Chlorine clathrate hydrate

Clathrates are the original host-guest compounds with chlorine clathrate hydrate - a compounds in which a water hydrogen bonded network hosts a molecule of Cl2 - being known since 1810. 

The chemistry of inclusion compounds has a long history Confirmed accounts on the preparation of such chemical species date back to the beginning of the nineteenth century. At that early time Davy, and shortly afterwards Faraday, reported of a chlorine clathrate hydrate... 

Solid-state host-guest chemistry dates to the discovery of chlorine clathrate hydrate by Davey in 1810 and represents cocrystallization of two or more chemically... 

The concept of inclusion is as old as humankind. The hand is capable of a variable assortment of inclusions, and many analogies are appropriate. The first verified examples of inclusion compounds date from the early 1800s. It is instructive to list the dates of record for the preparation of inclusion compounds of various types the chlorine clathrate hydrate by Faraday in 1823, graphite intercalates in 1841, the /3-quinol H2S clathrate in 1849,... 

The history of iaclusion compounds (1,2) dates back to 1823 when Michael Faraday reported the preparation of the clathrate hydrate of chlorine. Other early observations iaclude the preparation of graphite iatercalates ia 1841, the P-hydroquiaone H2S clathrate ia 1849, the choleic acids ia 1885, the cyclodexthn iaclusion compounds ia 1891, and the Hofmann s clathrate ia 1897. Later milestones of the development of iaclusion compounds refer to the tri-(9-thymotide benzene iaclusion compound ia 1914, pheaol clathrates ia 1935, and urea adducts ia 1940. 

As follows from his laboratory notes, the first discovered clathrate hydrate (of chlorine) was observed, but not recognized, by Davy in 1810. Then Cl2, Br2, so2) co2, ch3ci, ch4, c2h, and numerous other gases were shown to form clathrate hydrates [22, 23]. Contrary to inorganic stoichiometric hydrates, those involving hydrocarbons are both non-stoichiometric and crystalline. In addition, gas hydrate composition was found to depend on temperature, pressure, and some... 

Clathrate-Cage Model. The final water model which is of major interest is based on clathrate hydrate cage structures. It was originally proposed by Pauling (116), who noted the existence of clathrate hydrates of many inert gases and suggested, by analogy to the chlorine hydrate,... 

Solid clathrate hydrates are formed under very specific conditions of temperature and pressure. It is one of their most important and remarkable properties that they are often stable solids well above the 0 °C melting point of the most common form of pure ice (symbol Ih, meaning ice-hexagonal). Indeed, some gas hydrates are stable up to 31.5 °C. This property was noted by Davy, who commented on his chlorine (then called oxymuriatic gas) hydrate ... 

Quinol (hydroquinone) crystal was the first composite to be called a clathrate. Nowadays, this term has been adopted for many complexes which consist of a host molecule (forming the basic frame) and a guest molecule (set in the host molecule by interaction). The clathrate that is of interest to this study is the clathrate hydrate, also referred to as gas hydrate. Clathrate hydrates were discovered in 1810 by Sir Humphrey Davy. In his lecture to the Royal Society in 1810, he said that he had found, by several experiments, that the solution of chlorine gas in water freezes more readily than pure water [9]. 

The publication of this series, interestingly enough, coincides with the 200th anniversary of the first report of the synthesis of a clathrate hydrate, that of chlorine, by Humphrey Davy. He reported that a solution of chlorine in water froze at a temperature higher than the ice melting point. Upon decomposition, this unique new material returned unchanged to the starting materials. Clathrate hydrates were likely the first synthetic materials that could be classified as supramolecular. 

Molecular as well as ionic substances can form hydrates, but of an entirely different nature. In these crystals, sometimes referred to as clathrates, a molecule (such as CFI4, CHCI3) is quite literally trapped in an ice-like cage of water molecules. Perhaps the best-known molecular hydrate is that of chlorine, which has the approximate composition Cl2- 7.3H20. This compound was discovered by the great... 

Gas hydrates are a special form of clathrates. Here water is the host molecule. The first gas hydrate (with chlorine) was described in 1818 by Sir Humphrey Davy. Naturally-occurring gas hydrates in Siberia are methane hydrates. 

Sir Humphry Davy discovery of chlorine hydrate 1823 - Michael Faraday formula of chlorine hydrate 1841 - C. Schafhautl study of graphite intercalates 1849 - F. Wohler /Lquinol H2S clathrate 1891 - Villiers and Hebd cyclodextrin inclusion compounds... 

Nevertheless the analogy with clathrate compounds (p. 179) does not go further since it is just the xenon hydrate (1 at. press, at — 3.40 G) which is very much more stable than the argon hydrate (1 at. at —42.8°) likewise the bromine hydrate is more stable than the chlorine hydrate. 

The name clathrate, from the Greek klathron KXaOpov, bolt or lock, since the volatile guest compound is locked into the crystal), was coined by Herbert M. Powell, who studied many of them. Examples of clathrates are provided by the gas hydrates, first identified by Sir Humphrey Davy, who prepared chlorine hydrate by bubbling chlorine into cool water. This hydrate was shown to have the chemical formula 8CI2 46H2O. The anesthetic properties of chloroform have been attributed to the formation of such gas hydrates in brain tissue. ... 

The first known clathrate was a gas hydrate of chlorine, discovered by Davy in 1811 [127]. By 1900, many clathrate compounds had been prepared [128],... 

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