AlkeneIn organic chemistry, an alkene is a hydrocarbon containing a carbon–carbon double bond. The double bond may be internal or in the terminal position. Terminal alkenes are also known as α-olefins. The International Union of Pure and Applied Chemistry (IUPAC) recommends using the name "alkene" only for acyclic hydrocarbons with just one double bond; alkadiene, alkatriene, etc., or polyene for acyclic hydrocarbons with two or more double bonds; cycloalkene, cycloalkadiene, etc.
Catalytic converterA catalytic converter is an exhaust emission control device that converts toxic gases and pollutants in exhaust gas from an internal combustion engine into less-toxic pollutants by catalyzing a redox reaction. Catalytic converters are usually used with internal combustion engines fueled by gasoline or diesel, including lean-burn engines, and sometimes on kerosene heaters and stoves. The first widespread introduction of catalytic converters was in the United States automobile market. To comply with the U.S.
DichlorocarbeneDichlorocarbene is the reactive intermediate with chemical formula CCl2. Although this chemical species has not been isolated, it is a common intermediate in organic chemistry, being generated from chloroform. This bent diamagnetic molecule rapidly inserts into other bonds. Dichlorocarbene is most commonly generated by reaction of chloroform and a base such as potassium tert-butoxide or aqueous sodium hydroxide. A phase transfer catalyst, for instance benzyltriethylammonium bromide, facilitates the migration of the hydroxide in the organic phase.
Picric acidPicric acid is an organic compound with the formula (O2N)3C6H2OH. Its IUPAC name is 2,4,6-trinitrophenol (TNP). The name "picric" comes from πικρός (pikros), meaning "bitter", due to its bitter taste. It is one of the most acidic phenols. Like other strongly nitrated organic compounds, picric acid is an explosive, which is its primary use. It has also been used as medicine (antiseptic, burn treatments) and as a dye. Picric acid was probably first mentioned in the alchemical writings of Johann Rudolf Glauber.
Iron–sulfur world hypothesisThe iron–sulfur world hypothesis is a set of proposals for the origin of life and the early evolution of life advanced in a series of articles between 1988 and 1992 by Günter Wächtershäuser, a Munich patent lawyer with a degree in chemistry, who had been encouraged and supported by philosopher Karl R. Popper to publish his ideas. The hypothesis proposes that early life may have formed on the surface of iron sulfide minerals, hence the name.
Fries rearrangementThe Fries rearrangement, named for the German chemist Karl Theophil Fries, is a rearrangement reaction of a phenolic ester to a hydroxy aryl ketone by catalysis of Lewis acids. It involves migration of an acyl group of phenol ester to the aryl ring. The reaction is ortho and para selective and one of the two products can be favoured by changing reaction conditions, such as temperature and solvent. Despite many efforts, a definitive reaction mechanism for the Fries rearrangement has not been determined.
MethanogenesisMethanogenesis or biomethanation is the formation of methane coupled to energy conservation by microbes known as methanogens. Organisms capable of producing methane for energy conservation have been identified only from the domain Archaea, a group phylogenetically distinct from both eukaryotes and bacteria, although many live in close association with anaerobic bacteria. The production of methane is an important and widespread form of microbial metabolism. In anoxic environments, it is the final step in the decomposition of biomass.
