Clathrates

A clathrate is a chemical compound that is made up of a lattice that traps or contains molecules. Clathrate is derived from the Latin clathratus (clatratus), which means "with bars, latticed." The majority of clathrate compounds are polymeric and fully encircle the guest molecule, although clathrates also comprise host-guest complexes and inclusion compounds in current usage. Clathrates are inclusion compounds "in which the guest molecule is in a cage formed by the host molecule or by a lattice of host molecules," according to IUPAC. The term refers to a wide range of molecular hosts, including calixarenes and cyclodextrins, as well as some inorganic polymers such as zeolites. Organic hydrogen-bonded frameworks are used to create clathrate hydrates. These frameworks are made up of molecules that "self-associate" through a series of hydrogen-bonding interactions. Cavities such as dodecahedral, tetrahedral, and hexakaidecahedral cavities may be found in most clathrate crystal formations. Humphry Davy identified clathrate hydrates in 1810. P. Pfeiffer researched clathrates in 1927, and E. Hertel described "molecular compounds" as substances degraded into individual components in solution or gas state according to the mass action law in 1930. H. M. Powell called these chemicals clathrates after analysing their crystal structure in 1945.