Epoxy compounds
Epoxy compounds are a group of organic cyclic compounds that contain an epoxy bridge ; H. an oxygen bridge between two carbon atoms, and thus belong to the heterocycles . If the two carbon atoms and the epoxy bridge form a three-membered ring, then we are dealing with epoxides ( oxiranes ). Another special case of the epoxy bridge is a chemical group that forms on the graphite surface when exposed to oxygen .
The name is borrowed from the prefix 'epoxy', which stands for ring-shaped oxygen. In this bridge, a single oxygen atom connects with two directly or not directly connected carbon atoms to form a grouping that occurs either as a three-membered ring (epoxide) or a bridge via a cyclic compound (cyclic ether ).
Epoxy bridges over directly adjacent carbon atoms put a lot of stress on the surrounding bonds and can lead to local rupture of the graphite lattice in the case of graphite. During this process, the individual oxygen atom acts like a mini-wedge that pushes the two carbon atoms aside, thus stretching the connections extremely. This changes the geometry of the atoms involved: the previously firmly bound carbon atoms are now bound to the oxygen atom that sits above the surface of the lattice. The result is a three-dimensional, distorted group that does not fit into the remaining grid.
Epoxy bridges via ring-shaped organic compounds are a frequently occurring structural element, for example with many carbohydrates , lactones , terpenoids ( 1,4-cineole , 1,8-cineole ) etc.
Individual evidence
- ↑ a b Entry on Epoxy Compunds . In: IUPAC Compendium of Chemical Terminology (the “Gold Book”) . doi : 10.1351 / goldbook.E02173 Version: 2.3.3.