Cov organic tebchaw uas yooj yim tshaj plaws yog saturated thiab unsaturated hydrocarbons. Cov no suav nrog cov khoom ntawm chav kawm ntawm alkanes, alkynes, alkenes.
Lawv cov qauv suav nrog hydrogen thiab carbon atoms nyob rau hauv ib ntu thiab ntau. Lawv feem ntau pom hauv qhov xwm txheej.
Kev txiav txim siab ntawm alkenes
Lawv lub npe yog olefins lossis ethylene hydrocarbons. Qhov ntawd yog qhov chav kawm ntawm cov tebchaw no tau hu ua nyob rau xyoo pua 18th thaum cov kua roj, ethylene chloride, tau tshawb pom.
Alkenes yog cov khoom uas muaj hydrogen thiab carbon ntsiab lus. Lawv yog cov acyclic hydrocarbons. Lawv cov molecule muaj ib qho ob npaug (unsaturated) daim ntawv cog lus txuas ob lub atoms rau ib leeg.
Alkene formulas
Txhua chav kawm ntawm cov tshuaj muaj nws tus kheej tsim tshuaj. Nyob rau hauv lawv, cov cim ntawm lub ntsiab ntawm lub periodic system qhia cov muaj pes tsawg leeg thiab cov qauv ntawm cov bonds ntawm txhua yam khoom.
Cov qauv dav dav ntawm alkenes yog qhia raws li hauv qab no: CH2n, qhov twg tus naj npawb n ntau dua lossis sib npaug 2. Thaum txiav txim siab nws, nws pom tau tias muaj ob lub hydrogen atoms rau txhua lub atom.
Molecular formulas ntawm alkenes los ntawm homologous series yog sawv cev los ntawm cov qauv hauv qab no: C2H4, C3 H6, C4H8, C 5H10, C6H12, C 7H14,8H16, C 9 H18,10H20. Nws tuaj yeem pom tias txhua qhov hydrocarbon txuas ntxiv muaj ib qho ntxiv carbon thiab 2 ntau hydrogen.
Nws muaj cov duab kos duab ntawm qhov chaw thiab kev txiav txim ntawm cov tshuaj sib txuas ntawm cov atoms hauv cov molecule, uas qhia cov qauv qauv ntawm alkenes. Nrog kev pab los ntawm valence kab, daim ntawv cog lus ntawm carbons nrog hydrogens yog qhia.
Cov qauv qauv ntawm alkenes tuaj yeem nthuav tawm hauv daim ntawv nthuav dav, thaum pom tag nrho cov tshuaj thiab cov ntawv cog lus. Nrog rau kev qhia meej ntxiv ntawm olefins, kev sib xyaw ntawm carbon thiab hydrogen nrog kev pab ntawm valence dashes tsis pom.
Cov qauv cev pob txha qhia txog cov qauv yooj yim tshaj plaws. Ib txoj kab tawg qhia txog lub hauv paus ntawm cov molecule, uas cov pa roj carbon atoms sawv cev los ntawm nws cov saum thiab xaus, thiab hydrogen yog qhia los ntawm kev sib txuas.
Yuav ua li cas cov npe olefin tsim
Raws li cov txheej txheem nomenclature, cov qauv ntawm alkenes thiab lawv cov npe yog tsim los ntawm cov qauv ntawm alkanes ntsig txog cov dej saturated hydrocarbons. Ua li no, nyob rau hauv lub npe ntawm lub tom kawg, lub ntsiab lus -an yog hloov los ntawm -ilen los yog -en. Ib qho piv txwv yog tsim ntawm butylene los ntawmbutane, thiab pentene los ntawm pentane.
Txhawm rau qhia txoj haujlwm ntawm ob daim ntawv cog lus txheeb ze rau carbon atoms, qhia tus lej Arabic tom kawg ntawm lub npe.
Alkenes muaj npe tom qab hydrocarbon nrog cov saw ntev tshaj plaws uas muaj ob daim ntawv cog lus. Rau qhov pib ntawm tus lej ntawm cov saw hlau, qhov kawg feem ntau yog xaiv, uas yog ze tshaj rau qhov tsis muaj qhov sib xyaw ntawm carbon atoms.
Yog tias cov qauv qauv ntawm alkenes muaj ceg, ces qhia cov npe ntawm cov radicals thiab lawv tus lej, thiab lawv ua ntej los ntawm cov lej sib raug rau qhov chaw hauv cov saw hlau. Tom qab ntawd ua raws li lub npe ntawm hydrocarbon nws tus kheej. Cov lej feem ntau yog ua raws li tus lej.
Muaj cov ceg tsis muaj kev txwv. Lawv cov npe tej zaum yuav tsis tseem ceeb los yog tsim raws li cov cai ntawm lub npe hu ua systematic nomenclature.
Piv txwv li, HHC=CH- hu ua ethenyl lossis vinyl.
Isomers
Molecular qauv ntawm alkenes tsis tuaj yeem qhia isomerism. Txawm li cas los xij, rau cov khoom siv hauv chav kawm no, tshwj tsis yog cov ethylene molecule, kev hloov kho spatial yog inherent.
Isomers ntawm ethylene hydrocarbons tuaj yeem yog cov pob txha pob txha, los ntawm txoj haujlwm ntawm cov nyiaj tsis txaus ntseeg, interclass lossis spatial.
Cov qauv dav dav ntawm alkenes txiav txim siab cov pa roj carbon thiab hydrogen atoms hauv cov saw hlau, tab sis nws tsis qhia qhov muaj thiab qhov chaw ntawm ob daim ntawv cog lus. Ib qho piv txwv yog cyclopropane ua interclass isomer ntawm C3H6 (propylene). Lwm hom isomerism tshwm sim hauv C4H8 lossisbutene.
Txoj haujlwm sib txawv ntawm daim ntawv cog lus tsis txaus ntseeg tau pom hauv butene-1 lossis butene-2, hauv thawj qhov xwm txheej, ob qhov sib xyaw nyob ze ntawm thawj carbon atom, thiab hauv qhov thib ob - hauv nruab nrab ntawm cov saw hlau. Isomerism hauv cov pob txha pob txha tuaj yeem txiav txim siab siv qhov piv txwv ntawm methylpropene) thiab isobutylene ((CH3)2C=CH2).
Kev hloov kho qhov chaw yog qhov muaj nyob rau hauv butene-2 hauv trans- thiab cis-txoj hauj lwm. Nyob rau hauv thawj rooj plaub, sab radicals nyob rau saum toj thiab hauv qab ntawm lub ntsiab carbon saw nrog ib tug ob daim ntawv cog lus, nyob rau hauv lub thib ob isomer, lub substituents nyob rau tib sab.
Olefin characterization
Cov qauv dav dav ntawm alkenes txiav txim siab lub cev ntawm txhua tus neeg sawv cev ntawm chav kawm no. Pib nrog ethylene thiab xaus nrog butylene (los ntawm C2 mus rau C4), cov tshuaj muaj nyob hauv daim ntawv gaseous. Yog li tsis muaj xim ethene muaj ntxhiab tsw qab, solubility tsawg hauv dej, molecular hnyav tsawg dua li huab cua.
Hauv daim ntawv ua kua, hydrocarbons ntawm homologous ntau ntawm C 5 rau C17 tau nthuav tawm. Pib los ntawm cov alkene, uas muaj 18 carbon atoms nyob rau hauv cov saw tseem ceeb, kev hloov ntawm lub cev lub cev mus rau cov ntaub ntawv khoom tshwm sim.
Tag nrho cov olefins raug suav hais tias muaj cov dej tsis zoo hauv cov dej nruab nrab, tab sis zoo solubility hauv cov kuab tshuaj organic, xws li benzene lossis roj av. Lawv qhov hnyav molecular tsawg dua li cov dej. Kev nce hauv cov saw hlau ua rau qhov ntsuas kub nce ntxiv thaum lub sij hawm melting thiab boiling ntawm cov tebchaw.
Properties of olefins
qauv qauv ntawm alkenesqhia tau hais tias muaj nyob rau hauv lub cev pob txha ntawm ob daim ntawv cog lus ntawm π- thiab σ-compound ntawm ob carbon atoms. Cov qauv no ntawm cov molecule txiav txim siab nws cov khoom siv tshuaj. Lub π-bond yog suav tias yog tsis muaj zog heev, uas ua rau nws muaj peev xwm ua kom puas nws nrog kev tsim ntawm ob tug tshiab σ-bonds, uas tau txais los ntawm qhov sib ntxiv ntawm ib khub ntawm atoms. Unsaturated hydrocarbons yog cov khoom siv hluav taws xob. Lawv koom nrog cov txheej txheem ntxiv electrophilic.
Ib qho tshuaj tseem ceeb ntawm tag nrho cov alkenes yog cov txheej txheem ntawm halogenation nrog kev tso tawm ntawm cov tebchaw zoo ib yam li dihalogen derivatives. Halogen atoms muaj peev xwm txuas ntawm ob daim ntawv cog lus rau carbons. Ib qho piv txwv yog bromination ntawm propylene nrog tsim ntawm 1, 2-dibromopropane:
H2C=CH–CH3 + Br2 → BrCH 2–CHBr–CH3.
Cov txheej txheem ntawm cov xim neutralization hauv dej bromine nrog alkenes yog suav tias yog cov pov thawj zoo ntawm qhov muaj ob daim ntawv cog lus.
Cov tshuaj tiv thaiv tseem ceeb suav nrog hydrogenation ntawm olifins nrog ntxiv ntawm hydrogen molecule nyob rau hauv qhov kev txiav txim ntawm cov hlau catalytic xws li platinum, palladium lossis npib tsib xee. Qhov tshwm sim yog hydrocarbons nrog ib daim ntawv cog lus saturated. Cov qauv ntawm alkanes, alkenes tau muab hauv qab no hauv cov tshuaj tiv thaiv butene hydrogenation:
CH3–CH2–CH=CH2 + H 2 Ni→ CH3–CH2–CH 2–CH3.
Cov txheej txheem ntawm kev ntxiv hydrogen halide molecule rau olefinsyog hu ua
hydrohalogenation, ua raws li txoj cai nrhiav pom los ntawm Markovnikov. Ib qho piv txwv yog hydrobromination ntawm propylene los ua 2-bromopropane. Hauv nws, hydrogen ua ke ntawm ob daim ntawv cog lus nrog carbon, uas yog suav tias yog hydrogenated tshaj plaws:
CH3–CH=CH2 + HBr → CH3–BrCH– CH3.
Cov tshuaj tiv thaiv ntawm cov dej ntxiv los ntawm alkenes hauv kev ua ntawm cov kua qaub yog hu ua hydration. Qhov tshwm sim yog ib qho molecule ntawm cawv propanol-2:
CH3–HC=CH2 + H2O → CH 3–OHCH–CH3.
Thaum raug alkenes nrog sulfuric acid, txheej txheem ntawm sulfonation tshwm sim:
CH3–HC=CH2 + HO−OSO−OH → CH3 –CH3CH–O-SO2-OH.
Cov tshuaj tiv thaiv pib nrog kev tsim cov kua qaub esters, piv txwv li, isopropylsulfuric acid.
Alkenes raug oxidation thaum lawv combustion nyob rau hauv qhov kev txiav txim ntawm oxygen los tsim dej thiab carbon dioxide gas:
2CH3–HC=CH2 + 9O2 → 6CO 2 + 6H2O.
Kev sib cuam tshuam ntawm olefinic tebchaw thiab dilute poov tshuaj permanganate hauv daim ntawv ntawm cov tshuaj ua rau tsim glycols lossis dihydric cawv. Cov tshuaj tiv thaiv no kuj yog oxidative, ua ethylene glycol thiab discoloring cov tshuaj:
3H2C=CH2 + 4H2O+ 2KMnO 4 → 3OHCH–CHOH+ 2MnO2 +2KOH.
Alken molecules tuaj yeem koom nrog hauv txheej txheem polymerization nrog cov dawb radicallos yog cation-anion mechanism. Nyob rau hauv thawj rooj plaub, nyob rau hauv tus ntawm peroxides, ib tug polymer xws li polyethylene yog tau.
Raws li lub tshuab thib ob, cov kua qaub ua cationic catalysts, thiab organometallic tshuaj yog anionic catalysts nrog tso tawm ntawm ib tug stereoselective polymer.
Dab tsi yog alkanes
Lawv tseem hu ua paraffins lossis saturated acyclic hydrocarbons. Lawv muaj ib tug linear los yog branched qauv, uas tsuas muaj saturated yooj yooj yim bonds. Txhua tus neeg sawv cev ntawm homological series ntawm chav kawm no muaj cov qauv dav dav C H 2n+2.
Lawv tsuas muaj cov pa roj carbon thiab hydrogen atoms xwb. Cov qauv dav dav rau alkenes yog tsim los ntawm kev tsim cov hydrocarbons saturated.
Npe ntawm alkanes thiab lawv cov yam ntxwv
Tus neeg sawv cev yooj yim tshaj plaws ntawm chav kawm no yog methane. Nws ua raws li cov khoom xws li ethane, propane thiab butane. Lawv lub npe yog nyob ntawm lub hauv paus ntawm tus lej hauv Greek, uas lub ntsiab lus -an ntxiv. Cov npe ntawm alkanes tau teev nyob rau hauv IUPAC nomenclature.
Cov mis loj ntawm alkenes, alkynes, alkanes tsuas muaj ob hom atoms xwb. Cov no suav nrog cov ntsiab lus carbon thiab hydrogen. Tus naj npawb ntawm carbon atoms nyob rau hauv tag nrho peb chav kawm yog tib yam, qhov sib txawv tsuas yog pom nyob rau hauv tus naj npawb ntawm hydrogen, uas yuav muab faib tawm los yog ntxiv. Unsaturated compounds yog tau los ntawm saturated hydrocarbons. Cov neeg sawv cev ntawm paraffins nyob rau hauv lub molecule muaj 2 ntau hydrogen atoms tshaj olefins, uas tau lees tiasGeneral formula ntawm alkanes, alkenes. Cov qauv alkene raug suav tias tsis muaj qhov tsis txaus vim muaj qhov sib npaug ntawm ob daim ntawv cog lus.
Yog tias peb txheeb cov lej ntawm hydrogen thiab carbon atoms hauv alkanes, ces tus nqi yuav siab tshaj plaws piv nrog rau lwm cov chav kawm ntawm hydrocarbons.
Los ntawm methane mus rau butane (los ntawm C1 rau C4), tshuaj muaj nyob rau hauv daim ntawv gaseous.
Hauv daim ntawv ua kua, hydrocarbons ntawm homologous ntau ntawm C 5 rau C16 tau nthuav tawm. Pib los ntawm alkane, uas muaj 17 carbon atoms nyob rau hauv cov saw tseem ceeb, kev hloov ntawm lub cev lub cev mus rau hauv cov ntaub ntawv khoom tshwm sim.
Lawv yog tus yam ntxwv los ntawm isomerism nyob rau hauv cov pa roj carbon skeleton thiab kev hloov kho qhov muag ntawm cov molecule.
Nyob rau hauv paraffins, carbon valences raug suav hais tias yog tag nrho los ntawm cov nyob sib ze carbons los yog hydrogens nrog tsim ntawm σ-type bonds. Los ntawm kev pom tshuaj, qhov no ua rau lawv cov khoom tsis muaj zog, uas yog vim li cas alkanes hu ua saturated lossis saturated hydrocarbons, tsis muaj kev sib raug zoo.
Lawv nkag mus rau hauv kev hloov pauv cuam tshuam nrog radical halogenation, sulfochlorination lossis nitration ntawm cov molecule.
Paraffins tau dhau los ua cov txheej txheem ntawm oxidation, combustion lossis decomposition ntawm qhov kub thiab txias. Nyob rau hauv qhov kev txiav txim ntawm cov tshuaj tiv thaiv accelerators, tshem tawm ntawm hydrogen atoms los yog dehydrogenation ntawm alkanes tshwm sim.
Dab tsi yog alkynes
Lawv kuj tseem hu ua acetylenic hydrocarbons, uas muaj peb daim ntawv cog lus hauv cov saw hlau. Cov qauv ntawm alkynes tau piav qhia los ntawm cov dav davformula CH2n–2. Nws qhia tau hais tias, tsis zoo li alkanes, acetylenic hydrocarbons tsis muaj plaub hydrogen atoms. Lawv raug hloov los ntawm ib daim ntawv cog lus triple tsim los ntawm ob π-compounds.
Cov qauv zoo li no txiav txim siab cov tshuaj lom neeg ntawm chav kawm no. Cov qauv qauv ntawm alkenes thiab alkynes kom meej meej qhia qhov tsis txaus ntawm lawv cov molecules, nrog rau qhov muaj ob npaug (H 2 C꞊CH2) thiab triple (HC≡CH) ties.
Npe ntawm alkynes thiab lawv cov yam ntxwv
Tus neeg sawv cev yooj yim tshaj plaws yog acetylene lossis HC≡CH. Nws tseem hu ua ethin. Nws los ntawm lub npe ntawm saturated hydrocarbon, nyob rau hauv uas lub ntsiab lus -an raug tshem tawm thiab -in yog ntxiv. Hauv cov npe ntev alkynes, tus lej qhia qhov chaw ntawm daim ntawv cog lus triple.
Paub txog cov qauv ntawm saturated thiab unsaturated hydrocarbons, nws muaj peev xwm txiav txim siab nyob rau hauv tsab ntawv twg cov qauv ntawm alkynes qhia: a) CnH2n; c) CnH2n+2; c) CnH2n-2; d) CnH2n-6. Lo lus teb raug yog qhov kev xaiv thib peb.
Los ntawm acetylene mus rau butane (los ntawm C 2 rau C 4), cov tshuaj yog gaseous hauv xwm.
Hauv cov kua dej muaj cov hydrocarbons ntawm homologous lub sijhawm los ntawm C 5 rau C17. Pib los ntawm alkyne, uas muaj 18 carbon atoms nyob rau hauv cov saw tseem ceeb, kev hloov ntawm lub cev lub cev mus rau cov ntaub ntawv khoom tshwm sim.
Lawv yog tus yam ntxwv los ntawm isomerism nyob rau hauv lub cev pob txha, nyob rau hauv txoj hauj lwm ntawm triple daim ntawv cog lus, nrog rau kev hloov pauv ntawm cov molecule.
poCov yam ntxwv tshuaj ntawm acetylenic hydrocarbons zoo ib yam li alkenes.
Yog tias alkynes muaj daim ntawv cog lus triple, ces lawv ua cov kua qaub nrog tsim cov ntsev alkynide, piv txwv li, NaC≡CNa. Lub xub ntiag ntawm ob π-bonds ua rau sodium acetyledine molecule muaj zog nucleophile uas nkag mus rau hauv kev hloov pauv.
Acetylene dhau chlorination nyob rau hauv lub xub ntiag ntawm tooj liab chloride kom tau dichloroacetylene, condensation nyob rau hauv qhov kev txiav txim ntawm haloalkynes nrog tso tawm ntawm diacetylene molecules.
Alkynes koom nrog cov tshuaj tiv thaiv electrophilic ntxiv, lub hauv paus ntsiab lus ntawm kev ua kom muaj halogenation, hydrohalogenation, hydration thiab carbonylation. Txawm li cas los xij, cov txheej txheem no ua haujlwm tsis muaj zog ntau dua li hauv alkenes nrog ob daim ntawv cog lus.
Rau acetylenic hydrocarbons, ntxiv cov tshuaj tiv thaiv ntawm nucleophilic hom molecule ntawm cawv, thawj amine lossis hydrogen sulfide yog ua tau.
