Kokubili ama-ketones nama-esters angamaqembu amabili abaluleke kakhulu ekusebenzeni kwamakhemikhali ezinto eziphilayo. Zitholakala ezinhlobonhlobo zenhlanganisela yezinto eziphilayo futhi zidlala indima ebalulekile ezinqubweni eziningi zezinto eziphilayo namakhemikhali. Naphezu kokufana kwazo, izici nokuziphatha kwazo kuhluke kakhulu. Ake sihlole ukuthi ayini ama-ketone nama-ester, ukuthi ahluke kanjani, afana kanjani, nokuthi asho ukuthini kukhemistry kanye ne-biology.
Ama-ketones yikilasi lezinhlanganisela eziphilayo eziqukethe iqembu elisebenzayo le-carbonyl (C=O) phakathi kwe-molecule. Ama-ketones anamaqembu amabili e-alkyl noma e-aryl axhunywe kukhabhoni ye-carbonyl. Okulula kakhulu kulezi yi-acetone, enefomula (CH3)2CO. Akhiqizwa ukuwohloka kwamafutha emzimbeni. Aziwa nangokuthi imizimba ye-ketone, ama-ketone angamakhemikhali akhiqizwa lapho umzimba wakho uqala ukuphula amafutha esikhundleni sama-carbohydrate ukuze uthole amandla.
Ama-ketone akhiwa ngama-fatty acids esibindini futhi adedelwa egazini, lapho angasetshenziswa khona njengomthombo wamandla kumaseli nezitho zomzimba. Lapho umzimba uku-ketosis, uthembele kuma-ketone njengomthombo wawo oyinhloko wamafutha, esikhundleni se-glucose, yingakho ukudla kwe-ketogenic kuye kwanda kakhulu eminyakeni yamuva. Kodwa-ke, ama-ketone awakhiqizwa kuphela ngesikhathi sokuzila ukudla noma ukudla kwe-ketogenic. Angabuye akhiqizwe lapho umzimba ucindezelekile, njengalapho uvivinya umzimba, noma lapho ukuntuleka kwe-insulin emzimbeni, okungenzeka kubantu abanesifo sikashukela.
Ama-ketones amathathu akhiqizwa ngesikhathi se-ketosis: i-acetone, i-acetoacetate, ne-beta-hydroxybutyrate (BHB). Phakathi kwazo, i-acetone iyi-ketone ekhishwa emzimbeni ngokuphefumula, ekhiqiza iphunga elimnandi noma elimnandi emphefumulweni, elivame ukubizwa ngokuthi "i-keto breath". Lokhu kungaba uphawu lokuthi umzimba wakho usungene esimweni se-ketosis. I-acetoacetate, enye i-ketone, ikhiqizwa esibindini futhi isetshenziswa amangqamuzana omzimba ukuze athole amandla. Kodwa-ke, iphinde iguqulele ku-BHB, uhlobo oluvame kakhulu lwe-ketone egazini ngesikhathi se-ketosis. I-BHB ingawela kalula umgoqo wegazi-ubuchopho, ngaleyo ndlela inikeze amandla ubuchopho futhi ingathuthukisa ukucaca kwengqondo nokugxila.
Ama-Ester ayizinhlanganisela eziphilayo ezinomsebenzi we-RCOOR, lapho u-R no-R' kungunoma yiliphi iqembu lezinto eziphilayo. Ama-Ester akhiwa lapho ama-carboxylic acid nama-alcohol esabela ngaphansi kwezimo ezine-asidi futhi eqeda i-molecule yamanzi. Zivame ukutholakala emafutheni abalulekile kanye nezithelo eziningi. Isibonelo, iphunga likabhanana ovuthiwe livela ku-ester ebizwa ngokuthi isoamyl acetate.Ama-Esters anezinto eziyingqayizivele eziwenza abe yigugu ezimbonini ezihlukahlukene.
1. Amakha
Okunye okuvamile ukusetshenziswa kwama-ester kumakha namakha ngenxa yephunga lawo elimnandi, eliyisithelo nelimnandi, futhi asiza ukuthuthukisa iphunga elimnandi lomkhiqizo, awenze uthandeke kakhulu kubasebenzisi.
2. Ukunambitheka kokudla
Isakhiwo samakhemikhali esiyingqayizivele sama-esters sibavumela ukuba banikeze iphunga elimnandi nezimbali, ngakho-ke ama-esters nawo asetshenziswa embonini yokudla, ikakhulukazi ekunambithekeni. Kuvame kakhulu ekudleni okuningi okuhlanganisa i-confectionery, izimpahla ezibhakiwe kanye neziphuzo. Ekuphileni kwansuku zonke, ama-esters asetshenziswe ekukhiqizeni ama-flavour okwenziwa futhi abe yizithako eziyisisekelo ekudleni okuningi.
3. Ipulasitiki
Njengama-plasticizers, ama-esters enza amapulasitiki aguquguquke futhi aqine. Ngakho-ke ama-esters asetshenziswa ekukhiqizeni amapulasitiki ahlukahlukene, futhi asiza futhi ukuvimbela amapulasitiki ukuthi abe brittle ngokuhamba kwesikhathi. Lokhu kubalulekile emikhiqizweni ehlala isikhathi eside njengezingxenye zezimoto noma izisetshenziswa zezokwelapha.
4. Ncibilikisa
Ngoba ama-esters angancibilikisa izinto eziphilayo ezinjengamafutha, ama-resin namafutha. Ngakho-ke, ama-esters awusizo ezimbonini eziningi njengezincibilikisi zokuncibilikisa ezinye izinto. Ama-Esters ama-solvents amahle, okwenza abe usizo ekukhiqizeni amapende, ama-varnishes nama-adhesives.
Ngokuqhathanisa ama-ketone nama-esters, singathola ukuthi umehluko phakathi kwama-ketone nama-esters ikakhulukazi kulezi zici ezilandelayo:
1. Umehluko omkhulu phakathi kwama-ketone nama-esters ikakhulukazi esakhiweni samakhemikhali. Iqembu le-carbonyl lama-ketone litholakala phakathi neketango lekhabhoni, kuyilapho iqembu le-carbonyl lama-esters litholakala ekugcineni kweketango lekhabhoni. Lo mehluko wesakhiwo uholela ekuhlukeni kwezakhiwo zabo zomzimba namakhemikhali.
●Ama-ketones ayizinhlanganisela eziphilayo ezineqembu le-carbonyl elihlanganisa i-athomu yomoya-mpilo ehlanganiswe kabili ku-athomu yekhabhoni etholakala maphakathi neketango lekhabhoni. Ifomula yabo yamakhemikhali ithi R-CO-R', lapho u-R no-R' kuyi-alkyl noma i-aryl. Ama-ketone akhiwa yi-oxidation yotshwala besibili noma ukuqhekeka kwe-carboxylic acid. Baphinde bathole i-keto-enol tautomerism, okusho ukuthi bangakhona kuzo zombili izinhlobo ze-ketone ne-enol. Ama-ketones avame ukusetshenziswa ekukhiqizeni izinyibilikisi, izinto ze-polymer kanye nemithi.
●Ama-Ester ayizinhlanganisela eziphilayo ezineqembu le-carbonyl ekugcineni kweketango lekhabhoni kanye neqembu elingu-R elixhunywe ku-athomu yomoya-mpilo. Ifomula yabo yamakhemikhali ithi R-COOR', lapho u-R no-R' kuyi-alkyl noma i-aryl. Ama-Esters akhiwa ukusabela kwama-carboxylic acid ane-alcohols phambi kwe-catalyst. Zinephunga elimnandi futhi zivame ukusetshenziselwa ukukhiqizwa kwamakha, ama-essences nama-plasticizers.
2.Umehluko osobala kakhulu phakathi kwama-ketone nama-esters yiphuzu lawo abilayo. Iphuzu lokubilisa lama-ketones liphakeme kunalelo lama-esters ngoba anamandla anamandla e-intermolecular. Iqembu le-carbonyl ku-ketone lingakha izibopho ze-hydrogen nama-molecule e-ketone aseduze, okuholela emandleni anamandla e-intermolecular. Ngokuphambene, ama-esters anamandla abuthakathaka e-intermolecular ngenxa yokungakwazi kwama-athomu omoya-mpilo eqenjini le-R ukwakha izibopho ze-hydrogen nama-molecule e-ester aseduze.
3.Ngaphezu kwalokho, ukusebenza kabusha kwama-ketone nama-esters kuhlukile. Ngenxa yokuba khona kwamaqembu amabili e-alkyl noma e-aryl nhlangothi zombili zeqembu le-carbonyl, ama-ketone asebenza kakhulu kune-esters. Lawa maqembu anganikela ngama-electron ku-carbonyl, okwenza kube lula ekuhlaselweni kwe-nucleophilic. Ngokuphambene, ama-esters awasebenzi kangako ngenxa yokuba khona kweqembu le-alkyl noma le-aryl ku-athomu ye-oxygen. Leli qembu linganikela ngama-electron ku-athomu yomoya-mpilo, lenze libe sengozini yokuhlaselwa yi-nucleophilic.
4. Ngenxa yezakhiwo ezahlukene, amaphuzu abilayo kanye nokusebenza kabusha kwama-ketone nama-ester, umehluko ekusetshenzisweni kwawo kunqunywa. Ama-ketones avame ukusetshenziswa ekukhiqizeni ama-solvents, izinto ze-polymer nezidakamizwa, kuyilapho ama-esters evame ukusetshenziswa ekukhiqizeni amakha, ama-flavour nama-plasticizers. Ama-ketones nawo asetshenziswa njengezithasiselo zikaphethiloli kuphethiloli, kuyilapho ama-ester asetshenziswa njengamafutha emishini.
Sesiyazi kakade imininingwane yama-ketone nama-esters, ngakho-ke uyini umehluko phakathi kwama-ketones, ama-esters kanye ne-ether?
Okokuqala, sidinga ukwazi ukuthi iyini i-ether? I-ether iqukethe i-athomu yomoya-mpilo ehlanganiswe nama-athomu ekhabhoni amabili. Ziyinhlanganisela eyaziwa ngezici zayo ze-narcotic. I-ether ngokuvamile ayinambala, iminyene kancane kunamanzi, futhi iyizincibilikisi ezinhle zezinye izinhlanganisela eziphilayo ezifana namafutha namafutha. Zibuye zisetshenziswe njengezithasiselo zikaphethiloli ezinjinini zikaphethiloli ukuze kuthuthukiswe ukusebenza kwezinjini.
Ngemva kokuqonda izakhiwo zamakhemikhali nokusetshenziswa kwalezi zintathu, singakwazi ngokucacile ukuthi umehluko phakathi kwama-ketone, ama-esters kanye ne-ether ahlanganisa izici ezimbili ezilandelayo:
1. Omunye umehluko ophawuleka kakhulu esingawuthola phakathi kwama-ketone, ama-ester, ne-ether amaqembu abo asebenzayo. Ama-ketones aqukethe amaqembu e-carbonyl, ama-ester aqukethe i-ester-COO- ukuxhumana, futhi ama-ether awaqukethe noma yimaphi amaqembu asebenzayo. Ama-ketones nama-esters abelana ngokufana okuthile kumakhemikhali amakhemikhali. Zombili izinhlanganisela ziyi-polar futhi zingakha izibopho ze-hydrogen namanye ama-molecule, kodwa izibopho ze-hydrogen kuma-ketone zinamandla kunalawo aku-ester, okuholela endaweni yokubilisa ephakeme.
2.Omunye umehluko obalulekile wukuthi lezi zintathu zinokusetshenziswa okuhlukene
(1)Enye yezindlela ezivame ukusetshenziswa kakhulu zama-ketone njenge-solvent yama-resin, ama-wax, namafutha. Zibuye zisetshenziswe ekukhiqizeni amakhemikhali amahle, imithi kanye namakhemikhali e-agrochemicals. Ama-ketones anjenge-acetone asetshenziswa ekukhiqizeni amapulasitiki, imicu nopende.
(2)Ama-Ester avame ukusetshenziswa ezimbonini zokudla nezimonyo ngenxa yephunga elimnandi nephunga elimnandi. Zibuye zisetshenziswe njengezincibilikisi zamayinki, ama-varnish nama-polymers. Ama-Esters nawo asetshenziswa ekukhiqizeni ama-resin, ama-plasticizers nama-surfactants.
(3)I-ether inezinhlobonhlobo zokusetshenziswa ngenxa yezakhiwo zayo ezihlukile. Zisetshenziswa njengama-solvents, ama-anesthetics nama-surfactants, phakathi kwabanye. Embonini yezolimo, asetshenziswa njengamafumigant ukuvikela izitshalo ezigciniwe ezinambuzaneni nasezifweni zefungal. I-ether iphinde isetshenziswe ekukhiqizeni ama-epoxy resins, ama-adhesives kanye nezinto zokugqoka.
Ama-ketones nama-ester anezicelo ezisabalele kukhemistri ephilayo futhi angamabhlokhi wokwakha wezinqubo eziningi zezimboni. Isibonelo, ama-ketones asetshenziswa njengama-solvents, ekukhiqizeni imithi nama-polymers. Ngakolunye uhlangothi, ama-ester asetshenziswa embonini yamakha nezimonyo, njengama-flavour embonini yokudla, njengama-solvents, nakumapende nama-cosmetics.
Isikhathi sokuthumela: Jun-14-2023
