Sulfur hydrides sulfanes

Higher oxidation numbers are stabilized, in general, by oxygen and fluorine however, compounds of hydrogen with sulfur are limited to those in which sulfur is bivalent. 

The most important hydride, H2S, is an important constituent of many types of natural gas. H2S, with its characteristic rotten egg smell, is as poisonous as hydrogen cyanide (fatal at 100ppm ), and because it is much more common, presents a greater menace. 

An alternative host for these bacteria are shrimps which tend to dominate around vents in the Atlantic Ocean. 

On the sea bed, at a depth of several thousand metres, signs of life are usually sparse. However, around hydrothermal vents, complex ecosystems have developed, and around 500 new species have been discovered, with hydrogen-sulfide-consuming bacteria forming the first link in the food chain. 

A black smoker hydrogen sulfides and heavy-metal sulfides being spewed from a vent in the sea floor. These can rise to heights of 15 metres. 

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Sulfur forms hydrides (sulfanes) only in oxidation number +2 (or lower). These have the general formula H2S (where n represents the number of sulfur atoms in the chain). 

Gmelin Handbook of Inorganic Chemistry , Springer, Berlin, includes the following Sulfur A1 (History, 1942) A2 (Occurrence, Technology, 1953) A3 (The Element, 1953) B1 (Hydrides and Oxides, 1953) B2 (Sulfur-Oxygen Acids, 1960) B3 (Compounds, 1963) Sulfur Suppl. Vol. 1 (Thionyl Halides, 1978) Sulfur Suppl. Vol. 2 (Sulfur Halides, 1978) Sulfur Suppl. Vol. 3 (Sulfur Oxides, 1980) Sulfur Suppl. Vol. 4a/b (Sulfanes, 1983) as well as several volmnes on S-N chemistry. 

The hydrides of sulfur are called sulfanes. Hydrogen sulfide, H2S, is the most important and most stable. It is a... 

If acid is added to polysulfides (see Section 12.3.2), a mixture of acids containing S—S bonds results H2S2, H2S3, H2S4, etc. As these are analogues of carbon and silicon hydrides, they are called sulfanes. Sulfur has the highest tendency after carbon to form bonds to itself, that is, to catenate. 

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