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34-455: (Redirected from E-2 ) E2 , e2 , E02 , E.II , e or E-2 may refer to: Science and technology [ edit ] E2 reaction, a type of elimination reaction Honda E2 , one of the predecessors of Honda's ASIMO robot E2, a communications channel defined in the E-carrier standard G 2 (mathematics) (old name E2 or E 2 ),

68-803: A class of 4-6-2 steam locomotives built by the American Locomotive Company in 1923 Roads and footpaths [ edit ] E02 expressway (Sri Lanka) , in Sri Lanka E2 European long distance path , a long-distance footpath that runs from Galway in Ireland to France's Mediterranean coast North–South Expressway Southern Route (E2), in Malaysia European route E002 , in Azerbaijan and Armenia E2 expressway (Philippines) , expressway route in

102-434: A collaborative web-based community consisting of a database of interlinked user-submitted written material Arts and entertainment [ edit ] E (album) , a 2007 album by Eros Ramazzotti Television [ edit ] " E² ", an episode of Star Trek: Enterprise MTV e2 , a Canadian entertainment news program that airs on MTV Canada E2 (TV channel) , a Turkish TV channel e2 by SKY PerfecTV! ,

136-487: A group Biology and medicine [ edit ] Ubiquitin-conjugating enzyme , a protein component of proteasome-mediated protein degradation E2 regulatory sequence , for the insulin gene Levuglandin E2 , an aldehyde Prostaglandin E2 , an abortifacient Prostaglandin E2 receptor , a human gene Iodine-deficiency (ICD-10 code: E02) Estradiol , an estrogen steroid hormone Dihydrolipoyl transacetylase ,

170-500: A large stainless steel grille and pilot ornamentation. UP's advertising from that era often had renditions of their locomotives emphasizing their bulbous and shiny noses . All four "B" units (SF-2, SF-3, LA-2, LA-3) went to the Union Pacific; they were used until 1953, when they were "rebuilt" into E8 locomotives. These rebuilds utilised little of the previous locomotives and were effectively trade-ins. The driving "A" unit of

204-455: A metal-carbene complex. In these reactions, it is the carbon adjacent to the metal that undergoes α-elimination.) In certain special cases, γ- and higher eliminations to form three-membered or larger rings is also possible in both organic and organometallic processes. For instance, certain Pt(II) complexes undergo γ- and δ-elimination to give metallocycles. More recently, γ-silyl elimination of

238-674: A postcode district in the E postcode area for east London, England Private E-2 , a pay grade for the rank of Private in the US Army E2 (nightclub) , a nightclub in Chicago, US Eternity II puzzle , a puzzle competition E-II Holdings, Inc., an investment holding company formerly owned by Meshulam Riklis , and later by Carl Icahn E2 grade, an assessment of difficulty in rock climbing See also [ edit ] E2c, earphones by Shure 2E (disambiguation) EII (disambiguation) [REDACTED] Topics referred to by

272-561: A satellite television service in Japan operated by SKY Perfect Transport [ edit ] Air [ edit ] Northrop Grumman E-2 Hawkeye , an American carrier-based AWACS aircraft Fokker E.II , a 1915 German single-seat monoplane fighter aircraft Pfalz E.II , a German aircraft powered by the Oberursel U.I engine Taylor E-2 , a small, light and simple utility aircraft Embraer E-Jet E2 family , an updated version of

306-460: A silylcyclobutyl tosylate has been used to prepare strained bicyclic systems. Many of the concepts and terminology related to elimination reactions were proposed by Christopher Kelk Ingold in the 1920s. EMC E2 The EMC E2 was an American passenger-train diesel locomotive which as a single unit developed 1,800 horsepower (1,300 kW), from two (2) 900 horsepower (670 kW) prime movers. These locomotives were typically operated as

340-690: A unit set ( A - B - B ) or ( A - B - A ); where the three unit lashup developed 5400 horsepower. This was almost the ideal horsepower required (6,000 horsepower or 4,500 kilowatts) for the tonnage of a 15 - 18 car passenger train, operated over the ruling grades of virtually all of the mileage between major American cities. The units were of the A1A-A1A wheel arrangement , and manufactured by Electro-Motive Corporation (EMC), later Electro-Motive Diesel (EMD) of La Grange, Illinois . Two sets (each of three units, A-B-B) (5,400 horsepower or 4,000 kilowatts) were produced in 1937 for named passenger trains ;

374-439: Is different from Wikidata All article disambiguation pages All disambiguation pages Elimination reaction#E2 mechanism The E2 mechanism, where E2 stands for bimolecular elimination , involves a one-step mechanism in which carbon-hydrogen and carbon-halogen bonds break to form a double bond ( C=C Pi bond ). The specifics of the reaction are as follows: An example of this type of reaction in scheme 1

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408-745: Is favored over substitution when For example, when a 3° haloalkane is reacts with an alkoxide, due to strong basic character of the alkoxide and unreactivity of 3° group towards S N 2, only alkene formation by E2 elimination is observed. Thus, elimination by E2 limits the scope of the Williamson ether synthesis (an S N 2 reaction) to essentially only 1° haloalkanes; 2° haloalkanes generally do not give synthetically useful yields, while 3° haloalkanes fail completely. With strong base, 3° haloalkanes give elimination by E2. With weak bases, mixtures of elimination and substitution products form by competing S N 1 and E1 pathways. The case of 2° haloalkanes

442-452: Is relatively complex. For strongly basic nucleophiles (p K aH > 11, e.g., hydroxide, alkoxide, acetylide), the result is generally elimination by E2, while weaker bases that are still good nucleophiles (e.g., acetate, azide, cyanide, iodide) will give primarily S N 2. Finally, weakly nucleophilic species (e.g., water, alcohols, carboxylic acids) will give a mixture of S N 1 and E1. For 1° haloalkanes with β-branching, E2 elimination

476-535: Is still generally preferred over S N 2 for strongly basic nucleophiles. Unhindered 1° haloalkanes favor S N 2 when the nucleophile is also unhindered. However, strongly basic and hindered nucleophiles favor E2. In general, with the exception of reactions in which E2 is impossible because β hydrogens are unavailable (e.g. methyl, allyl, and benzyl halides), clean S N 2 substitution is hard to achieve when strong bases are used, as alkene products arising from elimination are almost always observed to some degree. On

510-534: Is the reaction of isobutylbromide with potassium ethoxide in ethanol . The reaction products are isobutene , ethanol and potassium bromide . E1 is a model to explain a particular type of chemical elimination reaction. E1 stands for unimolecular elimination and has the following specifications 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. If S N 1 and E1 pathways are competing,

544-451: Is α-elimination. For a carbon center, the result of α-elimination is the formation of a carbene, which includes "stable carbenes" such as carbon monoxide or isocyanides . For instance, α-elimination the elements of HCl from chloroform (CHCl 3 ) in the presence of strong base is a classic approach for the generation of dichlorocarbene , :CCl 2 , as a reactive intermediate. On the other hand, formic acid undergoes α-elimination to afford

578-509: The traction motors . In addition the locomotives contained steam generators for passenger car heating. An independent auxiliary diesel powered electric generator was housed in the first car of the train consist. This car was a combination power/baggage/post office, or crew dormitory. This car provided electric power for train-line "hotel" power for their named train set(s), to include the air conditioning, dining, lounge, and entertainment. The power cars were required for these train sets because of

612-627: The E-jet family Eastman E-2 Sea Rover , a 1920s seaplane Eurowings Europe (former IATA code: E2), an Austrian airline subsidiary of Lufthansa Kampuchea Airlines (former IATA code: E2), a Cambodian airline Rail [ edit ] E2 Series Shinkansen , a Japanese high-speed train EMC E2 , an early American passenger-train diesel locomotive LB&SCR E2 class , a class of 0-6-0T steam locomotives designed by Lawson Billington PRR E2 , an American PRR 4-4-2 locomotive CNW Class E-2 ,

646-594: The E1 pathway can be favored by increasing the heat. Specific features : The reaction rate is influenced by the reactivity of halogens , iodide and bromide being favored. Fluoride is not a good leaving group, so eliminations with fluoride as the leaving group have slower rates than other halogens . There is a certain level of competition between the elimination reaction and nucleophilic substitution . More precisely, there are competitions between E2 and S N 2 and also between E1 and S N 1 . Generally, elimination

680-518: The EA, E1 and E2 were each built for a specific railroad and train, they were largely identical mechanically and were a step further away from the concept of custom-built motive power, integrated into a particular streamliner ; and towards mass-produced standardized locomotives. This transition was achieved with the E3 , E4 , E5 , and E6 , EMC (later EMD)'s next models. The E2's profile was more aggressive than

714-678: The Philippines San'yō Expressway , Hiroshiwa-Iwakuni Road, Ogori Road and Yamaguchi-Ube Road, numbered as E2 in Japan Submarines [ edit ] HMS E2 , an E-class submarine of the Royal Navy USS E-2 , an E-class submarine of the US Navy Other transport [ edit ] London Buses route E2 , England Other uses [ edit ] E-2 visa , a type of US visa E2,

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748-569: The SF set, SF-1, (the "Queen Mary") went to the Southern Pacific; it was likewise "rebuilt" into EMD E7 #6017. The "A" unit of the LA set, LA-1, went to the Chicago and North Western (#5003A) and was scrapped in 1953 after it was destroyed in a head-on collision near Rhinelander, Wisconsin . No E2 survives today. However the pair of Winton Model 201A V12 diesel engines from SF-1 (the lead unit of

782-568: The electrical demand of their feature cars. The E2 was the third model in a long line of passenger diesels of similar design known as EMD E-units . The E2, along with the more-or-less simultaneous EA/EB units for the Baltimore and Ohio Railroad and the E1 units for the Atchison, Topeka and Santa Fe Railway , represented an important step in the evolution of the passenger diesel locomotive. While

816-546: The ethyl (0.99) and isopropyl (1.72) analogues suggest competition between the two reaction modes. β-Elimination, with loss of electrofuge and nucleofuge on vicinal carbon atoms, is by far the most common type of elimination. The ability to form a stable product containing a C=C or C=X bond, as well as orbital alignment considerations, strongly favors β-elimination over other elimination processes. However, other types are known, generally for systems where β-elimination cannot occur. The next most common type of elimination reaction

850-721: The first set (SF-1, SF-2, and SF-3) for the City of San Francisco . These motive-power sets were jointly owned and operated by the Union Pacific Railroad , the Chicago and North Western Railway , and the Southern Pacific Railroad . The second A-B-B set (LA-1, LA-2, and LA-3) was used for the City of Los Angeles ; and, was jointly owned and operated by the UP and CNW only. The first locomotive power unit

884-602: The nicknames that these locomotives acquired, because of these portholes and prominent nose, was "Queen Mary," after the British Cunard liner had recently been put in service. The Union Pacific Railroad also referred to the schedule of the "City of San Francisco," a passenger train hauled by these locomotives, as sailings. Later E units for Union Pacific, including E7 locomotives, were ordered modified with extra porthole style windows. The units were painted in Union Pacific's Armour Yellow with Leaf Brown roofs and undersides,

918-400: The other hand, clean E2 can be achieved by simply selecting a sterically hindered base (e.g., potassium tert -butoxide). Similarly, attempts to effect substitution by S N 1 almost always result in a product mixture contaminated by some E1 product (again, with the exception of cases where the lack of β hydrogens makes elimination impossible). In one study the kinetic isotope effect (KIE)

952-516: The same colors as UP's previous streamliners (the M-10000 etc.). Color photographs indicate that UP modified their color scheme with slate gray roofs around mid-1941. There was extensive stainless steel on the noses, upon which were displayed the owning railroads' heralds in color. The bulbous nose and stainless steel ornamentation of the E2 evoked the nose design of the UP's M-10003 to M-10006 streamliner locomotives, which were also bulbous, featuring

986-447: The same term This disambiguation page lists articles associated with the same title formed as a letter–number combination. If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=E2&oldid=1237276694 " Category : Letter–number combination disambiguation pages Hidden categories: Short description

1020-471: The second element of the multienzyme pyruvate dehydrogenase complex Acireductone dioxygenase (iron(II)-requiring) , an enzyme Haplogroup E2 (Y-DNA) , a human Y-chromosome DNA haplogroup Computing [ edit ] E2 (cipher) , a block cipher submitted to the AES competition by NTT Tungsten E2 , a business-class Palm OS-based handheld computer Motorola ROKR E2 , a smartphone Everything2 ,

1054-459: The sloping snouts of previous EMC passenger power, so they gained a " bulldog nose " nickname. Subsequent blunt-snouted passenger units are sometimes also called this, but the E2's nose is by far the most bulbous among the E and F series locomotives. The seven porthole windows on the sides were one less than its predecessors in Union Pacific's diesel streamliner fleet, the M-10003 to M-10006 . One of

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1088-426: The stable products water and carbon monoxide under acidic conditions. α-Elimination may also occur on a metal center, one particularly common result of which is lowering of both the metal oxidation state and coordination number by 2 units in a process known as reductive elimination . (Confusingly, in organometallic terminology, the terms α-elimination and α-abstraction refer to processes that result in formation of

1122-456: Was determined for the gas phase reaction of several alkyl halides with the chlorate ion. In accordance with an E2 elimination the reaction with t-butyl chloride results in a KIE of 2.3. The methyl chloride reaction (only S N 2 possible) on the other hand has a KIE of 0.85 consistent with a S N 2 reaction because in this reaction type the C-H bonds tighten in the transition state. The KIE's for

1156-488: Was the control cab, or "A" unit , while the other two were cabless boosters, or "B" units . The control cab and booster units were designed for multiple unit operation (the first in diesel motive power). A single engine crew in the cab, remotely monitored and controlled all three motive power units from a single control station in the cab. The locomotives were diesel-electrics with two 900 hp Winton 201-A engines each, with each engine driving its own generator to power

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