Structure of sulfides

It is likely that the lead and sulfur atoms in most of the lead sulfarsenites and related minerals have the tercovalent argonic structures Pb—- and S y+, as in galena. Nowacki (1969) has published a valuable summary of results of structural studies of the so-called sulfosalt minerals, in relation to a system of classification of the structures that he has developed. Many structures of sulfide minerals have been determined by him and his coworkers. 

Sulfides play an important role in hydrotreating catalysis. Whereas oxides are ionic structures, in which cations and anions preferably surround each other to minimize the repulsion between ions of the same charge, sulfides have largely covalent bonds as a consequence there is no repulsion which prevents sulfur atoms forming mutual bonds and hence the crystal structures of sulfides differ, in general, greatly from those of oxides. 

Many other structures of sulfide minerals have been determined. Most of them conform reasonably well to the structural principles described in this book, but some have surprising features that have not yet been incorporated in the system of structural chemistry,84 and in general the reasons for the choice of one structure rather than another are not yet evident. The general structure theory of the sulfide minerals still awaits formulation. 

Vaughan, D. J. Tossell, J. A. (1983) Electronic structures of sulfide minerals -theory and experiment. Phys. Chem. Minerals, 9, 253-62. 

Figure 15.31 Structure of sulfide products derived from the FLP cleavage of disulfides [164],...

E. Makovich, "Crystal Structures of Sulfides and other Chalcogenides," Sulfide Mineralogy and Geochemistry, Reviews in Mineralogy and Geochemistry, Mineralogical Society of America, Vol. 61, pp.7-125,2006... 

The semiconductive properties and tunnel structure of sulfide and transition-metal oxides led to the use of these materials in lithium power sources (Table 2.5). Several lithium-based chemistries were successfully applied to replace the prior system Zn/AgO and later the lithium-iodine batteries in implantable medical devices [59-61]. For example, Li//CuO, Li//V205, Li//CF and more recently Li// Ag2V40ii couples have been adopted to power cardiac pacemakers requiring less that 200 pW [62,63]. The lithium/carbon monofluoride (Li//CFJ primary cells are very attractive in several applications because of the double energy density with respect to the state-of-the-art LiZ/MnOa primary batteries (theoretically 2203 against 847 Wh kg ). 

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