Nitration ntawm toluene: Cov tshuaj tiv thaiv kab zauv

Wb tham txog yuav ua li cas lub nitration ntawm toluene. Npaj nurses los ntawm reacting ib tug lossis loj tus naj npawb ntawm semifinished khoom siv nyob rau hauv qhov siv thiab ua explosives, pharmaceuticals.

Qhov tseem ceeb ntawm nitration

Benzene derivatives li uas muaj ntxhiab nitro tebchaw yog muaj nyob rau hauv cov niaj hnub tshuaj ua lag luam. Nitrobenzene nyob rau hauv aniline yog ib nrab khoom, naj hoom, kws ntau lawm. Nws yog ib qho zoo heev kuab rau ntau organic tebchaw, xws li cellulose thiab nitrite tsim tau ib gelatinous loj nrog nws. Nyob rau hauv lub roj av lag luam nws yog siv raws li ib tug purifier rau lubricating roj. Thaum lub nitration ntawm toluene yog npaj benzidine, aniline, aminosalicylic acid, phenylenediamine.

Cov yam ntxwv ntawm nitration

Nitration yus inlet NO2 pab pawg neeg mus rau hauv lub molecule ntawm cov organic compound. Nyob rau hauv lub pib khoom, tus txheej txheem no hais ntawm ib tug tshaj dhau, nucleophilic, electrophilic mechanism. Lub active hais ua raws li nitronium cations, ions thiab radicals NO2. Toluene nitration cov tshuaj tiv thaiv hais txog cov kev hloov. Rau lwm yam organic tshuaj tej zaum yuav hloov nitration, thiab qhov sib ntxiv ntawm ob daim ntawv cog lus.

Nitration ntawm toluene nyob rau hauv ib tug qauv ntawm cov uas muaj ntxhiab hydrocarbon yog nqa tawm siv nitrating acid (sulfuric thiab nitric acids). Lub catalyst exhibits zog sulfuric acid pab raws li tus txheej txheem txhais tau tias vodotnimayuschego.

txheej txheem kab zauv

Nitration ntawm toluene yuav muab los ntawm ib tug hydrogen atom los ntawm nitro. Yuav ua li cas puas lub tswvyim ntawm kev txheej txheem?

Nyob rau hauv thiaj li yuav piav qhia txog lub nitration ntawm toluene, cov tshuaj tiv thaiv kab zauv yuav muaj tuaj raws li nram no:

ArH + HONO2 + = Ar-NO2 + H2 O

Nws tso cai rau koj yuav tsum tau txiav txim tsuas yog nyob rau hauv lub dav chav kawm ntawm lub sis, tab sis tsis qhia tawm tag nrho cov yam ntxwv ntawm tus txheej txheem no. Nyob rau hauv qhov tseeb muaj yog ib tug tshuaj tiv thaiv ntawm lub uas muaj ntxhiab hydrocarbons thiab cov khoom ntawm nitric acid.

Muab hais tias cov khoom muaj ib tug dej molecule, nws thiaj li concentration ntawm nitric acid, nitration ntawm toluene yog li ntawd slows. Nyob rau hauv kev txiav txim kom tsis txhob muaj qhov teeb meem no, cov txheej txheem yog nqa tawm thaum uas tsis muaj kub uas siv cov nitric acid nyob rau hauv ib tug dhau heev npaum li cas.

Tsis tas li ntawd ntawm sulfuric acid li dehydrating cov neeg ua hauj siv , acetic anhydride, polyphosphoric acid, boron trifluoride. Lawv pab kom snizat tau ntawm nitric acid, ua rau kom lub efficiency ntawm kev sis raug zoo.

Lub nuances ntawm tus txheej txheem

Lub nitration ntawm toluene piav nyob rau hauv lub lig thib kaum cuaj xyoo pua V. Markovnikov. Nws muaj peev xwm tsim kom muaj ib qhov txuas ntawm hauv lub xub ntiag nyob rau hauv cov tshuaj tiv thaiv sib tov concentrated sulfuric acid thiab cov txheej txheem tus nqi ndlwg. Nyob rau hauv niaj hnub ntau lawm nitrotoluene anhydrous nitric acid yog siv, noj nyob rau hauv me ntsis ntau heev.

Ntxiv mus, sulfonation thiab nitration ntawm toluene yuav siv muaj nyob dehydrating boron fluoride tivthaiv. Nws qhia mus rau hauv cov tshuaj tiv thaiv kev ua kom mus txo tus nqi ntawm cov khoom tau, uas ua rau muaj lub nitration ntawm toluene. Kab zauv ntws txheej txheem feem ntau yog raws li nram no:

ArH + HNO3 + BF3 = Ar-NO2 + BF3 · H2 O

Tom qab kawm tiav ntawm cov tshuaj tiv thaiv dej yog tswvcuab, whereby lub monohydrate boron fluoride dihydrate cov ntaub ntawv. Nws tau raug tshem tawm nyob rau hauv vacuo, ces ntxiv calcium fluoride, rov qab mus rau tus thawj compound daim ntawv.

Tseem ntawm nitration

Muaj ib co nta ntawm tus txheej txheem uas txuam nrog cov kev xaiv ntawm reagents, substrate siv cov tshuaj tiv thaiv. Xav txog ib co ntawm lawv ntau txoj kev xaiv:

• 60-65 feem pua nitric acid nyob rau hauv ib tug sib tov ntawm 96 feem pua sulfuric acid;
• sib tov ntawm 98% nitric acid thiab concentrated sulfuric acid rau cov tshuaj tiv thaiv me ntsis organic tshuaj;
• poov tshuaj nitrate los yog ammonium nrog concentrated sulfuric acid - yog ib qho kev yoj rau zus tau tej cov polymer ntawm nitro tebchaw.

Lub kinetics ntawm nitration

Aromatic hydrocarbons, interacting nrog ib tug sib tov ntawm sulfuric thiab nitric acids, nitro ionically. V. Markovnikov tau tuab lub tseem ntawm tus sis. Cov txheej txheem yuav siv sij hawm qhov chaw nyob rau hauv ob peb ua sawv. Nitrosernaya acid yog thawj tsim, uas undergoes dissociation nyob rau hauv aqueous tov. Nitronium ions yog reacted nrog toluene tsim raws li ib tug khoom nitrotoluene. Thaum ntxiv rau ib tug sib tov ntawm dej lwg me me tshwm sim thaum lub sij hawm deceleration.

Nyob rau hauv cov kuab tshuaj nrog organic xwm - nitromethane, acetonitrile, sulfolane - tso cai rau lub tsim ntawm lub ntawv kom tus nqi ntawm nitration.

Cov uas ua nitronium ntawv uas txuas mus rau lub uas muaj ntxhiab nucleus ntawm toluene, yog li tsim intermediate. Ntxiv muaj yog ib tug proton kis, ua rau lub tsim nitrotoluene.

Rau ib ntxaws qhia txog ntawm cov txheej txheem uas peb yuav xav txog qhov tsim ntawm ib tug "sigma" thiab "pi" complex. Kev Kawm Ntawv "sigma" ntawm lub complex yog tus nqi-limiting kauj ruam ntawm tus sis. Cov tshuaj tiv thaiv tus nqi yog ncaj qha mus txog rau lub rapidity ntawm nitronium ntawv Symptoms rau cov pa roj carbon atom nyob rau hauv lub nucleus ntawm uas muaj ntxhiab tebchaw. proton splitting off of toluene yog nqa tawm yuav luag instantly.

Tsuas yog nyob rau hauv tej lub sijhawm, tej zaum yuav muaj ib co teeb meem nrog rau cov kev hloov uas txuam nrog ib tug tseem ceeb thawj kinetic isotope nyhuv. Qhov no yog vim lub acceleration ntawm qhov rov qab txheej txheem nyob rau hauv lub xub ntiag ntawm obstacles ntawm ntau hom.

Thaum xaiv ib tug catalyst thiab ib tug dehydrating neeg sawv cev nrog concentrated sulfuric acid txheej txheem muaj equilibrium ua haujlwm ntawm lub tsim ntawm cov tshuaj tiv thaiv cov khoom.

xaus

Nws tsim nyob rau hauv lub nitration ntawm toluene nitrotoluene, uas yog ib tug tseem ceeb khoom ntawm cov tshuaj ua lag luam. Nws yog ib qhov tshuaj yog ib tug heev compound, yog li thov nyob rau hauv blasting hauj lwm. Ntawm cov ib puag ncig teeb meem txuam nrog nws cov muaj siv thiab ua, nco ntsoov siv ib tug ntau yam pauv loj npaum li cas ntawm concentrated sulfuric acid.

Yuav kom tiv nrog qhov teeb meem no, chemists tab tom nrhiav rau txoj kev txo pov tseg sulfuric acid tau tom qab lub nitration txheej txheem. Piv txwv li, cov txheej txheem yog nqa tawm ntawm qis kub, qhov nruab nrab siv yog yooj yim regenerable. Sulfuric acid no muaj muaj zog oxidizing zog, uas tsis zoo muaj feem xyuam rau cov xeb hlau yog nce txaus ntshai rau muaj sia nyob. Nyob rau hauv kev ua raws cai nrog tag nrho cov qauv kev ruaj ntseg tau mus rau tiv nrog cov teeb meem no, tau zoo nitro tebchaw.