Kuzvitsinhanisa kuita: tsananguro, mukana wokuti vanhu vanga mienzaniso

Vazhinji kuzvitsinhanisa zvakaitwa rinovhura nzira kugadzirira siyana yeimwe ane utility kushanda. A rakakura basa makemikari sayenzi uye indasitiri anopiwa electrophilic uye nucleophilic kuzvitsinhanisa. In Organic kwetunhu, azvaiitwa vane uwandu zvinhu zvinofanira kucherechedzwa.

A-siyana kwemakemikari mananara. kuzvitsinhanisa kuita

Chemical kuchinja chokuita kuchinja nyaya, zvinoverengeka zvakasiyana zvinhu. Angava akasiyana zvaitika, chafariz migumisiro; zvimwe pezvakaitwa vari kuenda kupedza, anouya mamwe makemikari zvakanyatsoenzana. Kuchinja nevasori kwakanyorwa kunowanzoguma nokuwedzera kana kuderedza mwero oxidation. Mune kupatsanura kwemakemikari mananara avo nemigumisiro okupedzisira nezvesimba Qualitative uye quantitative kusiyana reactants kubva zvigadzirwa. Izvi zvinhu zvinogona kusiyaniswa 7 mhando nemakemikari, kusanganisira kuzvitsinhanisa, vanoita maererano anorimwa: A-B-C A + C + B. kwainoita zvokurekodhwa boka rose kwemakemikari mananara zvinopa pfungwa yokuti pakati pokutangira zvinhu ndiyo vanonzi "vavashungurudza "PARTICIPLE substituent ari reagent atomu, Ion dzichipfekeka boka. The kuzvitsinhanisa kuita maitire yakazara uye zvinonhuwirira Mahydrocarbon.

kuzvitsinhanisa zvinogona kuitika muchimiro kaviri Exchange: A-B-C + E C + A-B-E. Mumwe subspecies - misha, semuenzaniso, mhangura, simbi kubva mhinduro hwemhangura sulphate: CuSO ₄ + Fe = FeSO ₄ + cú. Sezvo "kurwisa" inoramba anogona kuita maatomu, ions kana dzichipfekeka mapoka

Homolytic kuzvitsinhanisa (kukuru, SR)

Kana mashandiro pakati yakakura atsamwira covalent Erekitironi peya kunoitika siyana zvirimo zvichaparadzwa proportionally richiparadzirwa pakati "zvimedu" yacho Morekuru. Inotungamirwa vakasununguka radicals. Izvi kusagadzikana PARTICIPLE Kudzikamiswa kunoitika somugumisiro tevera siyana. Somuenzaniso, mune pakugadzirira ethane kubva methane kubudisa vakasununguka radicals munyaya kuzvitsinhanisa maitiro: CH ₄ CH ₃ • + • H; CH ₃ • + • CH ₃ → C2H5; H • + • H → H2. Homolytic chisungo cleavage pamusoro uchishandisa mashandiro ose kuzvitsinhanisa runozivisa alkanes, maitiro ari cheni hunhu. The methane H maatomu anogona successively ne kuiisa chlorine. Saizvozvowo kuti sei pamwe bromine, ayodhini asi haakwanisi zvakananga kutsiva rehydrogen alkanes, fluorine ikasakendenga zvakare nesimba navo.

Heterolytic chisungo cleavage nzira

Kana mashandiro ose Ion aibuda kuzvitsinhanisa siyana, maerekitironi vari vanoiswa anoparadzirwa pakati nezvimedu achangobva yakamuka. Nokusungwa hangaiwa maerekitironi kunosvika zvose nzira imwe "zvimedu", kazhinji, kuti kukurukurirana naye, parutivi yakanga zvaizopedza kunaka arambe achirema ari polar Morekuru. By kuzvitsinhanisa Maitiro zvinosanganisira zvakaitwa paumbwe methyl doro CH ₃ OH. In brommetane CH3Br pakakoromoka morekuru heterolytic hunhu, ari kuremedzwa nezvimedu vari yakatsiga. Methyl anowana kupomera akanaka, uye Bromo - kunaka: CH ₃ Br → CH ₃ ^{+ +} Br ^-; NaOH → Na ^{+ +} OH ^-; CH ₃ ^{+ +} OH ^- → CH ₃ OH; Na ^{+ +} Br ^- ↔ NaBr.

Electrophiles uye nucleophiles

Inoramba kuti vashayiwe maerekitironi uye anogona kuzvigamuchira, vanonzi "electrophiles." Ava kabhoni maatomu waakaita sungano halogens mu haloalkanes. Nucleophiles vane yakakwirira Erekitironi arambe achirema, vari "vakaurayiwa" ungatakurwa maerekitironi kuti pave covalent chisungo. The kuzvitsinhanisa Maitiro vapfumi mhosva kunaka zviri vakarwiswa nucleophiles electrophiles, dhefisiti pamusoro maerekitironi. Fani iyi chokuita sangano kwemaatomu kana zvimwe zvacho - kusiya boka. Chimwe siyana kuzvitsinhanisa siyana - wokurwisa electrophile nucleophile. Dzimwe nguva zvakaoma kusiyanisa pakati mbiri dzinotsanagura, akataura yokutsiva mumwe kana mumwe mhando, nekuti zvakaoma tsanangurai chaizvo kworudzii Morekuru - substrate, uye iyo - reagent. Kazhinji kacho zvakadaro, zvinhu zvinotevera vanoonekwa:

• yezvakaita kusiya boka;
• ari reactivity of nucleophile;
• yezvakaita solvent;
• ari alkyl mugove yechivako chacho.

Nucleophilic kuzvitsinhanisa (SN)

In nedanho nekuita muna makemikari Morekuru yave ichiwedzera polarization. Mune equations pakati haasaruri akanaka kana akaipa mutariri zvinoratidzwa tsamba wechiGiriki arufabheti. Polarization kutaurirana anopa kunoratidza hunhu waro atsamwira uye remangwana mufambiro "zvimedu" yacho Morekuru. Somuenzaniso, imwe kabhoni atomu pachinhu iodomethane ane zvakanaka kupomera zvishomanana, chinhu electrophilic pakati. Kunokwezva ari dipole mvura, uko okisijeni ane nekumwisa maerekitironi. In maitiro electrophile ine nucleophile aumbwa methanol: CH ₃ Ini + H ₂ O → CH ₃ OH + HI. nucleophilic kuzvitsinhanisa Maitiro kutora nzvimbo pamwe kutora chikamu Muza isakarurama mhosva kana Morekuru ane vakasununguka Erekitironi hangaiwa chisingazivi kubatanidzwa kusikwa makemikari chisungo. Active kubatanidzwa kuti iodomethane mu SN _2-maitiro nokuda kubudirana pachena rayo nucleophilic kurwisa uye ayodhini mufambo.

Electrophilic kuzvitsinhanisa (SE)

The Organic Morekuru anogona kuvapo nucleophilic pakati, izvo ichazivikanwa noku nekumwisa Erekitironi arambe achirema. It zvaanoita pamwe nokushayikwa kupomera akaipa electrophilic reagent ose. nezvimedu akadaro maatomu kuva akasununguka orbital Morekuru pamwe zvikamu kuderedzwa Erekitironi arambe achirema. The yavaibvisa Formate kabhoni have mutariri "-", iri vakaita uine chikamu mvura dipole - rehydrogen: CH ₃ Na + H ₂ Haiwa → CH ₄ + NaOH. Zvinobikwa ichi kuita, electrophilic kuzvitsinhanisa - methane. Kana heterolytic siyana anosangana oppositely mhosva nzvimbo Organic mamorekuru, izvo zvinovapa nokushamwaridzana ions mu inorganic zvinhu kemisitiri. Hazvifaniri kufuratirwa kuti kutendeuka Organic yeimwe haawanzopiwi pamwe paumbwe cations izvi uye anions.

Unimolecular uye bimolecular siyana

The nucleophilic kuzvitsinhanisa iri monomolecular (SN1). By mashandiro ichi, unokosha chigadzirwa runoyerera hydrolysis kuti makemikari kwetunhu - tertiary butyl chloride. Danho rokutanga anononoka, inobatanidzwa mberi dissociation kupinda carbonium nokuo- nga uye chloride anion. Danho rechipiri iri nokukurumidza maitiro kunoitika carbonium Ion uye mvura. Mukana wokuti vanhu vanga vari kuita kuti kuzvitsinhanisa pakati halogen ari alkane kuwana hydroxy uye chikuru doro: (CH _{3) 3} C-Cl → (CH _{3) 3} C ^{+ +} Cl ^-; (CH _{3) 3} C ^{+ +} H ₂ O → (CH _{3) 3} C-OH ⁺ H +. Nokuti mumwe-danho hydrolysis pamusoro nesekondari alkyl halides hwokuratidza kuparadzwa mawa pamusoro kabhoni nokuda halogen uye paumbwe vaviri C-OH. Izvi nucleophilic bimolecular kuzvitsinhanisa mashandiro (SN2).

Heterolytic mashandiro kuti kuzvitsinhanisa

kuzvitsinhanisa mashandiro kunosanganisira Erekitironi kutapurirana, pakusika zvenguva zvivako. The kuita anobuda zvakawanda nokukurumidza, zvinova nyore kuti chaiwo intermediates wake. Kazhinji izvi chinoenda akawanda mirayiridzo panguva imwe chete. Kunakisa anowanzonakidzwa nzira iyo inoramba inoshandiswa, yaida muduku simba rakawanda kune inotungamirwa. Somuenzaniso, kuvapo miviri chisungo kunowedzera mukana wokuti munhu allyl nokuo- nga CH 2 = CH-CH ₂ ^+, zvichienzaniswa kune _CH3 ⁺ Ion. Chikonzero iri Erekitironi arambe achirema ari vakawanda chisungo, izvo kunokanganisa delocalization zvakanaka vebasa, vakapararira pamusoro yose Morekuru.

benzene kuzvitsinhanisa kuita

The boka kuti makemikari yeimwe, ayo kuburikidza electrophilic kuzvitsinhanisa inozivikanwa - nhandare. Benzene mhete - mukana chinhu nokuda electrophilic kurwisa. The kwacho kunotanga kutaura rechipiri polarization reagent, nokudaro achiumba electrophile Erekitironi gore pedyo ari benzene mhete. Zvinoguma kunzwisisa kuchinja. Zvinokosha kutaurirana electrophilic nezvimedu nomumwe kabhoni maatomu kuchigere, zviri mwoyo yose kunaka mutariri "anonhuhwirira nhanhatu" maerekitironi. In danho nedanho electrophile uye mumwe mhete kabhoni atomu wechitatu anosunga nevakawanda vachipiwa maerekitironi (covalent chisungo). Asi iyi, ndiko kuparadzwa "anonhuhwirira nhanhatu", chiri disadvantageous panyaya yekuwana mudanga inogona kuenderera simba mamiriro. Pane kutanga kuti anogona kunzi "kusunungurwa hwepurotoni." Zvinonzi akatsemura kure H ^+, nokupora hwega kukurukurirana gadziriro, zvemo arenes. Side fuma unotora rehydrogen nokuo- nga ane benzene mhete uye anion kubva rechipiri reagent.

Mienzaniso kuzvitsinhanisa zvinoitwa makemikari kemisitiri

For alkanes kunyanya chairwo kuzvitsinhanisa kuita. Mienzaniso electrophilic uye nucleophilic siyana zvinogona kutungamirira cycloalkanes uye arenes. Similar siyana ari mamorekuru ose Organic zvinhu zviri pasi kwomuzvarirwo ezvinhu, asi kazhinji - uye kudziyisa pamberi catalysts. By zvakafanana uye tsime vakadzidza pezvakaitwa zvinosanganisira electrophilic inonhuwirira kuzvitsinhanisa. Anokosha maitiro iyi mhando:

1. Nitration kuti benzene pamwe nitric asidhi pamberi H ₂ SO ₄ - kunotevera anorimwa: C ₆ H ₆ → C ₆ H ₅ -Kwete _2.
2. The CATALYTIC halogenation pamusoro benzene, kunyanya chlorination, kubudikidza mukana wokuti vanhu vanga: C ₆ H ₆ + Cl ₂ → C ₆ H ₅ Cl + HCl.
3. Inonhuwirira sulfonation kuti benzene unobuda ne "fuming" sulfuric acid, benzenesulfonic asidhi vari aumba.
4. Alkylation - yaitsiva hydrogen atomu kubva benzene mhete kuti alkyl.
5. Acylation - paumbwe ketones.
6. Formylation - kutsiva rehydrogen riri boka Cho uye paumbwe aldehydes.

By kuzvitsinhanisa Maitiro zvinosanganisira nezvinoita alkanes uye cycloalkanes, sezvamakaropafadzwa halogens arwise anowanika C-H chisungo. Derivatization anogona chokuita yaitsiva rimwe, vaviri kana vose hydrogen maatomu ari zvine Mahydrocarbon uye cycloparaffins. Vakawanda galogenoalkanov yakaderera samolecular uremu zvinoshandiswa pakugadzira zvikuru kunzwisisa zvinhu kuva makirasi siyana. Kubudirira kubudirira kudzidza nzira ose kuzvitsinhanisa siyana, akapa simba zvakasimbisa kukura Syntheses pamusana alkanes, cyclo-chikuva uye halogenated Mahydrocarbon.