Chalcogen chemistry

Sheldrick WS (2007) Polychalcogenides. In DevrUanova FA (ed.), Handbook of chalcogen chemistry New perspectives in sulfur, selenium and tellurium, Royal society of Chemistry Cambridge, UK... 

This important area of boron-chalcogen chemistry has made some tremendous advances, particulary in macropolyhedral systems, in recent years. The topic was recently reviewed7,8 in 1997 and 2002. This section is again ordered in increasing numbers of boron atoms within the cage. 

Polymer formation Scheme 1 Trends in neutral and cationic chalcogen chemistry. 

The hypervalent chalcogen chemistry has been developed to higher coordinated species with various ligands,7 10 where TBP changes to square pyramidal (SP) or octahedral (Oh), etc. Additional atomic orbitals of E, such as an 5-orbital, may operate to stabilize the structures.10b The concept is also extended over linear a-bonds constructed by m ( > 4) atoms with n electrons (extended hypervalent bonds mc-ne (in > 4)).11 14 The approximate molecular orbital model for mc-ne (m > 4) is also exhibited in Scheme la, exemplified by 4c-6e. 

The main purpose of this chapter is to review the development of hypervalent chalcogen chemistry after the book of "Chemistry of Hypervalent Compounds edited by Akiba (1999).5 Although several types of compounds may belong to hypervalent ions or molecules by the definition,3a such hypervalent chalcogen compounds (E = S, Se, and Te) will be mainly discussed here that contain CT-type linear bonds.15... 

In this section, we look more closely at what effect the chalcogen atom has on the properties of the molecular conductors we describe. We do not attempt to review exhaustively all the chalcogen-containing components in electroactive systems, to do so would be a colossal task. Instead, carefully chosen examples and studies illustrate how chalcogen chemistry is used in the design and manipulation of electroactive materials, and ultimately how it effects suitability for molecular device applications. 

Since 1990, several reviews have appeared covering silicon-chalcogen chemistry. These include the spectroscopic properties of silicon-sulphur compounds along with structural data1. The synthesis of metal-chalcogen clusters using (Me3Si)2X (X = S, Se,... 

Devillanova, F. (Ed.). (2006). Handbook of Chalcogen Chemistry New Perspectives in Sulfur, Selenium and Tellurium. Cambridge RSC Publishing. A book devoted solely to the chemistry of the chalcogens. Greenwood, N. N., Eamshaw, A. (1997). Chemistry of the Elements (2nd ed.). Oxford Butterworth-Heinemann. The monumental reference book in inorganic chemistry. Extensive coverage of sulfur, selenium, and tellurium chemistry in Chapters 15 and 16. 

WeTl now consider the reverse of what we discussed above, that is, how a cyclooctachalco-gen ring is assembled, a very common process in chalcogen chemistry. Consider, as an example, the following reaction ... 

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