Ukubunjwa, Imfundo Secondary nezikolo
Yintoni reactions okufana alkanes
Iklasi nganye iikhompawundi ngamachiza ukubonisa iipropati ngenxa nolwakhiwo elektroniki. Kuba alkanes ezithile endaweni reaction, cleavage okanye igcwala eziphilayo. Zonke iinkqubo yamachiza ane- flow yabo ethile, nto leyo eza kuxutyushwa ngakumbi.
Yintoni alkanes
Oku iikhompawundi hydrocarbon ifumile, ezaziwa ngokuba neparafini. Ezi molekyuli luqulathe kuphela carbon yehayidrojini athom, ngaba yomgama okanye branched ikhonkco acyclic apho kukho kuphela omnye ezimbaxa. Xa sijonga iimpawu iklasi, ungenza ntoni na indlela uphawu alkanes ukubala. Athobela Ifomula neklasi yonke: H 2n + 2 C n.
isakhiwo chemical
Iparafini molecule iquka athom carbon bembonisa sp 3 hybridization. Bonke orbitals ezine Valence akheke efanayo, amandla kunye nolwalathiso esithubeni. Ubungakanani engile phakathi kwamanqanaba amandla 109 ° 28 '.
Ubukho neentambo angatshatanga iimolekyuli imisela ukuba kuyinto uphawu alkanes. Bona ziqulathe σ-compound. Unxibelelwano phakathi carbons yi nonpolar kwaye okwanamhlanje polarizable, oko linamalungu kancinane C-H. Kwakhona, lexinene electron kwe nokutshintshela atom carbon yeyona electronegative. Umchiza ngenxa luphawulwa C-H wokwephuka elisezantsi.
kufakwe indlela
paraffins iklasi izinto kuba umsebenzi imichiza eliphantsi. Oku kunokucaciswa ngamandla ulwalamano phakathi C-C no C-H, nto leyo iqhawuka nzima ngenxa non-wokwephuka. Isiseko yenkxwaleko yabo yindlela homolytic, apho uhlobo ezamahala olukhulu ababandakanyekayo. Kungenxa yoko le nto alkanes luphawulwa yokusabela kufakwe. izinto ezifana bayakwazi ukuba basebenzisane molekyuli ngamanzi okanye bangane abathwali kwentlawulo.
Bona oluphezulu endaweni olukhulu simahla apho athom hydrogen athathelwa indawo izinto halogen okanye elinye iqela esebenzayo. Ezi zinto ziquka iinkqubo ezinxulumene halogenation, sulfochlorination kunye nitration. Ezi kukhokelela kumalungiselelo avela alkane.
- Inkqubo iqala nge esuthwini nucleation okanye ikhonkco, apho zezilwanya radicals simahla. Ezi ehlanganisa yimithombo ukukhanya yelanga kunye ubushushu.
- Bese andise chain apho amasuntswana alandelelanayo esebenzayo bamthwala intsebenziswano iimolekyuli baphola. Ukuguquka lwabo molecule radicals, ngokulandelelana kwazo.
- Inyathelo lokugqibela uya kuyiqhekeza chain. recombination Kukho okanye Ukunyamalala amasuntswana esebenzayo. Ngaloo ulwenze uphuhliso ukusabela chain.
Inkqubo halogenation
Oku kusekelwe indlela uhlobo olukhulu. Alkane halogenation reaction lwenzeka ngu zokukhanya kunye nokukhanya yelanga kunye zokufudumeza ngomxube halogens kunye hydrocarbon.
Zonke izigaba zenkqubo zixhomekeke kulawulo eyayisithi Markovnikov. Ithi xa ukhula endaweni ngu halogen, ingakumbi hydrogen, lalo le carbon hydrogenated. Halogenation kwenzeka kule ndlela ilandelayo: ukusuka lokuqala ukuya carbon atom ephakamileyo.
Le nkqubo ithatha indawo engcono iimolekyuli alkane kunye engundoqo chain hydrocarbon elide. Oku kubangelwa kukuhla kwamandla ionizing kweli cala, iyeza lula electron isisihla.
Umzekelo chlorination ngayo iimolekyuli methane. Isenzo kwemitha yelanga kubangela lwahlukane yeKhlorini iintlobo olukhulu ukuba enze uhlaselo phezu alkane. Ukwahlukana kwenzeka kwaye ukuyilwa atomic hydrogen H 3 C · okanye methyl olukhulu. Loo yamasuntswana, nayo, uwabulale wechlorine eziphilayo, okukhokelela ukutshatyalaliswa ubume bawo kwaye ukuyilwa lwekhemikhali entsha.
Kwinqanaba ngalinye lenkqubo endaweni wenziwa kuphela hydrogen atom enye. Le halogenation abasabela alkanes ekhokelela kuseko yokupasa hlormetanovoy, dichloromethane, kunye trihlormetanovoy tetrahlormetanovoy mpilo.
Ngokwalo, le nkqubo limi ngolu hlobo:
H 4 C + Cl: Cl → H 3 CCl + HCl,
H 3 CCl + Cl: Cl → H 2 CCl + 2 HCl,
H 2 CCl 2 + Cl: Cl → HCCl 3 + HCl,
HCCl 3 + Cl: Cl → CCl 4 + HCl.
Mu kuya kwa nshita chlorination neemolekyuli methane ethwele yenkqubo efana kunye namanye alkanes ebonakala ukufumana izinto ukuba hydrogen endaweni asilulo carbon atom, kwaye ezimbalwa. ratio lwabo ubuninzi ezinxulumene zalathisi lobushushu. Xa iimeko ebandayo, ukuhla kwesantya ukuyilwa avela kunye nesakhiwo ephakamileyo, lesibini nelokuqala.
Ngenxa yokwanda Isantya ekujoliswe lobushushu ukuyilwa iikhompawundi ezifana endaweni ephantsi. Kwinkqubo halogenation kukho impembelelo umba static leyo ibonisa amathuba ezahlukeneyo yokungqubana ngayo ngokugqibeleleyo kunye atom carbon.
Inkqubo halogenation iodine awufumaneki phantsi kweemeko eziqhelekileyo. Kuyimfuneko ukuba ukudala iimeko ezizodwa. Xa baboniswa methane kwenzeka ngokwentando halogen ukwenzeka hydrogen iodide. Kuye nefuthe imethyl iodide ngenxa ume ngaphandle reactants lokuqala methane kunye iodine. Loo yokusabela kuthathwa ukuba ingathityazwa.
Wurtz zisabela alkanes
Yindlela ukuze bafumane hydrocarbon kunye nesakhiwo ifumile macala. Njengoko reactants asetyenziswa sodium metal, bromides alkyl okanye kloride alkyl. Yabo intsebenziswano walungisa sodium halide kunye nokwanda ikhonkco ezizizembiwa yona sum of the radicals ezimbini hydrocarbon. Ngokwalo, lo kuyondelelaniswe imi ngolu hlobo lulandelayo: R-Cl + Cl-R + 2Na → R-R + 2NaCl.
Wurtz abasabela alkanes kunokwenzeka kuphela xa halogens e iimolekyuli zabo kwi-atom carbon zaseprayimari. Umz, CH 3 -CH 2 -CH 2 Br.
Ukuba ngexesha lokudlala of galogenuglevodorododnaya umxube iikhompawundi ezimbini, amafu xo ezintathu ezahlukeneyo kwakhiwa imveliso. Umzekelo indlela abasabela ngayo ayanceda sodium alkane intsebenziswano kunye chloromethanes kunye hloretanom. Le mveliso ngumxube equka butane, propane ne-methane.
Ngaphandle sodium, kunokwenzeka ukuba ukusebenzisa ezinye iintsimbi kwealkali, eziquka lithium okanye potassium.
inkqubo sulfochlorination
Kwakhona ngokuba UReed basabela. Lisebenza umgaqo lokutshintshwa free. Olu hlobo yokusabela ngokuqhelekileyo alkanes ukuba isenzo ngomxube kwe-sulphur dioxide kunye yeKhlorini eziphilayo phambi yelanga.
Le nkqubo iqala kunye nokuqaliswa kwendlela zokusebenza, apho iklorin ingafumaneka radicals ezimbini. Enye alkane ukuhlasela enika eyakhokelela ekubeni kwenziwe amasuntswana alkyl kunye molecule hydrogen chloride. Ngu hydrocarbon ezinkulu eziqhotyoshelwe ukwenza sulphur dioxide amasuntswana ezintsonkothileyo. Ukuzinzisa capture kwenzeka enye yeKhlorini atom kwenye molecule. Le nkcazelo yokugqibela yi sulfonyl chloride alkane, lisetyenziswa kwi Yindibanisela iikhompawundi kumphezulu-esebenzayo.
Ngokwalo, inkqubo sijongeka njengoku:
CLCL → hv ∙ Cl + ∙ Cl,
HR + ∙ Cl → R ∙ + HCl,
R ∙ + Oso → ∙ ber 2,
∙ ber 2 + ClCl → ber 2 Cl + ∙ Cl.
Iinkqubo ezinxulumene ne nitration
Alkanes azithethelele nitric acid kumxube-10% kunye tetravalent nitrogen oxide ukwimeko sukube. Imiqathango livela yindlela amaxabiso aphezulu lobushushu (malunga 140 ° C) kunye nemilinganiselo uxinzelelo eliphantsi. Xa imveliso wavelisa nitroalkanes.
Inkqubo free-olukhulu uhlobo ogama emva Isazinzulu konovalov, wavula nitration kuyondelelaniswe: CH 4 + HNO 3 → CH 3 NO 2 + H 2 O.
Le indlela cleavage
Kuba dehydrogenation eqhelekileyo alkane nokuqhekeka. IMethane molecule ivavanywa a yokubola epheleleyo thermal.
Indlela osisiseko iimpendulo ezingasentla cleavage-athom ezivela alkanes.
inkqubo dehydrogenation
Xa olwahlula athom hydrogen phezu carbon amathambo paraffins, ngaphandle methane lufumaneka iikhompawundi ezihluthiyo. ngayo ezinjalo lwemichiza alkanes avavanywa lobushushu eliphezulu (400 ukuya-600 ° C) kwaye phantsi accelerators inyathelo platinum, nickel, oxides chromium aluminium.
Ukuba inxaxheba indlela methane okanye propane molekyuli, ngoko imveliso yayo iza ethene okanye propene omnye bond kabini.
Le dehydrogenation ngamathambo ezine okanye ezintlanu-carbon wafumana diene compound. Ukusuka kwakhiwa butadiene butane-1,3 ze-butadiene 1,2.
Ukuba ikhona kwi indlela izinto kunye athom-6 okanye nangaphezulu carbon, benzene yenziwe. Kuye i ring enuka ngemixokelelwane ezintathu kabini.
Inkqubo ezinxulumene yokubola
Phantsi lobushushu eliphezulu abasabela alkanes nga ndibuweze njengokutyhoboza iibhondi carbon kwaye ukuyilwa kweentlobo akhutheleyo uhlobo olukhulu. iinkqubo ezinjalo zibizwa ngokuba nokuqhekeka okanye pyrolysis.
Amalahle i reactants kumaqondo ngaphezulu 500 ° C, iziphumo yokubola molekyuli apho akhiwa umxube entsonkothileyo alkyl-yohlobo radicals.
Ukufeza phantsi zokufudumeza elinqatyisiweyo pyrolysis of alkanes kunye carbon ikhonkco ubude ngenxa ukufumana iikhompawundi elizele eyaneleyo. Ibizwa nokuqhekeka thermal. Le nkqubo isetyenziswa de kwinkulungwane yama-20.
Le ethile ukuba bafumane hydrocarbon kunye nenombolo octane ephantsi (ngaphantsi kwe 65), ngoko indawo ng kuvala. Le inkqubo ke ithabatha indawo kwiqondo lobushushu ukuba ngezantsi 440 ° C, kunye nengcinezelo umoya ngaphantsi kwe-15, phambi kwe i alkanes namafutha release aluminosilicate ukuba isakhiwo branched. Umzekelo pyrolysis methane: 2Kr 4 → t ° C 2 H 2 + 3h 2. Yabumba hydrogen iasithilini ezinto ngexesha basabela njani.
Le molecule ukuze phantsi ukuguqulwa methane. Kule asabela kufuna amanzi kunye kuvala nickel. Imveliso ngumxube carbon monoxide kunye hydrogen.
iinkqubo igcwala
Le abasabela imichiza ukuba alkane ezithile ezinxulumene nefuthe electron.
Kukho auto-igcwala of paraffins. Oku kubandakanya indlela olukhulu mahala igcwala of hydrocarbon kwizinyibilikisi. Ngexesha reaction, isigaba engamanzi hydroperoxide alkane ifunyenwe. Ekuqaleni molecule iparafini idityaniswe oksijini radicals esebenzayo eyabelwe. Okulandelayo, alkyl yamasuntswana lisebenzisana omnye zinemoletyhule O 2, wafumana ∙ Roo. Ukusukela olukhulu peroxy of a acid okunamafutha adibane molecule alkane, bandula ke bakhululwa hydroperoxide. Umzekelo autooxidation ka-methane:
C 2 H 6 + O 2 → ∙ C 2 H 5 + HOO ∙,
∙ C 5 H 2 + O 2 → ∙ OOC 2 H 5,
∙ OOC 2 H 5 + C 2 H 6 → HOOC 2 H 5 + ∙ C 2 H 5.
Kuba alkane luphawulwa indlela yokutsha ukuba ubukhulu becala iipropati imichiza, xa kujongwa ulwakhiwo isibaso. Bona oxidative indalo kunye ukukhutshwa ubushushu: 2C 2 H 6 + 7O 2 → 4CO 2 + 6H 2 O.
Ukuba le nkqubo ugcinwe imali encinane ioksijini, imveliso isiphelo ingaba divalent carbon okanye carbon monoxide, nto leyo ixhomekeke kwindlela ekwakugquba ngayo O 2.
Xa igcwala of alkanes phantsi kwempembelelo kwezinto zokuphosa kwaye ndinobushushu 200 ° C zifunyenwe yomoya utywala, aldehyde okanye carboxylic acid.
UMZEKELO-methane:
C 2 H 6 + O 2 → C 2 H 5 Azaba (ethanol),
C 2 H 6 + O 2 → CH 3 cho + H 2 Owu (ethanal kunye namanzi)
2C 2 H 6 + 3O 2 → 2Ch 3 COOH + 2H 2 Owu (ethanoic acid kunye namanzi).
Alkanes kungenziwa oxidized phantsi intshukumo ye peroxides elibujikele trinomial. Ezi ziquka dimethyl dioxirane. Isiphumo igcwala of molecule paraffins utywala.
Abameli paraffins musa ukuphendula KMnO 4 okanye potassium permanganate, ngokunjalo namanzi bromine.
isomerization
On alkanes olwenze uhlobo endaweni reaction kunye yindlela electrophilic. Oku kubizwa isomerization chain carbon. Catalyzes le nkqubo chloride aluminiyam, apho baye a iparafini ifumile. Umzekelo isomerization of butane molecule, nto leyo 2-methylpropane: C 4 H 10 → C 3 H 7 CH 3.
inkqubo flavoring
izinto igcwaliswe apho kwikhonkco engundoqo carbon iqulethe athom carbon ezintandathu okanye ngaphezulu, ekwaziyo eqhuba dehydrocyclization. Kuba molekyuli amafutshane nobuntu lo yabo. Isiphumo kusoloko umsesane-membered ezintandathu njengoko cyclohexane nezakhi zayo.
Phambi accelerators reaction, kwaye eyipasile dehydrogenation ngakumbi ukuguquka ibe isangqa benzene womelele ngakumbi. Oku kwenzeka baguqula hydrocarbon acyclic ukuya aromatics okanye enkundleni. Umzekelo dehydrocyclization of hexane:
H 3 C-CH 2 - CH 2 - CH 2 - CH 2 -CH 3 → C 6 H 12 (cyclohexane)
C 6 H 12 → C 6 H 6 + 3h 2 (benzene).
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