Ketones: tshuaj zog thiab kev txiav txim

Organic Science News for KIDS - lub science yog heev tham, tab sis interesting. Vim hais tias tebchaw ntawm lub tib yam nyob rau hauv ib tug txawv ib theem zuj zus tooj thiab yeej txhawb lub tsim ntawm txawv tshuaj zog. Cia peb xav txog cov compound ib carbonyl pab pawg neeg hu ua "ketones" (tshuaj zog, lub cev tus yam ntxwv, txoj kev lawv synthesis). Thiab los sib piv lawv nrog rau lwm cov tshuaj ntawm tib hom - aldehydes.

ketones

Lo lus no yog ib lub npe rau ib chav kawm ntawv ntawm cov organic qhov xwm ntawm yam, molecules ntawm uas tus carbonyl pab pawg neeg (C = O) yog txuas mus rau ob carbon radicals.

Raws li nws cov qauv zoo li aldehydes ketones thiab carboxylic acids. Txawm li cas los, lawv yog tam sim no ib zaug ob C atoms (carbon los yog cov pa roj carbon) kev cob cog rua rau C = O.

mis

Cov kev mis rau cov hoob kawm no ntawm tebchaw yog raws li nram no: R ₁ -CO-R _2.

Yuav kom ua rau nws to taub, raws li ib tug txoj cai, nws yog sau li ntawd.

Nws C = O - yog ib tug carbonyl pab pawg neeg. A _{1 thiab} R R ₂ - ib tug carbon radicals. Nyob rau hauv lawv qhov chaw tej zaum yuav txawv tebchaw, tab sis lawv muaj pes tsawg leeg yuav tsum carbon.

Aldehydes thiab ketones

Lub cev thiab tshuaj thaj chaw ntawm cov pab pawg ntawm tshuaj yog heev uas zoo sib xws rau txhua tus lwm yam. Vim li no, lawv yog feem ntau los ua ke.

Lub fact tias cov aldehydes kuj muaj ib tug carbonyl pab pawg neeg nyob rau hauv lawv cov molecules. Lawv txawm nrog ketones ntawm lub mis zoo heev. Txawm li cas los, yog hais tias tus tshuaj C = O txuas mus rau ob radicals ces tus aldehyde tsuas yog ib, es tsis txhob ntawm lub thib ob - los ntawm Hydrogen atom: R-CO-H.

Raws li ib qho piv txwv, cov mis ntawm no hauv chav kawm ntawv ntawm tshuaj - formaldehyde, tag nrho cov ntau zoo kawg li raws li formalin.

Raws li cov mis CH ₂ O, nws yog pom hais tias nws cov carbonyl pab pawg neeg yog tsis txuam nrog ib tug tab sis nrog ob tug atoms N.

lub zog

Ua ntej peb yuav nrog cov tshuaj thaj chaw ntawm aldehydes thiab ketones, yuav tsum xav txog lawv lub cev nta.

• Ketones - ib tug tsawg-melting khib nyiab los yog kua nrog volatility. Lub sab mej zeej ntawm lub chav kawm ntawv txig yaj nyob rau hauv H ₂ O thiab reacted zoo nrog organic solvents.
  Cov neeg sawv cev (e.g. CH ₃ COCH ₃₎ remarkably soluble nyob rau hauv cov dej, thiab kiag li nyob rau hauv tej proportions.
  Nyob rau hauv sib piv rau lub alcohols thiab carboxylic acids, ketones muaj ib tug ntau dua volatility nrog tib molecular ceeb thawj. Qhov no muaj txhawb rau lub cev tsis muaj cov tebchaw los ua ib tug kev twb kev txuas nrog H, raws li tej zaum yuav H-CO-R.
• Ntau hom kev aldehydes yuav ua tau nyob rau hauv tej lub xeev ntawm aggregation. Txij li thaum dua R-CO-H - nws yog insoluble cov khib nyiab. Lower - ib tug ua kua, ib feem ntawm uas yog tov nrog zoo H ₂ O, tiam sis tsuas yog ib co ntawm lawv yog cov soluble nyob rau hauv dej, tab sis tsis muaj ntau.
  Qhov yooj yim ntawm no hom ntawm tshuaj - formic aldehyde - ib tug roj uas yog peculiar pungent tsw. Qhov no cov ntaub ntawv uas yog zoo soluble nyob rau hauv H ₂ O.

Qhov tseem zoo-paub ketones

Muaj ntau ntau yam r ₁ -CO-R _2, Txawm li cas los, zoo-paub ntawm lawv yog cov tsis heev npaum li cas. Qhov no yog feem ntau dimethyl ketone, uas peb txhua tus yeej paub li acetone. Tsis tas li ntawd nws colleague Hnyav - butanone los yog raws li nws yog zoo ib - methylethylketone.

Cov lwm ketones, tshuaj zog uas yog lug siv nyob rau hauv qhov kev lag luam - acetophenone (metilfenilketon). Tsis zoo li acetone thiab butanone, tus ntxhiab tsw yog heev qab ntxiag, uas yog vim li cas nws yog siv nyob rau hauv perfumery.

Piv txwv li, cyclohexanone koom raug cov neeg sawv cev R ₁ -CO-R _2, thiab yog feem ntau siv nyob rau hauv qhuav ntawm cov kuab tshuaj.

Tsis hais lub diketones. Xws li ib tug lub npe yog R ₁ -CO-R _2, nyob rau hauv uas tsis yog ib tiam sis ob carbonyl pawg nyob rau hauv muaj pes tsawg leeg. Yog li, lawv cov mis yog: R ₁ -CO-CO-R _2. Ib tug ntawm cov feem ntau yooj yim, tab sis feem ntau siv nyob rau hauv cov zaub mov kev lag luam yog cov neeg sawv cev diketones, diacetyl (2,3-butanedione).

Cov tshuaj - nws yog ib tug me me daim ntawv teev cov zaum tsim ketones (cov tshuaj zog yuav sib tham txog hauv qab no). Nyob rau hauv qhov tseeb, muaj ntau, tab sis tsis yog txhua txhua daim ntaub ntawv pom. Qhov ntau nws yog tsim nyog xav tias hais tias muaj ntau ntawm lawv yog cov tshuaj lom.

Cov tshuaj thaj chaw ntawm ketones

Tshuaj ntawm pawg no muaj peev xwm ua li cas nrog ntau yam tshuaj. Qhov no yog dab tsi yog lawv muab tshwj xeeb tshuaj zog.

• Ketones yuav tau muab lawv tus kheej rau H (hydrogenation cov tshuaj tiv thaiv). Txawm li cas los, qhov no cov tshuaj tiv thaiv cov khoom yuav tsum tau muaj ib tug catalyst nyob rau hauv daim ntawv ntawm hlau atoms ntawm npib tsib xee, cobalt, Cuprum, platinum, palladium, thiab lwm tus neeg. Cov tshuaj tiv thaiv R ₁ -CO-R ₂ evolve mus rau alcohols.
  Tsis tas li ntawd, los ntawm reacting nyob rau hauv lub xub ntiag ntawm ib tug hydrogenous alkali hlau hlau los yog Mg glycols yog tau los ntawm ketones.
• Ketones muaj tsawg kawg yog ib alpha-hydrogenic atom yuav poob nyob rau hauv tus ntawm keto-Enol tautomerization. Nws yog tshwmsim tsis tau tsuas yog los ntawm txoj kev acids, tab sis kuj tsim. Feem ntau, lub keto daim ntawv no yog cov paub ntau tshaj ruaj lawv tus kheej tshwm sim tshaj Enol. Qhov no equilibrium ua rau nws tau coj los ua ke rau hauv lub ketones los ntawm hydrating alkynes. Tus kwv tij stabilization Enol-keto ntaub ntawv ntawm qhov conjugation ua rau ib tug es muaj zog acidity R ₁ -CO-R ₂ (thaum piv rau alkanes).
• Cov tshuaj yuav tau nkag mus rau hauv ib lub tshuaj tiv thaiv uas ammonia. Txawm li cas los, lawv tshwm sim heev maj mam.
• Ketones hnov mob nrog hydrocyanic acid. Qhov no los tau nyob rau hauv α-oksinitrily, saponification uas txhawb nqa tshwm sim α-hydroxyacids.
• Nkag mus hnov mob nrog alkylmagnesium halides ua mus rau tsim ntawm ob alcohols.
• Koom NaHSO ₃ txhawb rau gidrosulfitnyh (bisulfite) derivatives. Nws yog ib nqi nco ntsoov tias nyob rau hauv cov tshuaj tiv thaiv nyob rau hauv lub fatty series yeej tsuas muaj mus nkag rau methyl ketones.
  Nyob rau hauv tas li ntawd mus ketones, zoo li hnov mob nrog sodium hydrosulphite thiab yuav aldehydes.
  Thaum rhuab nrog ib tug daws ntawm NaHCO ₃ (ci dej qab zib) los yog ib tug mineral acid, derivatives ntawm NaHSO ₃ tej zaum yuav decompose nrog qhov kev tso tawm ntawm dawb ketone.
• Thaum lub sij hawm cov tshuaj tiv thaiv, R ₁ -CO-R ₂ nrog NH ₂ OH (hydroxylamine) thiab ketoximes tsim raws li ib tug byproduct - H ₂ O.
• Nyob rau hauv tshua uas hydrazine tsim hydrazones (piv ntawm chav tshuaj - 1: 1) los yog azines (1: 2).
  Yog hais tias tus tau txais vim cov tshuaj tiv thaiv product (hydrazone) nyob rau hauv tus ntawm kub yuav hnov mob nrog poov tshuaj hydroxide, thiab N sawv saturates. Qhov no yog hu ua Kishner cov tshuaj tiv thaiv.
• Raws li twb hais saum toj no, aldehydes thiab ketones thiab tshuaj zog thiab muaj zoo xws li cov txais cov txheej txheem. Yog li acetals R ₁ -CO-R ₂ daim ntawv ntau dua acetals R-CO-H. Lawv tshwm sim raws li ib tug tshwm sim ntawm ketones rau esters thiab orthoformic orthosilicic acid.
• Nyob rau hauv tej kev kawm nrog ntau dua ntawm alkalis (e.g., los ntawm cua sov nrog concentrated H₂SO₄) R ₁ -CO-R ₂ yog raug rau ib tug intermolecular lub cev qhuav dej tsim unsaturated ketones.
• Yog hais tias ib tug tshuaj tiv thaiv uas R ₁ -CO-R ₂ muaj alkali, ketones yauv aldol hws. Li ntawd, cov tsim β-keto alcohols uas yuav yooj yim poob ib tug qauv ntawm H ₂ O.
• Heev tseem ceeb tshuaj zog manifest lawv tus kheej nyob rau hauv Piv txwv li ketones acetone reacted nrog mesityl oxide. Nyob rau hauv xws li ib tug cov ntaub ntawv, ib tug tshiab cov ntaub ntawv uas hu ua "phorone".
• Tsis tas li ntawd tshuaj thaj chaw ntawm cov organic tshuaj muaj xws li Leuckart-Wallach cov tshuaj tiv thaiv, uas muaj txhawb rau yuav txo tau ntawm ketones.

Vim muab R1-CO-R2

Thaum familiarized nrog lub zog ntawm cov tshuaj nyob rau hauv cov lus nug, nws yog tsim nyog los paub qhov feem ntau txoj kev rau lawv cov synthesis.

• Ib qho ntawm feem zoo-paub tshua rau qhov kev npaj ntawm ketones yog lub alkylation thiab acylation ntawm uas muaj ntxhiab tebchaw nyob rau hauv lub xub ntiag ntawm acidic catalysts (AlCl _3, FeCI _3, mineral acids, oxides, ntawv pauv resins, thiab cov zoo li). Qhov no yog hu ua tus Friedel-Crafts cov tshuaj tiv thaiv.
• Ketones yog tsim los ntawm hydrolysis ketimines thiab vic-diol. Nyob rau hauv cov ntaub ntawv ntawm lub caij nyoog kawg no yuav tsum tau muaj cov mineral acid raws li ib tug catalyst.
• Nws kuj yog siv los tsim ketones homolog ntawm acetylene co los yog raws li nws yog hu ua - qhov tshuaj tiv thaiv Kucherov.
• Tshua Guben-Gesha.
• Cyclization Ruzicka haum rau synthesis tsikloketonov.
• Tsis tas li ntawd, cov tshuaj yeeb dej caw cov ntaub ntawv mined los ntawm tertiary peroksoefirov siv Kriege rearrangement.
• Muaj ntau ntau txoj kev rau cov synthesis ntawm ketones thaum lub sij hawm oxidation tshua ntawm ob alcohols. Nyob rau hauv lub lub tebchaw yog 4 tshua: Swern Kornblum, Corey-Kim thiab Parikh-Doering.

Scope

Thaum hais txog nrog cov tshuaj zog thiab tsim ketones yuav tsum paub tias qhov twg cov tshuaj no kuj siv.

Raws li hais saum toj no, feem ntau ntawm lawv yog siv nyob rau hauv cov tshuaj raws li kev lag luam kuab tshuaj rau lacquers, enamels, raws li zoo raws li nyob rau hauv qhuav ntawm polymers.

Nyob rau hauv tas li ntawd, ib co R ₁ -CO-R ₂ zoo proven li flavorings. Raws li xws li, ketones (benzophenone, acetophenone, etc.) yog siv nyob rau hauv perfumery thiab ua noj ua haus.

Tsis tas li ntawd acetophenone siv raws li ib tug tivthaiv rau zus tau tej cov pw tsaug zog tshuaj.

Benzophenone, vim nws muaj peev xwm mus nqus teeb meem tawg - yog ib qho muaj nyob rau hauv tshuaj pleev ib ce thiab antizagarnoy ib txhij preservative.

Influences R1-CO-R2 rau lub cev

Tej hau kev kawm uas rau tebchaw hu ua ketones (tshuaj zog, daim ntawv thov, synthesis, thiab lwm yam ntaub ntawv hais txog lawv), nws yog tsim nyog mus ntsib nrog rau cov lom cov yam ntxwv ntawm cov tshuaj. Nyob rau hauv lwm yam lus, kom paub yuav ua li cas lawv ua rau muaj sia nyob.

Dua li ntawm qhov haum nquag siv ntawm R ₁ -CO-R ₂ nyob rau hauv kev ua lag luam, nws yog tsim nyog ib txwm nco ntsoov hais tias xws li tebchaw no mas lom. Muaj ntau ntawm lawv yog cov carcinogenic thiab mutagenic.

Tshwj xeeb cov neeg sawv cev yuav tau ua voos rau hauv txheej week, kom txog thaum kub yus. Alicyclic R ₁ -CO-R ₂ yuav cuam tshuam rau lub cev xws li cov tshuaj.

Txawm li cas los, tsis yog txhua txhua yam ntawm no hom muaj teeb meem. Lub fact tias ib txhia ntawm lawv muaj kev koom tes nyob rau hauv lub metabolism kev lom kab mob.

Ketones - ib tug tshwj xeeb tokens mob carbon metabolism thiab insulin tsis muaj peev xwm. Nyob rau hauv lub tsom xam ntawm cov zis thiab ntshav muaj cov R ₁ -CO-R ₂ qhia ntau yam metabolic mob, xws li hyperglycemia thiab ketoacidosis.