Qhov sib txawv tseem ceeb ntawm geminal thiab vicinal coupling yog tias geminal coupling yog hais txog kev sib txuas ntawm ob lub hydrogen atoms uas tau khi rau tib lub atom. Tab sis, vicinal coupling yog hais txog kev sib txuas ntawm ob lub hydrogen atoms uas khi rau ob lub atoms uas nyob ib sab.
Cov ntsiab lus geminal thiab vicinal coupling tuaj nyob rau hauv NMR (nuclear magnetic resonance) thiab lawv piav txog qhov sib txawv ntawm NMR peaks thaum hydrogen atoms undergo coupling txawv. Hydrogen atom coupling yuav tshwm sim ntawm ob lub hydrogen atoms uas khi rau tib lub atom los yog ob lub hydrogen atoms khi rau ob lub atoms uas nyob ib sab.
Dab tsi yog Geminal Coupling?
Geminal coupling yog qhov sib txuas ntawm ob lub atom hydrogen uas tau khi rau tib lub atom ntawm cov qauv sib xyaw. Txawm hais tias nws tsuas yog siv rau hydrogen atoms hauv NMR, lo lus geminal yog hais txog kev sib raug zoo ntawm ob pawg ua haujlwm lossis atoms uas txuas nrog tib lub atom. Piv txwv li, geminal diol hais txog ib qho cawv uas muaj ob pawg -OH txuas nrog tib lub atom.
Nyob rau hauv cov txheej txheem NMR, cov geminal coupling tsuas yog tshwm sim yog tias ob lub hydrogen atoms txuas rau ib pawg methylene sib txawv ntawm ib leeg stereochemically. Peb tuaj yeem pom geminal coupling li 2J. Qhov no txhais tau hais tias ob lub hydrogen atoms ob peb los ntawm ob daim ntawv cog lus tshuaj (ob daim ntawv cog lus ntawm hydrogen atoms thiab carbon atom). Lub geminal coupling kuj muaj tus nqi uas peb tuaj yeem hu ua geminal coupling tas li. Tus nqi ntawm qhov tas mus li no yuav txawv ntawm -23 txog +42 Hz, nyob ntawm lwm cov khoom siv uas txuas nrog tib lub atom.
Vicinal Coupling yog dab tsi?
Vicinal coupling yog hais txog kev sib txuas ntawm ob lub hydrogen atoms uas tau khi rau ob lub atoms uas nyob ib sab ntawm cov qauv compound. Lub sij hawm vicinal yog hais txog qhov txuas ntawm ob pawg ua haujlwm ntawm ob lub atoms uas nyob ib sab ntawm tib qho chaw. i.e. 2, 3-dibromobutane muaj ob lub bromine atoms txuas rau 2nd thiab 3rd carbon atoms ntawm ib tug butane molecule.
Txawm li cas los xij, hauv NMR spectroscopy, lo lus vicinal hais txog kev sib txuas ntawm ob lub atoms hydrogen uas txuas rau ob lub atoms uas nyob ib sab. Ntawm no, peb tuaj yeem txhais lo lus no ua 3J. Qhov no yog vim hais tias cov hydrogen atoms ob peb los ntawm peb chemical bonds (ob chemical bonds ntawm hydrogen atoms thiab carbon atoms ntxiv rau ib tug tshuaj bond ntawm ob carbon atoms). Peb tuaj yeem ntsuas qhov vicinal coupling hauv NMR raws li qhov sib txuas ntawm cov vicinal tas li, uas muaj tus nqi sib txawv ntawm 0 txog +20 HZ, nyob ntawm lwm cov khoom siv txuas nrog rau cov pa roj carbon atoms.
Qhov txawv ntawm Geminal thiab Vicinal Coupling yog dab tsi?
Cov ntsiab lus geminal coupling thiab vicinal coupling tuaj nyob rau hauv ceg ntawm NMR los yog nuclear magnetic resonance. Cov ntsiab lus no txawv ntawm ib leeg raws li cov qauv sib txuas ntawm hydrogen atoms hauv cov qauv sib xyaw. Qhov sib txawv tseem ceeb ntawm geminal thiab vicinal coupling yog tias geminal coupling yog hais txog kev sib txuas ntawm ob lub hydrogen atoms uas khi rau tib lub atom, hos vicinal coupling yog hais txog kev sib txuas ntawm ob lub hydrogen atoms uas yog khi rau ob lub atoms uas nyob ib sab.
Hauv qab infographic qhia ntau qhov sib piv ntsig txog qhov sib txawv ntawm geminal thiab vicinal coupling.
Summary – Geminal vs Vicinal Coupling
Cov ntsiab lus geminal coupling thiab vicinal coupling tuaj nyob rau hauv ceg ntawm NMR los yog nuclear magnetic resonance. Qhov sib txawv tseem ceeb ntawm geminal thiab vicinal coupling yog tias geminal coupling yog hais txog kev sib txuas ntawm ob lub hydrogen atoms uas khi rau tib lub atom. Meanwhile, vicinal coupling yog hais txog kev sib txuas ntawm ob lub hydrogen atoms uas khi rau ob lub atoms uas nyob ib sab.
