Ketones: chemical izakhiwo kanye nokuzimisela

i-chemistry Organic - isayensi luyindida kakhulu, kodwa ezithakazelisayo. Ngenxa compounds izici ofanayo inombolo ehlukile ukulandelana kanye Akhuthaza ukwakheka kwe ezahlukene izinto izakhiwo. Ake sicabangele lesi sithako iqembu carbonyl ngokuthi "ketones" (chemical izakhiwo, ubunjalo bomzimba, izindlela zamagama abo). Futhi eziqhathanisa namanye izinto sohlobo olufanayo - aldehydes.

ketones

Leli gama yigama elijwayelekile elisho isigaba bemvelo organic izidakamizwa, molecule lapho iqembu carbonyl (C = O) ixhunyaniswe carbon ezizivelelayo ezimbili.

Ngokusho isakhiwo yayo efana aldehydes ketones futhi acid carboxylic. Nokho, zikhona ngesikhathi esisodwa athomu amabili C (carbon noma i-carbon) exhunywe kwi C = O.

ifomula

Ifomula jikelele salokhu ikilasi compounds simiswe ngalendlela lelandzelako: R ₁ -CO-R _2.

Ukuze wenze uliqonde kangcono, njengoba umthetho, kulotshiwe kanjalo.

It C = O - kuyinto iqembu carbonyl. _{A-1 no-R} R ₂ - a ezizivelelayo carbon. Endaweni yabo kungaba compounds ezahlukene, kodwa ukuqanjwa kwawo kumele kube i-carbon.

Aldehydes futhi ketones

Izakhiwo kanye amakhemikhali la amaqembu izinto iyafana komunye nomunye. Ngenxa yalesi sizathu, avame kubhekwa ndawonye.

Iqiniso ukuthi aldehydes aqukethe iqembu carbonyl e-molecule awo ahlangane. Baze nge ketones formula ayefana kakhulu. Nokho, uma izinto C = O enamathiselwe ezizivelelayo ezimbili ke aldehyde ingenye kuphela, esikhundleni yesibili - of hydrogen athomu: R-CO-H.

Njengoba isibonelo, ifomula alesi sigaba izidakamizwa - formaldehyde nakakhulu njengoba formalin.

Kususelwa ifomula CH ₂ O, ubonakala ukuthi carbonyl iqembu layo ongakaphathelani eyodwa kodwa athomu amabili N.

izakhiwo

Ngaphambi esibhekana ngayo izakhiwo amakhemikhali aldehydes futhi ketones, kufanele ucabangele izici zabo ezingokwenyama.

• Ketones - a eziqinile ephansi encibilika noma uketshezi nge simo esishubile. Amalungu engezansi lesi sigaba siphela ngokuphelele H ₂ O futhi asabela ngayo kahle ezihogelwayo.
  abameleli ngamunye (isib CH ₃ COCH ₃₎ ngokuphawulekayo oncibilikayo emanzini, futhi ngokuphelele kunoma iyiphi enkulu.
  Ngokungafani alcohols futhi acid carboxylic, ketones abe simo esishubile okukhulu ne isisindo yamangqamuzana efanayo. Lokhu kunomthelela ukungakwazi lezi zakhi ukudala uxhumano H, njengoba kungase kube H-CO-R.
• Imihlobo ehlukeneko aldehydes kungaba ezifundeni ezihlukahlukene wokuhlanganisa. Njengoba ephakeme R-CO-H - kuba ukudla okuqinile zingaxazululeki. Lower - uketshezi, ingxenye yalo ixubene H esihle ₂ O, kodwa nje ezinye zazo zingabantu oncibilikayo emanzini, kodwa engasekho.
  Indlela elula yalolu hlobo izinto - aldehyde formic - gas okuyinto engavamile iphunga okunoshukela. Lokhu kwaziswa kahle oncibilikayo H ₂ O.

I ketones kunazo owaziwa

Kukhona izinto eziningi R ₁ -CO-R _{2 Nokho,} owaziwa wabo akuzona okungaka. Lena ngokuyinhloko dimethyl ketone, okuyinto sonke siyazi njengoba acetone. Futhi uzakwabo kuphela - butanone noma njengoba ubizwa ngokuthi kahle - methylethylketone.

Phakathi kwezinye ketones, amakhemikhali izakhiwo iziphi kabanzi obusetshenziswa embonini - acetophenone (metilfenilketon). Ngokungafani acetone futhi butanone, iphunga elimnandi ngempela, yingakho-ke isetshenziswa kwamakha.

Ngokwesibonelo, cyclohexanone iphathelene abameleli ejwayelekile R ₁ -CO-R _2, futhi kuvame kakhulu ukuba kusetshenziswe emsebenzini wokukhiqiza imithi yokususa ingcekeza elenkani.

Ingasaphathwa diketones. isihloko ezinjalo R ₁ -CO-R _2, lapho, hhayi kanye kodwa amaqembu amabili carbonyl e kwengoma. Ngakho, ifomula yabo: R ₁ -CO-CO-R _2. Omunye kakhulu elula, kodwa ngokuvamile usetshenziselwa ukwenza umkhakha ukudla abameleli diketones, diacetyl (2,3-butanedione).

Lezi izinto - ke nje uhlu encane ososayensi kwemiqondo ketones (property chemical zichaziwe ngezansi). Eqinisweni, kunezinhlobo ezingaphezu, kodwa hhayi zonke izicelo ezitholakele. Lapho-ke kuhle ukucabangela ukuthi abaningi babo bangabantu anobuthi.

I izakhiwo amakhemikhali ketones

Izinto kwalesi sigaba bayakwazi ukuxubana izinto ezihlukahlukene. Lokhu yikho ekhethekile amakhemikhali izakhiwo zabo.

• Ketones bayakwazi bazihlanganise H (hydrogenation ukuphendula). Nokho, i-umkhiqizo okunjena kudinga khona catalysts ngesimo ama-athomu metal nickel, ayibe, Cuprum, platinum, palladium, nabanye. Ukusabela R ₁ -CO-R ₂ nokuguquguquka ukuba alcohols yesibili.
  Futhi, ngokuphuza ukusabela e khona hydrogenous alikhali ziyinhlanganisela metal noma MG glycols etholakala ketones.
• Ketones kokuba okungenani ne-athomu elilodwa-alpha-hydrogenic bathambekele ziwela ngaphansi kwethonya keto-enol tautomerization. It is catalyzed hhayi kuphela esebenzisa acid, kodwa futhi izisekelo. Ngokuvamile, ifomu keto iyona mkhuba uzinze ngokwabo kuka enol. Lokhu yakhoibrium kwenza kube nokwenzeka synthesize le ketones ngu hydrating alkynes. sinjalo enol-keto Isihlobo amafomu we conjugation kuholela asidi R kunalokho eqinile ₁ -CO-R ₂ (uma iqhathaniswa alkanes).
• Lezi izinto ongangena yokusabela-ammonia. Noma kunjalo, zenzeka kancane kakhulu.
• Ketones ukuxubana hydrocyanic acid. Lokhu kuphumela α-oksinitrily, saponification egqugquzela nesenzakalo α-hydroxyacids.
• Ukungena ukuxubana halides alkylmagnesium kuholela ekwakhekeni alcohols yesibili.
• Ukujoyina NaHSO ₃ kunomthelela gidrosulfitnyh (bisulfite) nemikhiqizo. Kubalulekile nokukhumbula ukuthi ukusabela uchungechunge okunamafutha bayakwazi kuphela ukungena methyl ketones.
  Ngaphezu ketones, efana ukuxubana sodium hydrosulphite futhi kwangathi aldehydes.
  Lapho ukufuthelana nge isixazululo of NaHCO ₃ (soda baking) noma i-asidi amaminerali, amagama ahlobene of NaHSO ₃ angase ukubola ephelezelwa ukukhululwa kwe ketone khulula.
• Phakathi ukuphendula, R ₁ -CO-R ₂ nge NH ₂ OH (hydroxylamine) kanye ketoximes kwakhiwa njengoba ovela eceleni - H ₂ O.
• Ngo ukusabela ezihilela hydrazine kwakhiwa hydrazones (isilinganiso lomcebo kuhlanganiswe - 1: 1) noma azines (1: 2).
  Uma wathola ngenxa umkhiqizo yokusabela (hydrazone) ngaphansi kwethonya lokushisa bazothini potassium hydroxide, futhi N ume ematisa. Le nqubo ibizwa ngokuthi Kishner ukuphendula.
• Njengoba sekushiwo ngenhla, aldehydes futhi ketones nezakhi ezithile zamakhemikhali futhi ube efanayo eyamukelayo inqubo. acetals Ngakho R ₁ -CO-R ₂ ifomu uyinkimbinkimbi kakhulu kunalokho acetals R-CO-H. Babonakala ngenxa ketones ukuba esters futhi orthoformic orthosilicic acid.
• Ezindaweni ne lokuhlala ephakeme ka alkalis (isib ngokubeka amalahle ne H₂SO₄ kanzulu) R ₁ -CO-R ₂ waquliswa amanzi emzimbeni aphakathi ukwakha ketones unsaturated.
• Uma ukusabela nge R ₁ -CO-R ₂ iqukethe alikhali, ketones ibhekane aldol ukufingqa. Ngenxa yalokho, lo kwakhiwa β-keto alcohols ukuthi kalula ulahlekelwe molecule H ₂ O.
• Izimo zethu zihluke kakhulu abalulekile chemical izakhiwo azibonakalisa Isibonelo ketones acetone wasithukuthelela mesityl oxide. Esimweni esinjalo, a impahla entsha ebizwa nge "phorone".
• Futhi izakhiwo amakhemikhali izidakamizwa organic zihlanganisa Leuckart-Wallach ukuphendula, okuyinto enomthelela nokwehlisa ketones.

Ngenxa ukunikeza u-R1-CO-R2

Njengoba bazijwayeze izakhiwo izinto okukhulunywa, kubalulekile ukwazi izindlela ezivame kakhulu zamagama abo.

• Omunye ukusabela kunazo owaziwa ukulungiswa ketones iyona alkylation futhi acylation lezithako ezinuka kamnandi ebukhoneni yelikhono esidi (AlCl _3, FeCI _3, acid yezimbiwa, oxides, seka exchange inhlaka, nokunye okunjalo). Le ndlela ibizwa ngokuthi Friedel-yezandla ukuphendula ezaziwayo.
• Ketones kuthiwa kuhlelwe umqondo ngu hydrolysis ketimines futhi vic-diol. Endabeni le yokugcina kudinga khona acid yezimbiwa kulethe.
• Iphinde isetshenziselwe ukukhiqiza ketones homolog hydration acetylene noma njengoba ibizwa - ukusabela Kucherov.
• Ukusabela Guben-Gesha.
• Cyclization Ruzicka efanelekayo zamagama tsikloketonov.
• Futhi, idatha izidakamizwa misela kusukela peroksoefirov ephakeme usebenzisa Kriege rearrangement.
• Kukhona izindlela eziningana ukuze synthesis ketones ngesikhathi namachibi ukusabela alcohols yesibili. Kuye eselaphayo 4 ukusabela: Swern Kornblum, Corey-Kim futhi Parikh-Doering.

Ububanzi

Njengoba asebenzelana ngayo nezakhi ezithile zamakhemikhali akhiqize ketones kufanele wazi lapho lezi zinto nazo asetshenziswa.

Njengoba kushiwo ngenhla, iningi labo obusetshenziswa embonini zamakhemikhali kumakhemikhali awuketshezi ngoba lacquers, enamels, kanye ekukhiqizeni polymers.

Ngaphezu kwalokho, ezinye R ₁ -CO-R ₂ kahle kungase kutholakale njengoba flavorings. Ngenxa yalokho, ketones (benzophenone, acetophenone, njll) asetshenziswa kwamakha nokupheka.

Futhi acetophenone esetshenziswa njengoba isakhi ukwenziwa amaphilisi elele.

Benzophenone, ngenxa yekhono layo ukuze bachayeke emisebeni yelanga elimazayo - mbewu ezivamile izimonyo antizagarnoy kanyekanye uyalondoloza.

Inomthelela-R1-CO-R2 emzimbeni

Ukufunda ukuthi compounds ngokuthi ketones (chemical izakhiwo, isicelo, zamagama, nenye idatha ngazo), kubalulekile ukuba bajwayelane nezici begazi lezi izinto. Ngamanye amazwi, ukwazi ukuthi balandela izinto eziphilayo.

Naphezu ukusetshenziswa sasivumela kaningi R ₁ -CO-R ₂ embonini, kubalulekile njalo ukukhumbula ukuthi compounds enjalo anobuthi kakhulu. Abaningi babo umdlavuza futhi mutagenic.

kwabameleli abakhethekile bayakwazi ngalesi siyingi kubangele ubuhlungu ukuze nolwelwesi lwamafinyila, kuze ukusha. Alicyclic R ₁ -CO-R ₂ kungawuthinta umzimba efana izidakamizwa.

Nokho, akubona bonke izinto zalolu hlobo ziyingozi. Iqiniso lokuthi abanye babo bahileleke umzimba eziphilayo begazi.

Ketones - a amathokheni iziyaluyalu carbon umzimba insulini ukuntula esiyingqayizivele. Esikhathini ukuhlaziya umchamo futhi igazi khona R ₁ -CO-R ₂ kubonisa kwempilo umzimba, ezihlanganisa Hyperglycemia futhi ketoacidosis.