Video: Vim li cas Arenes tau txais kev hloov pauv hloov?
2024 Tus sau: Miles Stephen | [email protected]. Kawg hloov kho: 2023-12-15 23:36
Aromatic compounds los yog arenes tau txais kev hloov pauv , nyob rau hauv uas cov aromatic hydrogen hloov nrog ib tug electrophile, li no lawv cov tshuaj tiv thaiv mus los ntawm electrophilic hloov . Hlau cross-coupling xws li Suzuki tshuaj tiv thaiv tso cai tsim cov pa roj carbon-carbon bonds ntawm ob los yog ntau tshaj cov tshuaj tsw qab.
Yog li, vim li cas benzene tsuas yog hloov pauv cov tshuaj tiv thaiv?
Koj kawm hauv tsev kawm ntawv ntawd tshuaj benzene ua tau raug hloov cov tshuaj tiv thaiv vim hais tias cov delocalised electrons nyob rau hauv nws cov qauv yog ib cheeb tsam ntawm high electron ceev. Yog li ntawd tshuaj benzene ua tau teb nrog ib tug electrophile.
Tsis tas li ntawd, Arene txhais li cas? Ib arene los yog aromatic hydrocarbon yog hydrocarbon nrog alternating ob thiab ib daim ntawv cog lus ntawm carbon atoms ua rings. Arene kuj tuaj yeem xa mus rau: Arene (gastropod), ib tug genus ntawm marine snails nyob rau hauv tsev neeg Areneidae.
Tom qab ntawd, ib tus tuaj yeem nug, vim li cas benzene tau hloov pauv electrophilic ntau dua li cov tshuaj tiv thaiv ntxiv?
Benzene yog ib Planar molecule muaj delocalized electrons saum toj thiab hauv qab lub dav hlau ntawm lub nplhaib. Yog li ntawd, nws yog electron nplua nuj. Yog li ntawd, nws yog qhov txaus nyiam heev rau cov tsiaj tsis muaj hluav taws xob xws li, electrophiles . Yog li ntawd, nws tau txais cov tshuaj electrophilic hloov pauv yooj yim heev.
Vim li cas cov tshuaj tsw qab hydrocarbons tau txais kev hloov pauv ntau dua li cov tshuaj tiv thaiv ntxiv siv cov qauv tshuaj los qhia koj cov lus teb?
Lawv tsis muaj reactivity rau ntxiv cov tshuaj tiv thaiv yog vim tus zoo stability ntawm tus nplhaib tshuab uas tshwm sim los ntawm ua tiav π electron delocalization (resonance). Aromatic compounds teb los ntawm electrophilic aromatic hloov cov tshuaj tiv thaiv , hauv tus aromaticity ntawm tus nplhaib system yog khaws cia.
Pom zoo:
Vim li cas cov hnub qub dhau los ntawm kev hloov pauv hloov pauv?
Stellar evolution yog tus txheej txheem uas lub hnub qub hloov pauv nyob rau lub sijhawm. Cov hnub qub uas muaj tsawg kawg yog ib nrab ntawm lub hnub tuaj yeem pib tsim lub zog los ntawm kev sib xyaw ntawm helium ntawm lawv cov tub ntxhais, thaum lub hnub qub ntau dua tuaj yeem sib xyaw cov ntsiab lus hnyav dua raws li cov khoom sib xyaw ua ke
Vim li cas tom qab kev hloov pauv kev hloov pauv tseem ceeb?
Kev hloov pauv tom qab kev txhais lus (PTMs) xws li glycosylation thiab phosphorylation ua lub luag haujlwm tseem ceeb ntawm kev ua haujlwm ntawm hemostatic proteins thiab tseem ceeb heev hauv kev teeb tsa kab mob. Xws li theem nrab hloov pauv rau cov proteins hemostatic muaj ntau yam cuam tshuam rau lawv lub peev xwm los cuam tshuam nrog lwm cov proteins
Dab tsi yog qhov txawv ntawm ib puag ncig kev hloov pauv thiab kev hloov pauv qub txeeg qub teg?
Qhov sib txawv ntawm cov yam ntxwv ntawm cov tib neeg ntawm tib hom yog hu ua variation. Qhov no yog inherited variation. Qee qhov kev hloov pauv yog qhov tshwm sim ntawm qhov sib txawv ntawm ib puag ncig, lossis ib tus neeg ua dab tsi. Qhov no yog hu ua environmental variation
Thaum ib qho kev sib cais ua rau muaj kev hloov pauv hloov pauv ntawm lub ntiaj teb nce ntxiv?
Txij li thaum lub kaw lus raug cais tawm, tsis muaj cua sov tuaj yeem khiav tawm (tus txheej txheem yog li adiabatic), yog li thaum lub zog ntws tawm hauv lub cev, qhov entropy ntawm qhov system nce, piv txwv li Δ Ssys> 0. Yog li ntawd, lub entropy ntawm lub system yuav tsum tau nce rau ib tug spontaneous txheej txheem nyob rau hauv no cais system
Lub zog siv hluav taws xob txuag tau li cas thaum hloov pauv lossis hloov pauv?
Txoj cai lij choj ntawm kev txuag hluav taws xob hais tias rau txhua qhov system, lub zog tsis tuaj yeem tsim lossis rhuav tshem; nws tsuas tuaj yeem hloov ntawm ib daim ntawv mus rau lwm qhov lossis hloov ntawm ib yam khoom mus rau lwm qhov. Mechanical zog los ntawm ob hom: lub zog muaj peev xwm, uas yog khaws cia lub zog, thiab lub zog kinetic, uas yog lub zog ntawm kev txav