Vim tias cov carbocation xav tias lub hom phiaj, kev tawm tsam los ntawm nucleophile tuaj yeem tshwm sim los ntawm ob sab ntawm lub dav hlau. Qhov no ua rau kev tsim ntawm sib tov ntawm enantiomers, hu ua kev sib xyaw ntawm haiv neeg. Qhov no yog qhov sib piv rau SN2 uas tsuas yog tsim cov stereoisomer inverted ntawm cov reactant.
Qhov twg muab kev sib tw sib tw SN1 lossis SN2?
Cov carbocation thiab nws cov hloov pauv yog tag nrho nyob rau hauv tib lub dav hlau (Daim duab 1), txhais tau hais tias cov nucleophile tuaj yeem tawm tsam los ntawm ob sab. Raws li qhov tshwm sim, ob qho tib si enantiomers tau tsim nyob rau hauv ib qho SN1 cov tshuaj tiv thaiv, ua rau muaj kev sib tw sib tw ntawm ob qho tib si enantiomers.
Puas SN2 ua rau muaj kev sib tw?
Yog hais tias ib qho ntshiab enantiomer raug siv rau S N 2 cov tshuaj tiv thaiv, peb qhov sib txawv stereochemical tau pom tau: … Yog tias tuav thiab thim rov qab tshwm sim rau tib qib, cov tshuaj tiv thaiv yuav ua rau cov neeg sib tw sib tw(Racemization).
Yuav ua li cas cov tshuaj tiv thaiv ua ib haiv neeg sib xyaw?
Racemic mixes feem ntau tsim thaum achiral tshuaj hloov mus ua chiral ones Qhov no yog vim qhov tseeb tias chirality tsuas yog paub qhov txawv hauv ib puag ncig chiral. Cov tshuaj achiral nyob rau hauv ib puag ncig achiral tsis nyiam los tsim ib qho enantiomer dua lwm tus.
Puas racemization tshwm sim hauv SN1?
a) Kev ntxub ntxaug tshwm sim hauv SN1 cov tshuaj tiv thaiv txij li hauv SN1, ib pawg (puag / nucleophile) tawm tsam los ntawm ob sab.