Synonyms for benzvalene or Related words with benzvalene
Examples of "benzvalene"
Other classic structures that have been considered as possible benzene isomers are prismane,
and Claus' benzene. Prismane and
were synthesized in the 1970s; Claus' benzene is impossible to synthesize.
is an organic compound and one of several isomers of benzene. It was first synthesized in 1971 by Thomas J. Katz et al.
The 1971 synthesis consisted of treating cyclopentadiene with methyllithium in dimethyl ether and then with dichloromethane and methyllithium in diethyl ether at −45 °C. The hydrocarbon in solution was described as having an extraordinary mephitic odor. Due to the high steric strain present in
, the pure compound easily detonates, for example by scratching.
can be polymerized in a ROMP process to polybenzvalene. This polymer contains highly strained bicyclobutane rings which again makes it a sensitive material. The rings can be isomerized to 1,3-dienes and for this reason polybenzvalene has been investigated as a precursor to polyacetylene.
Having synthesized and studied hexamethylprismane in 1966, Lemal’s group was interested in how a prismane substituted with electron-acceptor instead of donor groups would differ in nature and reactivity. This led to vapor phase photolysis of perfluorohexamethylbenzene (1), which yielded not only the prismane (2), but the dewar benzene (3) and
(4) as well. An English group made the same discovery independently. These strained molecules were remarkably robust and thermally stable as compared with their rather fragile hydrocarbon counterparts, and that intriguing contrast led to further exploration of fluorocarbon chemistry.
The synthesis starts from
(1) and 4-phenyltriazolidone (2), which is a strong dienophile. The reaction is a stepwise Diels-Alder like reaction, forming a carbocation as intermediate. The adduct (3) is then hydrolyzed under basic conditions and afterwards transformed into a copper(II) chloride derivative with acidic copper(II) chloride. Neutralized with a strong base, the azo compound (5) could be crystallized with 65% yield. The last step is a photolysis of the azo compound. This photolysis leads to a biradical which forms prismane (6) and nitrogen with a yield of less than 10%. The compound was isolated by preparative gas chromatography.
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