Search results
Results from the WOW.Com Content Network
A series of processes that involve carbonization. [2]Carbonization is a pyrolytic reaction, therefore, is considered a complex process in which many reactions take place concurrently such as dehydrogenation, condensation, hydrogen transfer and isomerization.
The conversion of ethanol to ethylene is a fundamental example: [3] [4] CH 3 CH 2 OH → H 2 C=CH 2 + H 2 O. The reaction is accelerated by acid catalysts such as sulfuric acid and certain zeolites. These reactions often proceed via carbocation intermediates as shown for the dehydration of cyclohexanol. [5] Some alcohols are prone to dehydration.
Among the simplest examples are the methenium CH + 3, methanium CH + 5, acylium ions RCO +, and vinyl C 2 H + 3 cations. [2] Until the early 1970s, carbocations were called carbonium ions. [3] In the present-day definition given by the IUPAC, a carbocation is any even-electron cation with significant partial positive charge on a carbon atom.
An example in scheme 2 is the reaction of tert-butylbromide with potassium ethoxide in ethanol. E1 eliminations happen with highly substituted alkyl halides for two main reasons. Highly substituted alkyl halides are bulky, limiting the room for the E2 one-step mechanism; therefore, the two-step E1 mechanism is favored.
MICROORGANISM TYPE ( Bacterium / Fungus ) FOOD / BEVERAGE Acetobacter aceti: bacterium: chocolate [1]Acetobacter aceti: bacterium: vinegar [2]Acetobacter cerevisiae
Download as PDF; Printable version; In other projects Wikimedia Commons; Wikidata item; ... A carbocation is a compound containing a positively charged carbon atom.
The unimolecular S N 1 mechanism proceeds via a carbocation (provided that the carbocation can be adequately stabilized). In the example, the oxygen atom in methyl tert-butyl ether is reversibly protonated. The resulting oxonium ion then decomposes into methanol and a relatively stable tert-butyl cation.
Typically, generating a stable carbocation for a prolonged period of time is difficult, due to the possibility for the cation to be quenched by a β-protons attached to another monomer in the backbone, or in a free monomer. Therefore, a different approach is taken [4] [5] [17] This is an example of a controlled/living cationic polymerization.