Qhov Tseem Ceeb - Achiral vs Meso
Qhov sib txawv tseem ceeb ntawm achiral thiab meso yog tias achiral compounds tsis muaj cov chaw chiral whereas meso compounds muaj ntau lub chaw chiral.
Ib lub chaw chiral yog cov pa roj carbon atom hauv cov organic molecule uas muaj plaub qhov sib txawv sib txawv txuas rau nws. Nyob rau hauv lwm yam lus, lub xub ntiag ntawm ib tug chiral center nyob rau hauv ib tug molecule qhia tias lub molecule tsis muaj symmetrical sab ntawm lub chiral center.
Achiral yog dab tsi?
Lo lus achiral txhais tau tias "tsis muaj chiral chaw nyob". Lub chaw chiral yog cov pa roj carbon atom ntawm cov organic compound uas muaj plaub qhov sib txawv sib txawv txuas rau nws. Yog li ntawd, ib tug chiral compound tsis muaj symmetry. Txawm li cas los xij, nws muaj daim iav uas tsis yog superimposable. Txij li thaum tsis muaj chiral chaw hauv achiral compounds, ib qho achiral compound muaj cov duab iav superimposable.
Daim duab 01: Piv txwv li, Methanol yog ib qho achiral molecule
Muaj ib lub dav hlau ntawm symmetry nyob rau hauv achiral compound. Hauv lwm lo lus, ib qho achiral faib ua ob qho tib si ib nrab ntawm ib lub dav hlau hu ua lub dav hlau ntawm symmetry. Txawm li cas los xij, nws yog lub dav hlau hypothetical. Ob lub symmetrical halves tau los ntawm lub dav hlau ntawm symmetry yog superimposable daim iav duab ntawm ib leeg; nyob rau hauv lwm yam lus, ib nrab qhia rau lwm ib nrab. Tsis zoo li chiral molecule, ib qho achiral molecule muaj ob lossis ntau qhov sib npaug sib npaug txuas rau lub chaw carbon. Ib qho achiral compound muaj peb yam tseem ceeb:
- Muaj tsawg kawg ib lub dav hlau ntawm symmetry
- Ib qho taw qhia ntawm kev hloov pauv (ib qho taw qhia ntawm cov molecule uas tuaj yeem siv los tig sab laug ntawm lub dav hlau sib luag los ntawm 180 okom tau sab xis ntawm cov molecule).
- Kev muaj ob daim ntawv cog lus lossis triple daim ntawv cog lus.
Meso yog dab tsi?
Lub sij hawm meso npe ib pawg ntawm cov organic molecules. Meso compound muaj ntau lub chaw chiral. Qhov no txhais tau hais tias ib qho meso compound muaj ob lossis ntau dua carbon atoms uas muaj plaub qhov sib txawv sib txawv. Cov tshuaj meso no kuj qhia cov khoom uas yog nruab nrab rau chiral thiab achiral compounds. Piv txwv li, meso tebchaw muaj chiral chaw (raws li nyob rau hauv chiral molecules), thiab daim iav duab ntawm ib tug meso compound yog superimposable nrog cov compound (raws li nyob rau hauv achiral compounds).
Daim duab 02: Ib qho meso compound uas muaj ob lub chaw chiral thiab ib lub dav hlau ntawm symmetry nrog rau daim iav superimposable.
Ib qho meso feem ntau muaj ob lossis ntau lub chaw chiral. Tab sis ib qho meso compound yog optically inactive, tsis zoo li chiral compounds, uas yog optically active. Yuav kom paub meej, optically inactive txhais tau hais tias ib qho meso compound tsis tuaj yeem tig lub dav hlau-polarized teeb. Meso compounds muaj peb yam tseem ceeb raws li qhia hauv qab no:
- Ua ntej, meso compounds muaj ob lossis ntau lub chaw chiral
- Secondly, meso tebchaw muaj ib lub dav hlau symmetrical (uas tuaj yeem muab ob qhov zoo ib yam ntawm cov molecule)
- Thib peb, kev sib hloov clockwise thiab anticlockwise kev sib hloov ntawm cov compound muab tib lub mis molecular (nyob ntawm daim iav superimposable dluab)
Dab tsi yog qhov zoo sib xws ntawm Achiral thiab Meso?
- Ob daim ntawv achiral thiab meso muaj lub dav hlau ntawm symmetry uas muab cov halves zoo tib yam.
- Ob leeg achiral thiab meso daim iav superimposable duab.
Qhov txawv ntawm Achiral thiab Meso yog dab tsi?
Achiral vs Meso |
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| lo lus achiral txhais tau tias tsis muaj chaw zov me nyuam. | lo lus meso txhais tau tias muaj ntau lub chaw chiral tam sim no. |
| Chiral Centers | |
| Tsis muaj chiral chaw hauv achiral compounds, tsis zoo li hauv cov tshuaj meso. | Muaj ob lossis ntau lub chaw chiral hauv meso compounds, tsis zoo li hauv achiral compounds. |
| Txoj kev Inversion | |
| Achiral compounds muaj qhov taw tes ntawm kev hloov pauv. | Tsis muaj qhov chaw inversion hauv meso compounds. |
Summary – Achiral vs Meso
Ob nqe lus achiral thiab meso piav qhia cov organic tebchaw. Lub chiral compound yog ib qho molecule uas muaj cov pa roj carbon atom txuas rau plaub qhov sib txawv. Qhov sib txawv tseem ceeb ntawm cov ntsiab lus achiral thiab meso yog tias achiral compounds tsis muaj chiral centre hos meso tebchaw muaj ntau lub chaw chiral. Hauv cov ntsiab lus, ib qho achiral compound yog qhov sib txawv ntawm chiral compound.
