Ifomula jikelele yama-alkenes. Izakhiwo nezici zama-alkenes

Ama-organic compounds alula kakhulu yi-hydrocarbons esinqunyelwe futhi engasetshenzisiwe. Zihlanganisa izinto ze-alkanes ekilasini, ama- alkynes, ama-alkenes.

Amafomu abo afaka i-hydrogen ne-carbon athomu ngokulandelana nokulingana okuthile. Zivame ukutholakala emvelweni.

Incazelo ye-alkenes

Elinye igama yi-olefins noma i-ethylene hydrocarbons. Leli yigama laleli qembu lama-compounds ekhulwini le-18 lapho kutholakala uketshezi olunamafutha, u-ethylene chloride.

Ama-alkenes afaka izinto eziqukethe izinto eziphathelene ne-hydrogen ne-carbon. Zingabase-acyclic hydrocarbons. Emangqamuzaneni abo kukhona isibopho esisodwa esisodwa (unsaturated) esixhunyanise ama-athomu amabili e-carbon.

Amafomu we-alkenes

Isigaba ngasinye samakhemikhali sinamakhemikhali akhe. Kuzo, izimpawu zezingxenye zesistimu yezinkathi zesikhathi zikhombisa ukwakheka nesakhiwo sokuxhumeka kwemithi ngayinye.

Ifomula evamile yama-alkenes ichazwa kanje: C _n H _2n , lapho inomboro n inkulu kunazo zonke noma ilingana no-2. Uma ihlaziywa, kucacile ukuthi kune-athomu amabili e-hydrogen nge-carbon athomu.

Amafomula amakhemikhali ama-alkenes avela ochungechungeni lwama-homologous amelwa yizakhiwo ezilandelayo: C ₂ H ₄ , C ₃ H ₆ , C ₄ H ₈ , C ₅ H ₁₀ , C ₆ H ₁₂ , C ₇ H ₁₄ , C ₈ H ₁₆ , C ₉ H ₁₈ , C ₁₀ H ₂₀ . Kubonakala ukuthi i-hydrocarbon ngayinye elandelanayo iqukethe enye i-carbon kanye ne-hydrogen engaphezulu.

Kukhona ukucaciswa okucacile kwendawo kanye nokuhlelwa kwamakhemikhali amakhemikhali phakathi kwama-athomu ku-molecule, ekhombisa indlela yokwakhiwa kwama-alkenes. Ngesizo se-valence sidonsa uxhumano lwamathebhoni nge-hydrogen kuboniswa.

I-alkene formula structural formula ingaboniswa ifomu elandisiwe, lapho zonke izici zamakhemikhali nezibopho zikhonjiswa. Ngokuboniswa okuningiliziwe kwama-olefini, isibopho se-carbon-hydrogen asibonisi usebenzisa i-valence dashes.

Ifomula yamathambo ibonisa isakhiwo esilula. Umzila ophukile ubonisa isisekelo se-molecule lapho ama-athomu e-carbon amelelwa ngamasu ayo futhi aphela, futhi izixhumanisi zibonisa i-hydrogen.

Amagama ama-olefini asungulwa kanjani

Ukuqhubekela phambili ekuchazeni isiqephu esimisiwe, ama-alkene amafomula namagama abo akhiwe ngesakhiwo se-alkanes yama-hydrocarboni aphezulu. Ukwenza lokhu, egameni lesigxobo sokugcina -ngena esikhundleni se-oryl noma -ene. Isibonelo ukubunjwa kwe-butylene kusuka ku-butane, ne-pentene kusuka ku-pentane.

Ukuze ukhombise isikhundla sobudlelwane obubili ngokuphathelene nama-athomu e-carbon, bonisa isibalo sama-Arabhu ekupheleni kwegama.

Igama lama-alkenes lisekelwe ekudalweni kwe-hydrocarbon neketheni elide kunazo zonke, lapho kukhonjiswe kabili khona. Ukuphela kwenombolo yezinketho kuvame ukukhethwa, okuyinto esiseduze ne-unsaturated compound yamakhemikhali e-carbon.

Uma ifomu le-alkenes lendlela yokwakha linamagatsha, khona-ke ukhombise amagama ama-radicals nenombolo yabo, futhi ngaphambi kwabo bafake izinombolo ezihambelana nendawo ku-carbon chain. Khona-ke igama le-hydrocarbon lilandela. Ngemuva kwezinombolo ngokuvamile zibeka i-hyphen.

Kunamagatsha angama-radical angenayo. Amagama abo angaba amancane noma akhethwe ngokuvumelana nemithetho ye-nomenclature ehlelekile.

Isibonelo, i-HNS = CH- ibizwa i-ethenyl noma i-vinyl.

Isomers

Amafomula amakhemikhali ama-alkenes akakwazi ukukhombisa i-isomerism. Kodwa-ke, kulolu klasi lwezinto, ngaphandle kwe-molecule ye-ethylene, ukuguqulwa kwendawo kuyingxenye.

I-isomers yama-hydrocarbon e-ethylene ingaba eceleni kwe-carbon skeleton, isikhundla sezingxenyeni ezingekho ngaphansi kwe-insaturated, i-classic noma indawo.

Ifomula evamile yama-alkenes inquma inani le-athomu le-carbon ne-hydrogen elinezintambo, kodwa ayikhombisi ubukhona nendawo yokubopha kabili. Isibonelo i-cyclopropane njenge-classic isomero C ₃ H ₆ (propylene). Ezinye izinhlobo ze-isomerism zibonakala ku-C ₄ H ₈ noma i-butene.

Isikhundla esihlukile sesibambiso esingaxhunyiwe kubonakala ku-butene-1 noma i-butene-2, esimweni sokuqala i-compound kabili iseduze ne-athomu ye-carbon yokuqala, futhi okwesibili - phakathi kochungechunge. I-isomerism ye-carbon skeleton ingacatshangelwa isibonelo se-methyl propene (CH ₃ -C (CH ₃ ) = CH ₂ ) ne-isobutylene ((CH ₃ ) 2 C = CH ₂ ).

Ukuguqulwa kwendawo kufakwe ku-butene-2 endaweni yokudlulisela kanye ne-cis. Esikhathini sokuqala, ama-radicals ohlangothini atholakala phezulu nangaphansi kwe-carbon main chain nge-bond bond kabili, okwesibili i-substantents ihlangothini olufanayo.

Izinhlamvu zama-olefini

Ifomula jikelele yama-alkenes inquma isimo sangempela sabo bonke abamele isigaba esinikeziwe. Ukuqala nge-ethylene nokuphela nge-butylene (kusuka ku-C ₂ kuya ku-C ₄ ), izinto zikhona efomeni elimnandi. Ngakho i-ethene engenambala inephunga elimnandi, inhlanganisela encane emanzini, inqwaba yamangqamuzana engaphansi kweyomoya.

Esikhathini samafutha, ama-hydrocarboni wegegal homologous kusuka C ₅ kuya C ₁₇ amelelwe. Ukuqala nge-alkene enama-athomu angu-18 ku-carbon, isimo somzimba sishintsha ngendlela eqinile.

Wonke ama-olefini abhekwa njengabantu abampofu emaphephandabeni aqueous, kodwa okuhle kumakhemikhali endalo, ezifana ne-benzene noma i-petroli. Umthamo wabo wamangqamuzana ungaphansi kwamanzi. Ukwanda kwe-carbon chain kuholela ekwandeni kwezici zokushisa ngesikhathi sokuqhaqha nokubilisa kwalezi zinhlanganisela.

Izakhiwo zama-olefini

Umthamo wokwakhiwa kwama-alkenes ubonisa ukuba khona emasendeni okubophezela kabili kusukela π- and σ- amakhemikhali ama-athomu amabili. Lesi sakhiwo se-molecule senza amakhemikhali awo. Isibopho se-π singabhekwa njengamandla kakhulu, okwenza sikwazi ukuyibhubhisa ngokubunjwa kwezibopho ezimbili ezintsha-σ, ezitholakala ngenxa yokungezwa kwama-athomu amabili. Ama-hydrocarboni angasetshenzisiwe abanikeli be-electron. Bahlanganyela ezintweni zokujoyina i-electrophilic.

Impahla ebalulekile yamakhemikhali yawo wonke ama-alkenes yinqubo ye-halogenation, ngokuhlukaniswa kwamakhemikhali afana nezidakamizwa ze-dihalogen. Ama-athomu angama-halogen angahlanganiswa ngokubopha kabili ku-carbon. Isibonelo ukukhishwa kwe-propylene nokubunjwa kwe-1,2-dibromopropane:

H ₂ C = CH-CH ₃ + Br ₂ → BrCH ₂ -CHBr-CH ₃ .

Le nqubo yokungahambisani nombala emanzini e- bromine nama- alkenes kubhekwa njengesibonakaliso sokufaneleka sokuba khona kwesibopho esiphindwe kabili.

Ukusabela okubalulekile kuhlanganisa i-hydrogenation yama-oligine ngokufaka i-molecule ye-hydrogen ngaphansi kwesenzo sezinto ezinokwenziwa njenge-platinum, i-palladium noma i-nickel. Ngenxa yalokho, kutholakala ama-hydrocarboni anezibopho ezigcwele. Amafomu ama-alkanes, ama-alkenes anikezwa ngezansi ekuphenduleni kwe-hydrogenation kwe-butene:

CH ₃ -CH ₂ -CH = _{2 2} + H ₂ ^Ni → CH ₃ -CH ₂ -CH ₂ -CH ₃ .

Inqubo yokuhlanganisa i-hydrogen halide molecule kuya kuma-olefins ibizwa ngokuthi
Hydrohalogenation, edlula ngokuvumelana nomthetho otholakale uMarkovnikov. Isibonelo yi-hydrobromination propylene yokwakha i-2-bromopropane. Kulo, i-hydrogen ihlanganisa ukubopha kabili nekhabhoni, okubhekwa njengowokudonswa kwe-hydrogenated:

CH ₃ -CH = CH ₂ + HBr → CH ₃ -BCHCH-CH ₃ .

Ukuphendula kwe-alkene ukufaka amanzi ngaphansi kwesenzo se-acids kubizwa ngokuthi i-hydration. Ngenxa yalokho, kutholakala i- propanol-2 alcohol molecule:

CH ₃ -HC = CH ₂ + H ₂ O → CH ₃ -OHCH-CH ₃ .

Lapho evezwe ama-alkenes nge-sulfuric acid, inqubo yokwenza i-sulfonation yenzeka:

CH ₃ -HC = CH ₂ + HO-OSO-OH → CH ₃ -CH ₃ CH-O-SO ₂ -OH.

Ukusabela kudala ama-acid esters, isibonelo, i-isopropylsulfuric acid.

Ama-alkenes angenwa yi-oxidation ngesikhathi sokushisa kwawo ngesenzo se-oksijeni ngokubunjwa kwamanzi negesi lika-carbon dioxide:

2CH3-HC = CH2 + 9O2 → 6CO2 + 6H2O.

Ukusebenzisana kwamakhemikhali e-olefinic kanye ne-dilutedum potanganum permanganate ngendlela yesisombululo kuholela ekwakheni ama-glycols noma ama-diols wesakhiwo se-diatomic. Lokhu kusabela kubuye kube ne-oxidative ekubunjweni kwe-ethylene glycol kanye nokwehlukaniswa kwesisombululo:

3H ₂ C = CH ₂ + 4H ₂ O + 2KMnO ₄ → 3OHCH-CHOH + 2MnO ₂ + 2KOH.

Ama-molecule alken angabandakanyeka enqubeni ye-polymerization ngenqubo yamahhala e-radical noma cation-anion. Esikhathini sokuqala, ngaphansi kwethonya lama-peroxide, kutholakala i-polymer ye-polyethylene uhlobo.

Ngokwesigaba sesibili, ama-catalysts e-cationic ayimvelo, futhi izinto ze-anionic yizinto ze-organometallic ezihlukaniswa ne-polymeric stereoselective.

Yimaphi ama-alkan

Babizwa nangokuthi amapharafini noma ukunciphisa ama-acyclic hydrocarbon. Sinesakhiwo esivamile noma se-branched, esinezibopho ezilula kuphela ezigcwele. Bonke abamele lochungechunge lwe-homologous yalesi sifunda banenhlawulo jikelele C _n H _{2n + 2} .

Iqukethe kuphela ama-athomu e-carbon ne-hydrogen. Ifomula evamile yama-alkenes yakha kusukela ekudalweni kwama-hydrocarboni ekugcineni.

Amagama ama-alkan kanye nezici zazo

Ummeli olula weli klasi yi-methane. Kulandelwa izinto ezifana ne-ethane, i-propane ne-butane. Enhliziyweni yegama labo yimizi yezinombolo zesiGreki, lapho isixhumi-noma isinezelwa khona. Amagama ama-alkanes afakwe kuhlu lwe-IUPAC.

Ifomula jikelele yama-alkenes, ama-alkynes, ama-alkan ahlanganisa izinhlobo ezimbili kuphela zama-athomu. Lezi zihlanganisa izinto zekhabhoni ne-hydrogen. Inombolo ye-athomu ye-carbon kuwo wonke amakilasi amathathu afana, umehluko ubonakala kuphela emanzini e-hydrogen engakwazi ukuhlukanisa noma ukujoyina. Ama-hydrocarboni anelisiwe anika ama-unsaturated compounds. Ama-paraffin e-molecule aqukethe amanye ama-athomu ama-hydrogen amabili kune-olefins, okuqinisekiswa yi-formula jikelele yama-alkanes, ama-alkenes. Isakhiwo se-Alkenes siyabhekwa njenge-unsaturated ngenxa yobuningi bokubopha kabili.

Uma siqhathanisa inani lama-athomu e-hydrogen ne-carbon at alkanes, khona-ke inani lizobe likhulu uma kuqhathaniswa namanye amakilasi ama-hydrocarboni.

Ukuqala nge-methane nokuphela nge-butane (kusuka ku-C ₁ kuya ku-C ₄ ), izinto zikhona efomeni elibi.

Ama-hydrocarboni we-gog homologous kusuka ku-C ₅ kuya ku-C ₁₆ amelelwe efomini le-liquid. Ukuqala nge-alkane enama-athomu angu-17 e-carbon at the chain main, isimo somzimba sishintsha ngendlela eqinile.

Zibonakala nge-isomerism eceleni kwe-carbon skeleton nokuguqulwa kwe-optical kwe-molecule.

Emaphafini, i-carbon valence ithathwa ukuthi ihlale ihlala ngokugcwele ngesikhahla esakhelene noma i-hydrogen ukuze yenze isibopho se-σ. Kusuka endaweni yokubukeka kwamakhemikhali, lokhu kubangelwa izindawo zabo ezibuthakathaka, yingakho ama-alkanes abizwa ngokuthi ama-hydrocarboni agcwele noma agcwele, angenawo amakhemikhali.

Bafaka ukusabela kokufaka endaweni okuhlobene nokungaxhunyiwe okukhulu kwe-halogenation, i-sulfochlorination noma i-nitration ye-molecule.

Ama-paraffin asebenza ngokukhipha isisindo, ukushisa noma ukubola ekushiseni okuphezulu. Ngaphansi kokusebenza kwama-speed accelerators, ama-athomu e-hydrogen ahlukaniswa noma ama-alkan ayenziwa ngamanzi.

Ayini ama-alkynes

Zibizwa nangokuthi i-acetylene hydrocarbons, lapho kubanjwe khona isibopho kathathu ku-carbon chain. Isakhiwo sama-alkynes sichazwa ngefomula jikelele C _n H _{2 n-2} . Kubonisa ukuthi ngokungafani nama-alkanes, i-acetylene hydrocarbons ayikho ama-athomu amane e-hydrogen. Bashintshwa yisibopho esithathu esakhiwe yi-π-uxhumano ababili.

Lesi sakhiwo sinquma izindawo zamakhemikhali zalesi sifundo. Umthamo wokwakha ama-alkenes nama-alkynes ubonisa ngokucacile ukungaqothulwa kwama-molecule, kanye nokuba khona kwama-double (H ₂ C꞊CH ₂ ) nezibopho ezintathu (HC≡CH).

Igama lama-alkynes nezici zazo

Ummeleli olula kakhulu yi-acetylene noma i-HC≡CH. Kubizwa nangokuthi i-ethyne. Ivela egameni le-hydrocarbon egcwele, lapho isixhumi-noma isusiwe futhi -kungeziwe. Ngamagama ama-alkynes ende, isibalo sibonisa indawo yesibopho esithathu.

Ukwazi ukwakheka kwe-hydrocarbons egcwele futhi engasetshenzisiwe, kunokwenzeka ukunquma ngaphansi kweyiphi incwadi ifomu elijwayelekile le-alkynes elikhethiwe: a) CnH2n; C) i-CnH2n + 2; C) i-CnH2n-2; D) CnH2n-6. Impendulo efanele yindlela yesithathu.

Ukuqala nge-acetylene nokuphela nge-butane (kusuka ku-C ₂ kuya ku-C ₄ ), izinto ziyingozi emvelweni.

Esikhathini samafutha kukhona ama-hydrocarbons wegey homologous kusuka C ₅ kuya eC17. Ukuqala nge-alkyne enama-athomu angu-18 ku-carbon, isimo somzimba sishintsha ngendlela eqinile.

Zibonakaliswa yi-isomerism eceleni kwe-carbon skeleton, ngesimo sesibambiso sesithathu, futhi nangokuhlelwa kwe-classic ye-molecule.

Ngokwezimpawu zabo zamakhemikhali, ama-acetylene hydrocarbons afana nama-alkenes.

Uma i-alkyne inesibopho esithathu esibulalayo, khona-ke yenza njenge-asidi ukwenza ama-salts e-alkynides, isibonelo i-NaC≡CNa. Ukuba khona kwezibopho ezimbili ze-π kwenza i-acetylidine molecule ye-sodium i-nucleophile eqinile ekungeneni kokushintshwa.

I-Acetylene yenziwa ukuchithwa phambi kwe-chloride yethusi ukuthola i-dichloroacetylene, ukunciphisa ngaphansi kwesenzo se-haloalkynes nokuhlukaniswa kwama-molecular diacetylene.

Ama-alkine abamba iqhaza ekusebenziseni ukufaka ama-electrophilic, isimiso esisekelwe ku-halogenation, i-hydrohalogenation, i-hydrotreatment kanye ne-carbonylation. Noma kunjalo, izinqubo ezinjalo zibuthakathaka kunama-alkenes ne-bond bond kabili.

Ukuze uthole ama-hydrocarboni ase-acetylenic, ukusabela kokungezwa ngenhlobo ye-nucleophilic ye-molecule ye-alcohol, kungenzeka ukuthi i-amine oyinhloko noma i-hydrogen sulphide.