Cations selenium

N. Burford, j. Passmore and J. C. P. Sanders, Chap. 2, Preparation, Structure and Energetics of the Homopoly-atomic Cations of Groups 16 and 17, in J. F. Liebman and A. Greenburg (eds.). From Atoms to Polymers Isoelec-tronic Analogies, VCH PubL, Honda, 1989, pp. 53-108. J. Passmore, Chap. 19 Homopolyatomic Selenium Cations... 

Cyclic selenium cations are known as monocations Se + observed in selenium vapor by mass spectrometry, and as dications Se 2+ of which... 

Selenium can be oxidized even by 100% H2S04 to a dark green solution and by oleum, to an orange solution which have been shown to contain the Se + and Se + cations respectively. These sulphur and selenium cations can also be prepared in other very weakly basic media. For example, solutions of these cations in fluorosulphuric acid can be conveniently obtained by oxidizing the element with S2OaF2. 

When the polysulfur and selenium cationic clusters S8+ and Se8+ are reacted with Fe(CO)5 or Fe2(CO)9, different iron carbonyl cluster cations are isolated depending on the nature of the counteranion used. With SbF6 as the counteranion, [Fe3(E2)2(CO)10][SbF6]2SO2(E = S (8), Se (9)) is isolated from the reaction of E8+ and iron carbonyl. The structure of 9 (Fig. 5) has been established by X-ray methods. The cluster cation consists... 

Salts of the sulfurnitrogen selenium cation radicals [SnSe3 N2]+ (n = 1,2) have dimeric structures similar to thatof S6N42+ (7).135,136... 

The species, SeJ and TeJ, appear to be square-planar like whose similarity is supported by theoretical calculations that treat all of them as 6-ir electron systems.The yellow selenium cation is obtained by treating elemental selenium with fluorosulfuric acid, fuming sulfuric acid, sulfur trioxide, disulfuric acid, or antimony pentafluoride. The red tellurium cation is obtained simi-larly. = ... 

Passmore, J., "Homopolyatomic Selenium Cations and Related Halopolyselenium Cations," In The Chemistry of Inorganic Ring Systems Steudel, R., Ed. Elsevier New York, 1992 p 373. 

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