Dab tsi yog qhov kev txiav txim ntawm nucleophilicity hauv cov kev xaiv hauv qab no? Piav: Alkoxides tsis muaj zog Nu– dua carbanion vim tias tsis zoo rau cov pa oxygen ruaj khov dua carbon. CH3CH2CH2O– nucleophilic, vim tsawg steric hindrance. Tus nqi tsis zoo yog nucleophilic ntau dua li qhov chaw ruaj khov.
Kev txiav txim ntawm nucleophilicity yog dab tsi?
Nkauj tawm tshiab nyob rau hauv lub rooj sib tham nucleophilicity (ib leeg pub dawb) C- > N- > O - > F- txij li kev nce electronegativity txo qis tus khub ib leeg. Nov yog tib qho kev txiav txim raws li qhov pib.
Qhov twg yog qhov kev txiav txim kom raug rau lub zog nucleophilic?
Vim li no, qhov kev txiav txim kom raug ntawm nucleophilicity ntawm cov muab yog: 2, 3, 1, 4, piv txwv li kev xaiv D. Lus Cim: Lub zog ntawm nucleophiles kuj nyob ntawm steric hindrance thiab cov qauv ntawm cov molecules. Qhov ntau qhov sib xyaw yog loj, qhov tsawg dua yuav yog qhov nucleophilicity.
Qhov twg hauv qab no yog qhov tseeb ntawm nucleophilicity F Cl Br?
Nyob rau hauv polar protic cov kuab tshuaj (xws li dej thiab cawv, ib qho hnyav nrog OH) nucleophilicity nce thaum koj nqis mus rau hauv lub rooj (F- < Cl- < Br- < I –). Hauv polar aprotic cov kuab tshuaj (xws li DMSO, acetone) qhov kev txiav txim yog thim rov qab, thiab cov nucleophiles tseem ceeb tshaj plaws kuj yog cov nucleophilic tshaj plaws. ( F- > Cl – > Br – > I –).
Koj txhais li cas los ntawm nucleophilicity?
A nucleophile yog hom tshuaj lom neeg uas pub ib khub electron rau ib qho electrophile los tsim cov tshuaj lom neeg nyob rau hauv kev sib raug zoo Tag nrho cov molecules lossis ions nrog ib khub dawb ntawm electrons lossis tsawg kawg yog ib daim ntawv cog lus pi tuaj yeem ua raws li nucleophiles. Vim hais tias nucleophiles pub electrons, lawv yog los ntawm txhais Lewis bases.
