Qhov sib txawv tseem ceeb ntawm chirality thiab helicity yog tias chirality yog hais txog cov cuab yeej ntawm asymmetry ntawm cov molecules uas tsis yog-superposable daim iav duab, whereas helicity yog hais txog cov cuab yeej ntawm asymmetry ntawm molecules muaj ib tug twisted 3D qauv.
Chirality thiab helicity yog ob nqe lus hauv kev siv stereogenic. Helicity tseem hu ua inherent chirality vim hais tias ob lo lus muaj feem cuam tshuam rau ib leeg.
Chirality yog dab tsi?
Chirality yog hais txog cov cuab yeej uas muaj daim iav superposable. Lo lus no feem ntau yog siv nrog cov organic tebchaw. Lub ntsiab lus uas txiav txim siab qhov muaj lossis tsis muaj chirality nyob rau hauv ib lub molecule yog lub chiral centre ntawm cov molecule. Chiral centre yog cov pa roj carbon atom ntawm cov organic compound uas muaj plaub qhov sib txawv sib txawv txuas rau nws. Chiral compounds yog cov tshuaj uas muaj chiral carbon atoms. Chirality yog qhov tseeb ntawm kev muaj chiral centres. Lub chaw chiral yog qhov tseem ceeb sp3 hybridized vim tias nws yuav tsum tau dais plaub pawg sib txawv ntawm cov atoms, tsim plaub daim ntawv cog lus ib leeg.
Daim duab 01: Ob Enantiomers ntawm Generic Amino Acid uas yog Chiral
Chiral chaw ua rau qhov muag pom isomerism ntawm cov tebchaw. Hauv lwm lo lus, cov tebchaw muaj cov chaw chiral tsis suav nrog nws daim iav duab. Yog li ntawd, lub compound uas muaj lub chiral centre thiab lub molecule uas zoo li nws daim iav duab yog ob lub tebchaw sib txawv. Ua ke, ob lub molecules no hu ua enantiomers.
Ntawm qhov tod tes, lo lus achiral txhais tau hais tias tsis muaj chiral chaw nyob. 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.
Muaj ib lub dav hlau ntawm symmetry nyob rau hauv achiral compound. Hauv lwm lo lus, achiral tuaj yeem faib ua ob qhov sib npaug 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 nruab nrab.
Hlub yog dab tsi?
Helicity yog cov cuab yeej ntawm kev sib tw, helical qauv. Qhov no tseem hu ua inherent chirality. Cov molecules uas qhia tias helicity yog asymmetric. Tab sis qhov asymmetry no tshwm sim tsis yog los ntawm chiral chaw lossis stereocenters, tab sis los ntawm cov qauv 3D twisted. Lub tswv yim no yog thawj zaug los ntawm tus kws tshawb fawb Volker Boehmer hauv xyoo 1994.
Daim duab 02: Helicene Structure
Qee zaum, peb tuaj yeem pom tias qee cov chiral molecules muaj lub dav hlau chirality lossis dav hlau hla uas cov molecule yog asymmetric. Ib yam li ntawd, qee cov molecules uas qhia tias muaj kev nyab xeeb muaj chirality axes. Cov axes no tshwm sim los ntawm lub axis ntawm qhov chaw ntawm lub molecule uas lub chirality nthuav tawm.
Qhov txawv ntawm Chirality thiab Helicity yog dab tsi?
Chirality thiab helicity yog ob nqe lus hauv kev siv stereogenic. Qhov sib txawv tseem ceeb ntawm chirality thiab helicity yog tias chirality yog hais txog cov cuab yeej ntawm asymmetry ntawm cov molecules uas tsis yog-superposable daim iav duab, whereas helicity yog hais txog cov cuab yeej ntawm asymmetry ntawm molecules muaj ib tug twisted 3D qauv. Ntxiv mus, chirality tshwm sim yog tshwm sim los ntawm lub xub ntiag ntawm ib tug chiral los yog lub tso suab chaw, ua rau qhov tshwm sim ntawm ib tug uas tsis yog-superposable daim iav duab, thaum helicity yog tshwm sim los ntawm lub xub ntiag ntawm ib tug twisted 3D qauv, ua rau qhov tshwm sim ntawm ib tug uas tsis yog-superposable. daim iav.
Hauv qab infographic qhia txog qhov sib txawv ntawm chirality thiab helicity.
Summary – Chirality vs Helicity
Chirality thiab helicity yog ob nqe lus hauv kev siv stereogenic. Qhov sib txawv tseem ceeb ntawm chirality thiab helicity yog tias chirality yog hais txog cov cuab yeej ntawm asymmetry ntawm cov molecules uas tsis yog-superposable daim iav duab, whereas helicity yog hais txog cov cuab yeej ntawm asymmetry ntawm molecules muaj ib tug twisted 3D qauv.
