Lipotso tsa Mehlala le Puisano ea Likarabelo tse Ikhethang Lihlopheng tse Sebetsang
K'hemistring ea lintho tse phelang, sehlopha se sebetsang ke sehlopha sa liathomo ka har'a molek'hule se ikarabellang bakeng sa thepa ea eona ea lik'hemik'hale le karabelo ea eona. Kutloisiso e felletseng ea likarabelo tse itseng tse amang lihlopha tse fapaneng tsa ts'ebetso ke senotlolo sa ho tseba tšimo ena. Sengoloa sena se tla akaretsa mehlala e 'maloa le ho buisana ka likarabelo tse itseng tse amang lihlopha tse 'maloa tse tloaelehileng tsa ts'ebetso, ho kenyeletsoa li-alkanes, li-alkenes, li-alkynes, li-alcohols, li-ether, li-aldehydes, li-ketone, li-carboxylic acid, li-ester le li-amine.
1. Likarabelo tsa Phetolo ho Alkanes
Mohlala oa mathata
Karabelo pakeng tsa methane (CH₄) le chlorine (Cl₂) tlas'a tšusumetso ea khanya ea ultraviolet (UV) e hlahisa lihlahisoa tse 'maloa. Ngola karabelo e hlahang 'me u khetholle sehlahisoa se seholo.
Puisano
Ka kakaretso li-alkanes ha li arabele haholo, empa li ka arabela ka liketso tsa ho nkela sebaka tsa li-free radical. Mona, methane e arabela le chlorine ts'ebetsong e tsejoang e le halogenation ea li-free radical, e ka aroloang ka tsela e latelang:
1. Qalo: Ho thehoa ha di-radical tsa chlorine ka ho arohana ha homolytic ka ho monya matla a UV.
\[
Cl_2 \motsu o letona 2Cl^\bulete
\]
2. Ho ata ha tsona: Li-radical tsa chlorine li hlasela limolek'hule tsa methane ho etsa li-radical tsa methyl le hydrochloric acid:
\[
Cl^\bullet + CH_4 \motsu o nepahetseng CH_3^\bullet + HCl
\]
Ka mor'a moo, methyl radical e arabela le molek'hule e 'ngoe ea chlorine ho etsa chloromethane le chlorine radical e ncha:
\[
CH_3^\kulo + Cl_2 \motsu o nepahetseng CH_3Cl + Cl^\kulo
\]
3. Pheliso: Li-radical li kopana le ho theha lihlahisoa tse tsitsitseng:
\[
Cl^\bulete + Cl^\bulete \motsu o nepahetseng Cl_2
\]
\[
CH_3^\kulo + Cl^\kulo \motsu o nepahetseng CH_3Cl
\]
\[
CH_3^\kulo + CH_3^\kulo \motsu o nepahetseng C_2H_6
\]
Sehlahisoa se seholo sa karabelo ena ke chloromethane (CH₃Cl).
2. Likarabelo tsa Tlatsetso ho Alkenes
Mohlala oa mathata
Propylene (C₃H₆) e arabela le bromine (Br₂) tlas'a maemo a seng a polar. Ngola karabelo e hlahang 'me u khetholle sehlahisoa se seholo.
Puisano
Li-alkenes li ka nka karolo liketsong tsa ho eketsa ka motlakase. Tlas'a maemo a seng a polar, karabelo e nang le bromine e kenyelletsa ho thehoa ha ion ea bromonium e le karolo e bohareng:
1. Sebopeho sa li-ion tsa bromonium:
\[
C_3H_6 + Br_2 \motsu o nepahetseng [C_3H_6Br]^+ + Br^-
\]
2. Ion ea bromide e hlasela e 'ngoe ea lik'habone tse amehang ho ion ea bromonium, e hlahisa sehlahisoa sa tlatsetso sa 1,2-dibromoalkane:
\[
[C_3H_6Br]^+ + Br^- \rightarrow C_3H_6Br_2
\]
Sehlahisoa se seholo ke 1,2-dibromopropane (C₃H₆Br₂).
3. Likarabelo tse Eketsehileng tsa Alkynes
Mohlala oa mathata
Ethylene (C₂H₂) e arabela le metsi ha ho na le sulfuric acid e matla le mercury(II) sulfate. Ngola mokhoa oa karabelo le lihlahisoa tsa mantlha.
Puisano
Li-alkyne li arabela le metsi ka ho eketsa hydrolytic ea sulfuric acid le mercury (II) e le catalyst, e hlahisang joala ba vinyl, boo ka mor'a moo bo fetohang ketone (auto-tautomerization). Mehato ke e latelang:
1. Sebopeho sa alkenyl mercury complex:
\[
HC \equiv CH + HgSO_4 \motsu o nepahetseng [HC=CH_2Hg]SO_4
\]
2. Ho eketsa metsi:
\[
[HC=CH_2Hg]SO_4 + H_2O \motsu o nepahetseng [CH_3CH_2OH]SO_4
\]
3. Tautomerization e hlahisa acetaldehyde:
\[
CH_3CHO
\]
Sehlahisoa se seholo sa karabelo ena ke acetaldehyde (CH₃CHO).
4. Likarabelo tsa Oxidation ho Joala
Mohlala oa mathata
Taba ea pele, butanol (1-butanol, CH₃(CH₂)₃OH) e oxidized tlas'a maemo a asiti ka potassium permanganate (KMnO₄). Ngola karabelo e hlahang le sehlahisoa sa ho qetela.
Puisano
1-butanol e tla feta oxidation ho butanal (aldehyde) ebe e fetela ho butanoic acid (carboxylic acid):
1. Ho kenella ha oksijene ho aldehyde (butanal) qalong:
\[
CH₃(CH₂)₂CH₂OH \motsu o letona CH₃(CH₂)₂CHO
\]
2. Ho eketsa ho kena ha oksijene ho asiti ea carboxylic (asiti ea butanoic):
\[
CH₃(CH₂)₂CHO + [O] \motsu o nepahetseng CH₃(CH₂)₂COOH
\]
Sehlahisoa sa ho qetela sa karabelo ena ke butanoic acid (CH₃(CH₂)₂COOH).
5. Karabelo ea Hydrolysis ea Li-Ester
Mohlala oa mathata
Methyl acetate (CH₃COOCH₃) e haelloa ke metsi tlas'a maemo a asiti. Ngola karabelo e hlahang 'me u khetholle sehlahisoa se seholo.
Puisano
Li-Esters li tla feta hydrolysis tlas'a maemo a asiti ho hlahisa li-acid tsa carboxylic le alcohols:
1. Protonation ea li-ester:
\[
CH₃COOCH₃ + H^+ \motsu o nepahetseng [CH₃COOHCH₃]^+
\]
2. Ho eketsa metsi le tahlehelo ea methanol:
\[
[CH₃COOHCH₃]^+ + H_2O \motsu o nepahetseng CH₃COOH + CH₃OH
\]
Lihlahisoa tse ka sehloohong tsa karabelo ena ke acetic acid (CH₃COOH) le methanol (CH₃OH).
6. Likarabelo tsa ho Nkela Sebaka ha Nucleophilic ho Ethers
Mohlala oa mathata
Dimethyl ether (CH₃OCH₃) e arabela le hydroiodic acid (HI) mochesong o phahameng. Ngola karabelo e hlahang le sehlahisoa se seholo.
Puisano
Li-ether li tla feta liketsong tsa ho nkeloa sebaka ke nucleophilic tlas'a tšusumetso ea li-acid tse matla tse kang hydroiodic acid:
1. Protonation ea Ether:
\[
CH₃OCH₃ + HI \motsu [CH₃OHCH₃]^+ke^-
\]
2. Tahlehelo ea iodomethyl le ho thehoa ha methanol:
\[
[CH₃OHCH₃]^+I^- \motsu o nepahetseng CH₃OH + CH₃I
\]
Lihlahisoa tse ka sehloohong tsa karabelo ena ke methanol (CH₃OH) le iodomethane (CH₃I).
Ka kutlwisiso e tiileng ea likarabelo tse itseng tsa lihlopha tse fapaneng tse sebetsang, re ka rala litsela tsa maiketsetso hamolemo, ra bolela esale pele lihlahisoa tsa karabelo, 'me ra utloisisa litšobotsi tsa lik'hemik'hale tsa limolek'hule tse rarahaneng haholoanyane. Likarabelo tse tšohloang mona ke tsa bohlokoa 'me li na le lits'ebeliso tse pharaletseng makaleng a fapaneng a k'hemistri ea tlhaho le k'hemistri ea baeloji.
