists of smelling to a matte of cuprous sulfide, ferrous sulfide, and silica, which molten matte is treated in a converter by the addition of lime and air is forced under pressure through the mass. The products are blister copper, ferrous calcium silicate slag, and SO . Refining is conducted by electrolysis, and the anode mud is treated to obtain the gold and silver. See Fig. I. 

Cuprous Sulfide, CUjS,mw 159 20, blk solid, mp ca 1100° occurs as the mineral chalcocite (copper glance). Can be prepd by heating CuS in a stream of hydrogen or by other methods (Refs 1, 2, 4 7). Used in protective paint for vessels (Ref 9, P 321... 

The distinction between electronic and electrolytic conductors is not sharp, for many substances behave as mixed conductors that is, they conduct partly electronically and partly electrolytically. Solutions of the alkali and alkaline earth metals in liquid ammonia are apparently mixed conductors, and so also is the jS-form of silver sulfide. Fused cuprous sulfide conducts electronically, but a mixture with sodium or ferrous sulfide also exhibits electrolytic conduction a mixture with nickel... 

The cuprous sulfide, CU2S, is oxidized with oxygen which has been transported through the oxide-sulfate layer by either gaseous or solid-state diffusion. The reaction products at the CU2S surface are CU2O and SO2. 

The concentrate or the rich sulfide ore is then roasted in a furnace through wiiich air is passing. This removes some of the sulfur as sulfur dioxide, and leaves a mixture of Cir.S, FeO, SiO, and other substances. This roasted ore is then mixed with limestone to serve as a flux, and is heated in a furnace. The iron oxide and silica combine with the limestone to form a slag, and the cuprous sulfide melts and can be drawn off. This impure cuprous sulfide is called matte. It is then reduced by blearing air tlirough the molten material ... 

Other stable cuprous compounds are the insoluble substances cuprous oxide, Cu.,0 (red), cuprous sulfide, Cu. S (black), cuprous cyanide, CuCN (white), and cuprous thiocyanate, CuSCN (white). 

Interesting cases of deposition concern compounds where the oxidation state of the metal can take different values, such as copper or tin. Several reports concern the formation of CuxS with x between 1 and 2 [18, 47-50]. Varkey et al. [48] show that cuprous sulfide (CU2S) is formed in TU solutions, using a Cu(I) precursor (CuCl). However it can be obtained also when starting from a cupric salt (Cu(II)) due to the reducing properties of thiourea (and other sulfur precursors) as shown by Nair et al. 

Grozdanov et al. [18, 49, 50] report a direct relation between the TS concentration and the final compound composition. Low concentrations tend to form cuprous sulfide and high ones tend to form cupric sulfide (CuS). It is possible that in the first case the reduction of cupric ions preceeds the deposition step. Similar effects may occur in the tin sulfide system. Engelken et al. [64] report the formation of SnxS with some variations in x using S dissolved in propionic acid as the sulfur precusor in this study the solution was non-aqueous which is rather rare in CBD studies. 

Chemical deposition can be anticipated for photothermal conversion applications in architecture. Nair et al. have also proposed the use of cuprous sulfide for this objective [47]. 

Chemically deposited non stoichiometric cuprous sulfide films (Cui.gS) have been used as conducting layers as reported by Grozdanov et al. [50]. The films, deposited at 40 °C, present a resistivity of 2.10 Q.cm. In addition they present optical transmission values between 50 and 70% in the visible range for a 0.12 pm thick film. These properties have been used for ohmic contacts to ferroelectric films and transparent conducting coatings on polymers. These films can also be used as chemical sensors for Cu + ions. Note that due to the low deposition temperature polymer substrates can be used [61]. 

Cuprous Sulfide. CujS, mol wt 159.15. Cu 79.85%, S 20.15%. Occurs in nature as the mineral chatco-citr also called copper glance (grey, black, green, blue, or violet rhombic crystals). Prepn Glemser, Sauer in Handbook of Preparative Inorganic Chemistry, vol. 2, G. Brauer, Ed. (Academic Press, New York, 2nd ed., 1965) p 1016. 

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