Qhov sib txawv tseem ceeb ntawm nucleophile thiab electrophile yog qhov nucleophile yog ib yam khoom uas nrhiav qhov chaw zoo thaum lub electrophiles nrhiav qhov chaw tsis zoo uas muaj cov hluav taws xob ntxiv.
Peb tuaj yeem hu cov tsiaj uas tshwm sim vim kev sib cais raws li "electrophiles" thiab "nucleophiles". Peb yuav tham txog dab tsi yog ib qho nucleophile lossis electrophile hauv kab lus no. Electrophiles thiab nucleophiles yog qhov tseem ceeb rau kev pib tshuaj lom neeg. Tsis tas li ntawd, lawv tseem ceeb heev los piav qhia txog qhov kev tshwm sim tshwm sim li cas. Nyob rau hauv cov organic chemistry, peb muaj peev xwm categorize cov tshuaj tiv thaiv mechanisms nyob ntawm seb thawj hom (xws li ib tug electrophile los yog nucleophile) uas pib mus tua lwm hom. Nucleophilic hloov pauv, nucleophilic ntxiv, electrophilic hloov, thiab electrophilic ntxiv yog plaub yam loj ntawm cov txheej txheem piav qhia txog cov tshuaj tiv thaiv organic.
Nucleophile yog dab tsi?
A nucleophile yog ib qho tsis zoo ion lossis ib qho nruab nrab molecule uas muaj tsawg kawg yog ib qho tsis sib koom ua ke. Nucleophile yog ib yam khoom uas muaj electropositive heev, yog li ntawd, nyiam cuam tshuam nrog cov chaw zoo. Nws tuaj yeem pib cov tshuaj tiv thaiv siv ib leeg electron khub. Piv txwv li, thaum ib tug nucleophile reacts nrog ib tug alkyl halide, ib leeg khub ntawm nucleophile tawm tsam cov pa roj carbon atom uas bears lub halogen. Cov pa roj carbon atom no muaj ib feem zoo nqi vim qhov sib txawv ntawm cov electronegativity qhov tseem ceeb ntawm cov pa roj carbon no thiab cov halogen atom. Tom qab cov nucleophile txuas rau cov pa roj carbon, cov halogen tawm. Peb hu cov tshuaj tiv thaiv no ua cov tshuaj tiv thaiv nucleophilic hloov pauv.
Daim duab 01: Ib Nucleophilic Addition Reaction
Muaj lwm hom tshuaj tiv thaiv uas nucleophiles tuaj yeem pib; peb hu nws nucleophilic tshem tawm cov tshuaj tiv thaiv. Nucleophilicity qhia txog cov tshuaj tiv thaiv mechanisms; yog li, nws yog ib qho qhia txog cov tshuaj tiv thaiv. Piv txwv li, yog tias cov nucleophilicity siab, ces qee qhov kev tshwm sim sai sai, thiab yog tias cov nucleophilicity tsawg, cov tshuaj tiv thaiv qeeb. Txij li thaum nucleophiles pub electrons, raws li Lewis txhais, lawv yog cov hauv paus.
Electrophile yog dab tsi?
Electrophiles yog cov tshuaj reagents, uas nyob rau hauv lawv cov tshuaj tiv thaiv nrhiav cov electrons ntxiv uas yuav ua rau lawv muaj lub plhaub ruaj khov ntawm cov hluav taws xob. Carbocations yog electrophiles. Lawv tsis muaj hluav taws xob thiab tsuas muaj rau lub tshuab hluav taws xob hauv lawv lub plhaub valence. Vim li no, carbocations tuaj yeem ua raws li Lewis acids. Lawv tau txais ib khub electron los ntawm nucleophile thiab sau lub plhaub valence.
Daim duab 02: Ib qho Kev Sib Txuas Ntxiv Hluav Taws Xob
Electrophiles tej zaum yuav muaj tus nqi zoo, ib feem ntawm tus nqi zoo, lossis lub plhaub ntawm lub ntsej muag nrog lub octet tsis tiav. Electrophilic hloov pauv thiab electrophilic ntxiv cov tshuaj tiv thaiv yog ob qhov kev cuam tshuam loj uas electrophiles tuaj yeem pib. Nyob rau hauv ib qho kev hloov pauv cov tshuaj tiv thaiv electrophilic, ib qho electrophile displaces ib atom los yog pab pawg neeg nyob rau hauv ib tug compound. Peb tuaj yeem pom qhov xwm txheej no feem ntau hauv cov tshuaj tsw qab. Piv txwv li, qhov no yog cov txheej txheem nrog ib pawg nitro txuas rau lub nplhaib benzene los ntawm kev hloov cov hydrogen. Hauv cov tshuaj tiv thaiv electrophilic ntxiv, pi daim ntawv cog lus nyob rau hauv ib lub molecule tawg thiab ib daim ntawv cog lus tshiab ntawm cov molecule thiab electrophile.
Qhov txawv ntawm Nucleophile thiab Electrophile yog dab tsi?
A nucleophile yog ib qho tsis zoo ion lossis ib qho nruab nrab molecule uas muaj tsawg kawg yog ib qho tsis sib koom electron khub thaum cov electrophiles yog reagents, uas nyob rau hauv lawv cov kev xav nrhiav cov electrons ntxiv uas yuav muab lawv lub plhaub ruaj khov ntawm electrons. Yog li, qhov sib txawv tseem ceeb ntawm nucleophile thiab electrophile yog qhov nucleophile yog ib yam khoom uas nrhiav qhov chaw zoo thaum cov electrophiles nrhiav qhov chaw tsis zoo uas muaj cov hluav taws xob ntxiv. Ntxiv mus, peb tuaj yeem xav txog nucleophiles li Lewis bases thaum electrophiles li Lewis acids. Li no, qhov no yog lwm qhov sib txawv ntawm nucleophile thiab electrophile.
Cov hauv qab no infographic tabulates qhov sib txawv ntawm nucleophile thiab electrophile raws li ib sab ntawm kev sib piv.
Summary – Nucleophile vs Electrophile
Nucleophiles thiab electrophiles yog ob hom tshuaj sib txawv uas muaj peev xwm pib ua cov tshuaj sib txawv. Qhov sib txawv tseem ceeb ntawm nucleophile thiab electrophile yog qhov nucleophile yog ib yam khoom uas nrhiav qhov chaw zoo thaum lub electrophiles nrhiav qhov chaw tsis zoo uas muaj cov hluav taws xob ntxiv.
