Dioxetane

Dioxetanes are heterocyclic organic chemical compounds, consisting of a four-membered ring having in addition to two carbon and two oxygen atoms. The 1,2-dioxetane is therefore an organic peroxide, whereas the 1,3- dioxetane is a cyclic acetal.

History and biological significance

Some naturally occurring 1,2- dioxetanes and their α - keto derivatives ( dioxetanones, α - peroxylactones ) are the cause of bioluminescence. In the 1960s, biochemists came to the conclusion that these compounds in fireflies (also fireflies Lampyridae, fireflies english ) and other organisms, bioluminescence showed, due to instability possessed a " flowing " occurrence. Then the first example of a stable dioxetane at the University of Alberta in 1968 found in Edmonton. This 3,3,4 -trimethyl-1 ,2-dioxetane dissolves with yellow color in benzene. After heating the solution to 333 Kelvin (60 ° C) the substance decomposed slowly and not - as expected - exploded to acetone and acetaldehyde emission of pale - blue light.

The second example, a dioxetane, the symmetrical 3,3,4,4 -tetramethyl- 1 ,2-dioxetane, was briefly thereon. The yellow crystals of the substance sublimated even when stored in the refrigerator. The solution in benzene also slowly emitted blue light with decomposition. By appropriate substitution with fluorescent under UV light, the compounds of the color of emitted light was changed. Since the 3,3,4,4 - tetramethyl-1 ,2-dioxetane has been an object of study of many scientists to elucidate the mechanisms of bioluminescence, this was soon one of the world's best-studied symmetric connections.

Representation

The biosynthesis of dioxetanes and dioxetanones is from a luciferin, which is usually a derivative of a nitrogen-containing polycyclic compound, which contains imidazole as a structural element. The organisms convert this luciferin with molecular oxygen in the presence of Ca2 ions to special species-specific luciferases to the light emitting end product. In the laboratory scale, dioxetanes of cis -2- butene derivatives such as 2,3 -dimethyl -2-butene may be prepared by reaction with oxygen or hydrogen peroxide and bromine, and subsequent cyclization of the resulting hydroperoxide with a base.

Use

Luminescent jewelry items such as bracelets, necklaces and rings contain artificial derivatives of dioxetanes which additionally contain a carbonyl group; this dioxetanones - such as 1,2- Dioxetandion - decompose with elimination of carbon dioxide and light emission. Other dioxetanes are used in clinical analysis for the detection of low concentrations of bodily fluids (such as blood ). Dioxetanes can be used in detection systems constructed in accordance with the luciferases and highly specific and suitable for minimal amounts of qualitative and quantitative detection of ATP ( detection limit of 10 to 11 moles), NADH and oxygen.