Copper telluride

Fig. 3. Tellurium helices in copper telluride halides. (Redrawn from J. Fenner and H. Schulz, Acta Cryst. B35, 307 (1979), Fig. 2, p. 311.)...

Fig. 4. Spectral reflectance measurements in copper telluride halides. (Redrawn from A. Rabenau, H. Rau, and G. Rosenstein, Solid State Commun. 7, 1281 (1969), Fig. 1,...

Copper table, in silicon casting, 22 507 Copper telluride, 24 409 Copper thiocyanate, molecular formula and uses, 7 778t Copper-tin alloys, 24 796... 

Although this procedure yields tellurium as the same compound found in the original feedstock, the copper telluride is recovered in a comparatively pure state which is readily amenable to processing to commercial elemental tellurium or tellurium dioxide. The upgraded copper telluride is leached with caustic soda and air to produce a sodium tellurite solution. The sodium tellurite solution can be used as the feed for the production of commercial grade tellurium metal or tellurium dioxide. 

Copper Alloys. Tellurium is alloyed with copper for various purposes. Frequendy the tellurium is added to molten copper as a copper telluride (46.3 % Te) master alloy, taking advantage of the peritectic melting point of 1051°C. 

PXRD data were obtained at high angle to monitor the formation of copper telluride. 

The formation of semiconducting copper telluride inside the spatially confined pores of MCM-41 may be a step towards the formation of semiconducting nanowires. 

Unlike the copper telluride clusters, it has not yet proven possible to generate large silver telluride cluster complexes using a combination of R3P, Ag-X and Te(SiMe3)2. This suggests that the phosphine ligands are unable to kinetically... 

CuTe COPPER TELLURIDE 633 Fe2Br4[g] DIIRON TETRABROMIDE (GAS) 682... 

Although this strategy works well for copper-sulfide, copper-selenide, and copper telluride particles, it has not been shown that related silver- and gold-chalco-... 

The copper atoms in the vast majority of the clusters can be assigned a formal charge of +1, while the chalcogen ligands are formally viewed as E or RE groups. Some of the selenium-bridged species, however - and nearly all copper telluride clusters - form nonstoichiometric compounds that display mixed valence metal centers in the formal oxidation states 0 and +I or +I and +11. These observations correlate with those made for the binary phases CU2S, Cu2 xSe, and Cu2- Te [38-40]. 

According to the general reaction pathway shown in Schemes 3.8 and 3.9, the syntheses of ligand-stabilized copper telluride clusters have mainly been achieved in one of three different ways [11, 16, 19, 20, 24, 25, 31, 61]. 

In the case of copper telluride clusters, the turning point in size has not yet been reached where the whole core structures display bulk structure characteristics, as seen for the copper selenide species. Nevertheless, the tellurium frameworks in the largest cluster compounds, 85-87 display hexagonal structure properties. Powder... 

Table 3.1 Classification of copper telluride clusters into stoichiometric or mixed valence, according to the types of tellurium ligand. 

Figure 3.66 Molecular structures of stoichiometric copper telluride clusters [CufiTejlPCyPhzls] (54), [CugTe4(PPh3)7] (55), [Cun2Te6(PPh3)s] (56). [Cui6Teg(PPhnPr2)io]...

In the following section, all cluster structures will be briefly described and discussed according to the division into four groups indicated in Table 3.1. The molecular structures of the stoichiometric copper telluride clusters 54-58 are shown in Figure 3.66. 

Some reactions of copper(I) chloride or copper(I) acetate lead to the formation of copper telluride clusters that contain Te-Te bridges (59-62 see Figure 3.67). 

This cluster represents the only example of a copper-telluride-tellurolate cluster yet isolated with a distinct structural relationship with its silver analog. 

Figure 5.15 The UV-visible solid-state absorption spectra (mull in nujol) of the mixed-valence copper telluride clusters [Cui6Te9(PPh3)g] (7), [Cu23Tei3(PPh3)io] (8), and [Cu44Te23(PPhnPr2)i5] (9).

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