Zochita M'MALO: kufotokoza, aone kuti pali zitsanzo

Ambiri M'MALO anachita umatsegula njira yokonza mankhwala osiyanasiyana ndi ntchito zofunikira. A mbali yaikulu mankhwala sayansi ndi makampani wapatsidwa electrophilic ndi nucleophilic M'MALO. Mu kaphatikizidwe organic, njira izi ndi zinthu zingapo zochititsa kuti tisaiwale.

A zosiyanasiyana zochitika mankhwala. M'MALO anachita

Chemical kusintha kugwirizana ndi kusintha kwa nkhaniyi, ndi chiwerengero cha zinthu zosiyanasiyana. Mwina zakambidwa osiyana, zotsatira matenthedwe; ena njira akupita kutsiriza, iyo ibwera mu zina mankhwala mgwirizano. Wokonzedwanso mwamakono wothandizila nthawi zambiri limodzi ndi kuwonjezeka kapena kucheperachepera kuchuluka kwa makutidwe ndi okosijeni. Mu gulu la zochitika mankhwala zotsatira komaliza Atchule kusiyana Mkhalidwe ndi kachulukidwe pakati pa reactants kuchokera mankhwala. mbali zimenezi zingakhale wolemekezeka 7 mitundu ya zochita mankhwala, kuphatikizapo M'MALO, oyenda monga mwa chiwembu: A-B-C A + C + B. The kujambula chidule cha gulu lonse la zochitika mankhwala amapereka lingaliro mwa zipangizo poyambira ndi otchedwa "tizilomboto "tinthu substituent mu reagent atomu, ion zinchito gulu. M'malo anachita ndi khalidwe la zimalimbikitsa ndi chimasanduka onunkhira.

M'MALO anachita angayambe mawonekedwe a iwiri kuwombola: A-B-C + E C + A-B-E. Mmodzi subspecies - kusamutsidwa, mwachitsanzo, yamkuwa, yachitsulo ku njira ya sulphate mkuwa: CuSO ₄ + Fe = FeSO ₄ + Cu. Monga "pomenyana" particles akhoza kuchita maatomu, ayoni kapena magulu zinchito

Homolytic M'MALO (amakani, SR)

Pamene limagwirira wa kwakukulu awiri chotupa covalent elekitironi Sizachilendo zinthu zosiyana zidzayenera kukhala mofanana anagawira pakati pa "makombo" a molekyulu ndi. Mapangidwe ankafuna kusintha zinthu mopitirira ufulu. Izi wosakhazikika tinthu olimba kumene kumachitika chifukwa cha zochita wotsatira. Mwachitsanzo, pokonza ethane ku dziko kubala ufulu ankafuna kusintha zinthu mopitirira nawo M'MALO anachita: CH ₄ CH ₃ • + • H; CH ₃ • + • CH ₃ → C2H5; H • + • H → H2. Homolytic chomangira pogawanikana pamawere pa limagwirira opaleshoni ya M'MALO ndi khalidwe la alkanes, anachita ndi khalidwe unyolo. The dziko H maatomu akhoza successively m'malo ndi chlorine. Mofananamo kuchita ndi bromine, ayodini koma siitha mwachindunji m'malo alkanes wa hydrogen, fluorine wakwiya kwambiri mwamphamvu ndi iwo.

Heterolytic chomangira pogawanikana pamawere njira

Pamene limagwirira cha zochita ion otaya M'MALO, ma elekitironi ali omangidwa anagawira mwa particles kumene chikanachitika. Awiri ankameteramo ubweya wa ma elekitironi chimafikira njira yonse mmodzi wa "makombo", nthawi zambiri, kuti kulankhulana naye, mbali yomwe anali kuchepetsa kachulukidwe sizabwino molekyulu kumalo ozizira. Ndi M'MALO zosiyanasiyana monga mmene mapangidwe methyl mowa CH ₃ HA. Mu brommetane CH3Br kusiyana molekyulu ndi khalidwe heterolytic, particles mlandu ndi khola. Methyl amapeza mlandu zabwino, ndi bromo - zoipa: CH ₃ br → CH ₃ ^{+ +} br ^-; NaOH → Na ^{+ +} HA ^-; CH ₃ ^{+ +} HA ^- → CH ₃ HA; Na ^{+ +} br ^- ↔ NaBr.

Electrophiles ndi nucleophiles

Particles kuti alibe ma elekitironi ndipo mukhoza kuzilandira, amatchedwa "electrophiles." Awa ndi mpweya maatomu angongole ndi halogens mu haloalkanes. Nucleophiles ndi mkulu elekitironi osalimba, iwo ali "amachitidwa" wa peyala ya ma elekitironi kulenga covalent muzikondana. Zimene M'MALO wolemera milandu zoipa amaukiridwa ndi nucleophiles electrophiles, kuchepekedwa kwa ma elekitironi. zodabwitsazi amagwirizana ndi kayendedwe ka maatomu kapena particles ena - kusiya gulu. zosiyanasiyana wina mosiyanasiyana M'MALO - kuukira nucleophile electrophile. Nthawi zina kovuta kusiyanitsa pakati pa njira ziwiri, anatchula m'malo a munthu kapena mtundu wina, chifukwa n'zovuta mwachindunji kwenikweni mtundu wanji wa molekyulu - gawo lapansi, ndi limene - reagent. Kawirikawiri Zikatero, zinthu izi amaonedwa:

• chikhalidwe cha kusiya gulu;
• ndi reactivity wa nucleophile ya;
• chikhalidwe cha zosungunulira ndi;
• ndi alkyl gawo la dongosolo la.

Nucleophilic M'MALO (SN)

Mu ndondomeko ya zimachitika mu molekyulu ndi organic wakhala kuwonjezeka kugawanika. Mu maikwezhoni wa tsankho mlandu zabwino kapena zoipa akusonyeza lemba la zilembo za Chigiriki. Kugawanika kulankhulana apereka umboni wa chikhalidwe cha chotupa ake ndi khalidwe tsogolo la "makombo" a molekyulu ndi. Mwachitsanzo, mpweya atomu mu iodomethane ali ndi tsankho mlandu zabwino, ndi malo electrophilic. Chimakopa a dipole wa madzi, kumene mpweya ali owonjezera ma elekitironi. Mu zochita za electrophile ndi nucleophile ndi aumbike methanol: CH ₃ Ine + H ₂ O → CH ₃ HA + moni. nucleophilic M'MALO zochita zichitike nawo ndi ion zoipa mlandu kapena molekyulu ndi ufulu awiri elekitironi, omwe sakhala nawo chilengedwe cha mankhwala muzikondana. Yogwira nawo iodomethane mu SN _2-anachita chifukwa omasukirana ake ndi kuukira nucleophilic ndi ayodini kuyenda.

Electrophilic M'MALO (SE)

Molekyulu organic akhoza kupezeka nucleophilic pakati, amene amakhala ndi owonjezera elekitironi osalimba. Umakaphatikizana ndi kupanda milandu zoipa electrophilic reagent. particles amenewa ndi maatomu omwe ali ndi ufulu yozungulira molekyulu ndi mbali ya wotsikirapo elekitironi osalimba. The ndi sodium formate mpweya ndi mlandu "-", ndi anachitira ndi mbali zabwino mwa dipole madzi - haidrojeni: CH ₃ Na + H ₂ O → CH ₄ + NaOH. The mankhwala a linachepa, electrophilic M'MALO - dziko. Pamene zochita heterolytic kucheza oppositely mlandu malo mamolekyulu organic, amene amawapatsa kuyandikana ndi ayoni mu zinthu zochita kupanga zimapangidwira. Sitiyenera kuiŵala kuti kutembenuka kwa mankhwala organic sikawirikawiri limodzi ndi mapangidwe cations awa ndi anions.

Unimolecular ndi zochita bimolecular

M'malo nucleophilic ndi monomolecular (SN1). Mwa njira imeneyi, chinthu chofunika umayenda hydrolysis wa kaphatikizidwe organic - ukachenjede butyl mankhwala enaake. Gawo loyamba ndi pang'onopang'ono, izo amagwirizana ndi kupata dissociation mu carbonium cation ndi mankhwala enaake anion. Gawo lachiwiri ndi msanga anachita amapezeka carbonium ion ndi madzi. The aone kuti pali zimene a m'malo halogen mu alkane kupeza hydroxy ndi zapulaimale mowa: (CH _{3) 3} C-CL → (CH _{3) 3} C ^{+ +} cl ^-; (CH _{3) 3} C ^{+ +} H ₂ O → (CH _{3) 3} C-HA ⁺ H +. Pakuti sitepe imodzi hydrolysis wa pulayimale ndi sekondale halides alkyl yodziwika ndi chiwonongeko munthawi yomweyo mpweya chifukwa halogen ndi mapangidwe awiri C-HA. Izi nucleophilic bimolecular M'MALO limagwirira (SN2).

Heterolytic limagwirira wa M'MALO

M'MALO limagwirira ikukhudza elekitironi kutengerapo, chilengedwe cha maofesi wapakatikati. Zimene atuluka mofulumira, kosavuta ndi intermediates mmene iye. Nthawi zambiri ndondomeko ukupita mbali zingapo nthawi imodzi. Ubwino kawirikawiri amatenga mmene particles ntchito, amafuna ndalama zosachepera mphamvu kwa mapangidwe ake. Mwachitsanzo, kukhalapo kwa ubwenzi awiri kumachititsa ya Fungo cation CH 2 = CH-CH ₂ ^{+ poyelekeza} ndi _CH3 ⁺ ion. chifukwa lagona pa osalimba elekitironi la mgwirizano angapo, izi zimakhudza delocalization wa mtengo zabwino, omwazika pa molekyulu lonse.

benzene M'MALO anachita

Gulu la mankhwala organic, amene yodziwika ndi M'MALO electrophilic - m'bwalomo. Benzene mphete - chinthu yabwino kuukira electrophilic. ndondomeko akuyamba kulankhula ndi wachiwiri kugawanika reagent, potero kupanga electrophile elekitironi mtambo moyandikana ndi benzene mphete. Chifukwa ndi kusintha zovuta. Wapatali kulankhulana electrophilic particles ndi imodzi mwa ma atomu mpweya ayi komabe, zonse izo umalakalaka lonse mlandu zoipa "onunkhira isanu" ma elekitironi. Mu njira yachitatu ya ndondomeko electrophile ndi chimodzi mphete mpweya atomu chimamanga awiri wamba ma elekitironi (covalent chomangira). Koma mu nkhani iyi, ndi chiwonongeko cha "onunkhira isanu" imene ili disadvantageous mawu a kukwaniritsa khola zisathe boma mphamvu. Pali chinthu chimene chingakhoze kutchedwa "amasulidwe purotoni a." Iwo unagawanika kuchokera H ^+, akuchira dongosolo khola kulankhulana, arenes lililonse. Mbali mankhwala limapangidwa cation wa hydrogen wa mphete benzene ndi anion ku reagent chachiwiri.

Zitsanzo za zochita M'MALO zimapangidwira organic

Pakuti alkanes makamaka mmene M'MALO anachita. Zitsanzo za zochita electrophilic ndi nucleophilic kungachititse kuti cycloalkanes ndi arenes. Similar zochita mu mamolekyulu zinthu organic ndi m'mikhalidwe wabwinobwino, koma nthawi zambiri - ndi Kutentha mu kukhalapo kwa catalysts. Mwa njira wamba ndi bwino kuphunzira monga electrophilic onunkhira M'MALO. Zofunika kwambiri zimene mtundu uwu:

1. Nitration wa benzene acid nitric pamaso pa H _{2 4} - motere chiwembu: C ₆ H ₆ → C ₆ H ₅ Palibe _2.
2. The othandizira halogenation wa benzene, makamaka chlorination, ndi aone kuti pali kuti: C ₆ H ₆ + CL ₂ → C ₆ H ₅ CL + HCl.
3. Onunkhira sulfonation wa benzene chimaposa ndi "fuming" chidulo cha safuriki, asidi benzenesulfonic anapanga.
4. Alkylation - m'malo a atomu wa hydrogen ku benzene mphete ku alkyl.
5. Acylation - mapangidwe ketones.
6. Formylation - m'malo ndi wa hydrogen pa gulu Cho ndi mapangidwe aldehydes.

Ndi M'MALO zosiyanasiyana monga anachita mu alkanes ndi cycloalkanes, mmene halogens kuukira zilipo C-H muzikondana. Derivatization likhoza kulumikizidwa ndi m'malo a wina, awiri kapena onse maatomu wa hydrogen mu chimasanduka zimalimbikitsa ndi cycloparaffins. Ambiri a galogenoalkanov kulemera otsika maselo ntchito kupanga zinthu zovuta kuzimvetsa za thupi magulu osiyanasiyana. The kupambana chikwaniritsidwa mu kuphunzira njira mosiyanasiyana M'MALO, anapereka kutsogolera wamphamvu chitukuko cha syntheses pamaziko a alkanes, cyclo gawo ndi chimasanduka halogenated.