Qhov sib txawv tseem ceeb ntawm ketone thiab ester yog tias ketone muaj cov pab pawg ua haujlwm carbonyl thaum ester muaj cov carboxylic acid ua haujlwm.
Ketones thiab esters yog cov organic tebchaw uas sib txawv ntawm ib leeg raws li pab pawg ua haujlwm uas lawv muaj. Tsis tas li ntawd, qhov sib txawv tseem ceeb ntawm ketone thiab ester yog lawv cov ntxhiab tsw. Qhov tsis hnov tsw ntawm ketones yog pungent thaum ester tsw yog ib tug fruity tsw. Muaj qee qhov sib txawv thiab, uas tau piav qhia hauv kab lus no.
Ketone yog dab tsi?
Ketone yog ib pawg ntawm cov organic tebchaw uas muaj pawg carbonyl txuas nrog ob pawg alkyl lossis aryl. Yog li, cov qauv tshuaj siv dav dav yog RC (=O) R'. Nyob ntawd, R thiab R' yog pawg muaj cov pa roj carbon. Ketones thiab aldehydes yog cov muaj feem xyuam nrog cov organic tebchaw uas muaj cov pab pawg carbonyl, tab sis ketone txawv ntawm ib qho aldehyde vim aldehyde muaj ib pawg alkyl lossis aryl thiab hydrogen atom txuas nrog pawg carbonyl.
Daim duab 01: Cov qauv dav dav ntawm Ketone
Nyob rau hauv lub npe ntawm ketone, pawg carbonyl tau muab tus lej (peb yuav tsum suav cov ketone los ntawm lub davhlau ya nyob twg uas ze tshaj rau pawg carbonyl). Yog li, ketone lub npe los ntawm kev hloov cov lus ntawm niam txiv alkane los ntawm -ane rau -anone. Piv txwv li, ib ketone muaj peb carbon atoms thiab ib pawg carbonyl ntawm lub thib ob carbon atom yog hu ua 2-propanone.
Thaum xav txog cov pa roj carbon atom ntawm pawg carbonyl, nws yog sp2 hybridized. Yog li ntawd, ketones yooj yim muaj trigonal planar geometry. Tsis tas li ntawd, qhov sib xyaw no yog polar vim muaj C=O daim ntawv cog lus. Ntxiv mus, ketones ua raws li nucleophiles ntawm oxygen atom (ntawm carbonyl pawg) thiab ua raws li electrophiles ntawm carbon atom (ntawm carbonyl pawg). Tsis tas li ntawd, lawv tuaj yeem tsim hydrogen bonds nrog dej molecules los ntawm ib leeg electron khub ntawm oxygen atom.
Kev tsim cov Ketone
Hauv kev tsim cov ketones rau kev lag luam, peb siv cov oxidation ntawm hydrocarbons hauv huab cua. i.e. acetone ntau lawm ntawm huab cua-oxidation ntawm cumene. Tab sis, rau cov ntawv tshwj xeeb, peb tuaj yeem siv ketones ntawm oxidation ntawm cov cawv thib ob. Tsis tas li ntawd, muaj ntau txoj hauv kev suav nrog, germinal halide hydrolysis, hydration ntawm alkynes, thiab, ozonolysis.
Ester yog dab tsi?
Ib qho ester yog cov organic compound uas muaj ob pawg alkyl lossis aryl txuas rau pawg carboxylic. Yog li ntawd, cov qauv dav dav ntawm ester yog RCO 2 R′. Ib qho ester tsim thaum hydrogen atom ntawm carboxylic acid hloov nrog ib pawg alkyl lossis aryl. Peb tuaj yeem tau txais esters los ntawm cov carboxylic acids lossis cawv.
Daim duab 02: Cov qauv dav dav ntawm Ester
Nyob rau hauv lub npe ntawm ib qho ester, ib qho chaw tau txais nws lub npe raws li lub npe ntawm niam txiv compound (cawv lossis carboxylic acid). Hauv lub npe ntawm ester, peb siv lub ntsiab lus -oate. Nws muaj ob lo lus nyob rau hauv nws lub npe, uas muab lub npe ntawm alkyl (los yog aryl) pawg txuas nrog cov pa atom ntawm carboxylic acid functional pawg ua raws li lub npe ntawm alkyl pab pawg neeg txuas nrog cov pa roj carbon atom ntawm pab pawg neeg ua haujlwm (nrog rau - oate suffix). Piv txwv li, methyl methanoate muaj ob pawg methyl txuas nrog rau pawg ua haujlwm ntawm ob sab.
Thaum xav txog cov khoom ntawm esters, esters muaj ntau dua polar dua ethers tab sis tsawg dua polar dua cawv. Ntxiv mus, lawv tuaj yeem koom nrog hydrogen bonding; Yog li, lawv yog me ntsis dej soluble. Lawv yog cov volatile dua li carboxylic acids ntawm tib qhov hnyav.
Esters yog cov khoom hauv cov txiv hmab txiv ntoo uas muaj lub luag haujlwm rau cov txiv hmab txiv ntoo aroma. Cov txiv hmab txiv ntoo uas muaj esters muaj xws li txiv apples, durian, pineapple, pears, strawberry, thiab lwm yam. Tsis tas li ntawd, cov rog hauv peb lub cev yog triesters tau los ntawm glycerol thiab fatty acid. Tsis tas li ntawd, esters tseem ceeb heev rau kev tsim cov acrylate esters, cellulose acetate, thiab lwm yam.
Kev tsim khoom ntawm Ester
Peb tuaj yeem tsim cov esters siv ntau txoj hauv kev, txoj hauv kev tseem ceeb tshaj plaws yog esterification ntawm carboxylic acids nrog cawv. Ntawm no, peb yuav tsum kho carboxylic acid nrog cawv nyob rau hauv lub xub ntiag ntawm ib tug dehydrating neeg sawv cev. Ntxiv mus, peb tuaj yeem tsim cov tshuaj no los ntawm esterification ntawm carboxylic acids nrog epoxides, alkylation ntawm carboxylate ntsev, carbonylation, thiab lwm yam.
Qhov txawv ntawm Ketone thiab Ester yog dab tsi?
Ketone yog ib pawg ntawm cov organic tebchaw uas muaj pawg carbonyl txuas nrog ob pawg alkyl lossis aryl. Ib qho ester yog cov organic compound uas muaj ob pawg alkyl lossis aryl txuas rau pawg carboxylic. Li no, qhov sib txawv tseem ceeb ntawm ketone thiab ester yog tias ketone muaj cov pab pawg ua haujlwm carbonyl thaum ester muaj cov carboxylic acid ua haujlwm.
Tsis tas li ntawd, cov qauv dav dav ntawm ketone yog RC(=O)R' thiab rau ester nws yog RCO2R'. Thaum xav txog qhov polarity, esters muaj ntau dua polar dua li ketones, thiab lawv yog cov volatile ntau thiab. Yog li, peb tuaj yeem xav txog qhov no ib yam li qhov sib txawv ntawm ketone thiab ester. Ntxiv mus, lawv cov ntxhiab tsw tshwj xeeb yog qhov sib txawv yooj yim ntawm ketone thiab ester. Tsis tas li ntawd, kev tsim cov ketones tuaj yeem ua tiav los ntawm oxidation ntawm hydrocarbons hauv huab cua thaum tsim cov esters tuaj yeem ua tiav ntawm esterification ntawm carboxylic acids nrog cawv.
Cov ntaub ntawv hauv qab no-daim duab qhia ntau qhov sib piv txog qhov txawv ntawm ketone thiab ester.
Summary – Ketone vs Ester
Ketones thiab esters yog cov organic tebchaw. Lawv txawv ntawm ib leeg raws li cov pab pawg ua haujlwm uas lawv muaj. Li no, qhov sib txawv tseem ceeb ntawm ketone thiab ester yog tias ketone muaj cov pab pawg ua haujlwm carbonyl thaum ester muaj cov carboxylic acid ua haujlwm.
