Nyob rau hauv cov organic chemistry ib qho tuaj yeem ua tau raws li cov tshuaj hydrocarbon nrog cov pa roj carbon sib txawv hauv cov saw thiab C=C-bond. Lawv yog homologues thiab hu ua alkenes. Vim lawv cov qauv, lawv muaj tshuaj lom neeg ntau dua li alkanes. Tab sis qhov tseeb yog lawv cov kev xav li cas? Xav txog lawv qhov kev faib tawm hauv qhov xwm txheej, ntau txoj hauv kev tau txais thiab thov.
lawv yog dab tsi?
Alkenes, uas tseem hu ua olefins (roj), tau txais lawv lub npe los ntawm ethene chloride, ib tug derivative ntawm thawj tus neeg sawv cev ntawm pab pawg no. Txhua alkenes muaj tsawg kawg yog ib C=C ob daim ntawv cog lus. C H2n - cov mis ntawm tag nrho cov olefins, thiab lub npe yog tsim los ntawm ib tug alkane nrog tib tus naj npawb ntawm carbons nyob rau hauv lub molecule, tsuas yog lub ntsiab lus. -kev hloov pauv rau -ene. Tus lej Arabic ntawm qhov kawg ntawm lub npe los ntawm hyphen qhia cov lej carbon los ntawm ob qhov nyiaj pib. Xav txog lub ntsiab alkenes, lub rooj yuav pab koj nco qab lawv:
| Alkane | Npe | Alkene | Npe |
| C2H6 | ethane | ethene (ethylene) | |
| propane | C3H6 | propene (propylene) | |
| C4H10 | C4H8 | butene-1 | |
| C5H12 | pentane | C5H10 | pentene-1 (amylene) |
| C6H14 | hexane | C6H12 | hexene-1 (hexylene) |
| C7H16 | heptane | C7H14 | heptene-1 (heptylene) |
| C8H18 | octane | C8H16 | octene |
| C9H20 | nonane | C9H18 | none |
Yog hais tias cov molecules muaj ib tug yooj yim unbranched qauv, ces ntxiv cov suffix -ylene, qhov no kuj yog reflected nyob rau hauv lub rooj.
Koj tuaj yeem pom lawv nyob qhov twg?
Vim tias qhov kev ua haujlwm ntawm alkenes siab heev, lawv cov neeg sawv cev hauv qhov xwm txheej tsis tshua muaj. Lub hauv paus ntsiab lus ntawm lub neej ntawm olefin molecule yog "cia peb ua phooj ywg." Tsis muaj lwm yam khoom nyob ib puag ncig - tsis muaj teeb meem, peb yuav ua phooj ywg nrog ib leeg, tsim cov polymers.
Tab sis lawv muaj, thiab cov neeg sawv cev me me suav nrog cov roj av cuam tshuam, thiab cov siab dua yog cov roj tsim hauv Canada.
thawj tus neeg sawv cev ntawm alkenes ethene yogCov tshuaj hormones uas txhawb cov txiv hmab txiv ntoo ripening, yog li nws yog synthesized me me los ntawm cov neeg sawv cev ntawm cov nroj tsuag. Muaj ib qho alkene cis-9-tricosene, uas nyob rau hauv cov poj niam houseflies plays lub luag hauj lwm ntawm kev sib deev attractant. Nws tseem hu ua Muscalur. (Attractant - ib yam khoom ntawm lub hauv paus chiv keeb los yog hluavtaws, uas ua rau attraction mus rau qhov chaw ntawm tsw ntxhiab nyob rau hauv lwm yam kab mob). Los ntawm qhov pom ntawm chemistry, qhov no alkene zoo li no:
Vim tag nrho cov alkenes yog cov khoom siv tseem ceeb heev, txoj hauv kev kom tau txais lawv cov khoom tsim muaj ntau yam. Xav txog qhov feem ntau.
Thiab yog tias koj xav tau ntau?
Hauv kev lag luam, chav kawm ntawm alkenes feem ntau tau los ntawm kev tawg, i.e. splitting ntawm cov molecule nyob rau hauv tus ntawm cov kub kub, siab alkanes. Cov tshuaj tiv thaiv yuav tsum tau cua sov hauv thaj tsam ntawm 400 txog 700 ° C. Cov alkane cais raws li nws xav tau, tsim alkenes, cov txheej txheem uas peb tab tom txiav txim siab, nrog ntau tus qauv molecular xaiv:
C7H16 -> CH3-CH=CH 2 + C4H10.
Lwm txoj hauv kev yog hu ua dehydrogenation, nyob rau hauv uas lub hydrogen molecule raug cais los ntawm tus neeg sawv cev ntawm alkane series nyob rau hauv lub xub ntiag ntawm ib tug catalyst.
Nyob rau hauv lub chaw kuaj mob, alkenes thiab txoj kev tau txais yog txawv, lawv yog raws li kev tshem tawm cov tshuaj tiv thaiv (tshem tawm ntawm ib pawg ntawm atoms tsis hloov lawv). Feem ntau, dej atoms raug tshem tawm ntawm cawv, halogens, hydrogen lossis hydrogen halide. Txoj hauv kev zoo tshaj plaws kom tau txais alkenes yog los ntawm cawv nyob rau hauv lub xub ntiag ntawmacid raws li ib tug catalyst. Lwm cov catalysts yuav raug siv
Txhua qhov kev tawm tsam tawm tsam yog raug rau Zaitsev txoj cai, uas nyeem:
Ib tug hydrogen atom raug cais tawm ntawm cov pa roj carbon uas nyob ib sab mus rau cov pa roj carbon bearing pawg -OH, uas muaj tsawg hydrogens.
Tom qab ua raws li txoj cai, teb cov tshuaj tiv thaiv twg yuav yeej? Tom qab ntawd koj yuav paub yog tias koj teb raug.
tshuaj muaj zog
Alkenes nquag ua haujlwm nrog cov tshuaj, rhuav tshem lawv cov pi-bond (lwm lub npe rau C=C daim ntawv cog lus). Tom qab tag nrho, nws tsis muaj zog li ib leeg (sigma daim ntawv cog lus). Lub unsaturated hydrocarbon hloov mus rau hauv ib qho saturated yam tsis tsim lwm yam tshuaj tom qab cov tshuaj tiv thaiv (ntxiv rau).
Cov hauv qab no yog cov tshuaj tiv thaiv feem ntau ntawm alkenes uas tau ua nyob rau hauv ntau hom kev ua ub no ntawm tib neeg:
- ntxiv hydrogen (hydrogenation). Lub xub ntiag ntawm lub catalyst thiab cua sov yog xav tau rau nws txoj kev;
- txuas ntawm halogen molecules (halogenation). Nws yog ib qho ntawm cov txiaj ntsig zoo rau pi daim ntawv cog lus. Tom qab tag nrho, thaum alkenes hnov mob nrog dej bromine, nws ua pob tshab los ntawm xim av;
- tawm tsam nrog hydrogen halides (hydrohalogenation);
- dej ntxiv (hydration). Cov tshuaj tiv thaiv yog cua sov thiab muaj cov catalyst (acid);
Cov tshuaj tiv thaiv tsis sib xws ntawm olefins nrog hydrogen halides thiab dej ua raws li Markovnikov txoj cai. Qhov no txhais tau hais tias hydrogen yuav koom nrog cov pa roj carbon monoxide los ntawm carbon-carbon ob daim ntawv cog lus, uas twb muaj ntau duahydrogen atoms.
- burning;
- ib nrab oxidation catalytic. Cov khoom yog cyclic oxides;
- isomerization. Txhua hom yog yam ntxwv: cis- thiab trans-, ob daim ntawv cog lus hloov chaw, cyclization, skeletal isomerization;
- polymerization yog cov cuab yeej tseem ceeb ntawm olefins rau kev lag luam.
Y Wagner cov tshuaj tiv thaiv (oxidation nrog permanganate hauv nruab nrab nruab nrab). Cov tshuaj tiv thaiv alkene no yog lwm qhov zoo C=C daim ntawv cog lus. Thaum lub caij cog qoob loo, cov tshuaj ntsuab ntawm poov tshuaj permanganate discolors. Yog tias tib cov tshuaj tiv thaiv tau ua nyob rau hauv ib puag ncig acidic, cov khoom yuav txawv (carboxylic acids, ketones, carbon dioxide);
daim ntawv thov kho mob
Cov khoom siv tshuaj tiv thaiv ntawm alkenes yog qhov tseem ceeb tshaj plaws. Ntau ntawm lawv yog siv rau hauv tshuaj. Glycerin tau txais los ntawm propene. Cov dej cawv polyhydric no yog cov kuab tshuaj zoo heev, thiab yog tias siv los hloov dej, cov kev daws teeb meem yuav muaj ntau dua. Rau kev kho mob, alkaloids, thymol, iodine, bromine, thiab lwm yam yog yaj nyob rau hauv nws, glycerin kuj tseem siv rau hauv kev npaj tshuaj pleev, pastes thiab cream. Nws tiv thaiv lawv los ntawm ziab tawm. Los ntawm nws tus kheej, glycerin yog tshuaj tua kab mob.
Thaum hnov mob nrog hydrogen chloride, derivatives tau txais uas tau siv los ua tshuaj loog hauv zos thaum siv rau ntawm daim tawv nqaij, nrog rau kev siv tshuaj loog luv luv nrog kev phais me me, siv kev nqus pa.
Alkadienes yog alkenes nrog ob daim ntawv cog lus ob zaug hauv ib lub molecule. Lawv daim ntawv thov tseem ceeb- kev tsim cov roj hmab hluavtaws, los ntawm ntau lub tshuab cua sov thiab cov koob txhaj tshuaj, cov tshuaj sojntsuam thiab cov catheters, hnab looj tes, txiv mis thiab ntau ntxiv, uas yog qhov tseem ceeb ntawm kev saib xyuas cov neeg mob.
Industrial applications
| Tim kev lag luam | Yuav siv dab tsi | Yuav siv tau li cas |
| Agriculture | ethene | nrawm nrawm ntawm cov zaub thiab txiv hmab txiv ntoo, defoliation ntawm cov nroj tsuag, zaj duab xis rau tsev cog khoom |
| paj-colourful | kom tau cov kuab tshuaj, ethers, cov kuab tshuaj | |
| Engineering | 2-methylpropene, ethene | hluavtaws roj hmab ntau lawm, lubricating roj, antifreeze |
| khoom noj khoom haus | ethene | tsim Teflon, ethyl cawv, acetic acid |
| tshuaj lom neeg kev lag luam | tau txais cawv, polymers (polyvinyl chloride, polyethylene, polyvinyl acetate, polyisobutylene, acetaldehyde | |
| Mining | ethen et al | explosives |
Alkenes thiab lawv cov derivatives tau pom cov ntawv thov dav hauv kev lag luam. (Qhov twg thiab siv cov alkenes li cas, saib cov lus saum toj no).
Nov yog ib feem me me ntawm kev siv cov alkenes thiab lawv cov derivatives. Txhua xyoo qhov kev xav tau ntawm olefins tsuas yog nce, uas txhais tau hais tias qhov kev xav tau ntawm lawv cov khoom kuj nce ntxiv.
(teb: butene-2.)
