Ukusabela Okuqondile Kwamaqembu Asebenzayo
Ukusabela kwamakhemikhali kuyinhliziyo yekhemistri, kanti amaqembu asebenzayo ayizingxenye zama-molecule aphakathi nomsebenzi wamakhemikhali. Iqembu ngalinye elisebenzayo linokusabela kwalo kanye nezici zalo, okuvumela izinhlobo ezahlukene zokuguqulwa kwamakhemikhali. Ukuqonda ukusabela okuthile kwamaqembu asebenzayo kuyisihluthulelo sokuphatha nokuklama ama-molecule emikhakheni ehlukahlukene, kusukela kwezemithi kuya kubuchwepheshe bezinto.
Amaqembu Asebenzayo: Incazelo Nokubaluleka
Iqembu elisebenzayo yiqembu lama-athomu ku-molecule elisebenza njengeyunithi ephendulayo futhi linquma izakhiwo zamakhemikhali ze-molecule. Izibonelo ezivamile zamaqembu asebenzayo zifaka i-hydroxyl (-OH), i-carbonyl (C=O), i-carboxyl (-COOH), i-amino (-NH2), kanye ne-ether (-COC). Iqembu ngalinye elisebenzayo linezakhiwo ezithile eziphendulayo ezivumela ukusabela kwamakhemikhali athile ukuthi kwenzeke.
Ukusabela Okuqondile Kwamaqembu Asebenzayo
1. Iqembu le-Hydroxyl (-OH)
Amaqembu e-hydroxyl akhona kuma-alcohols nama-phenols, futhi abonisa ukusabela okuhlukahlukene kwamakhemikhali.
Ukusabela kwe-Oxidation
Ama-alcohol angafakwa i-oxid ukuze akhiqize ama-aldehyde, ama-ketone, nama-carboxylic acid. I-oxidation eyinhloko yama-alcohol ikhiqiza ama-aldehyde, abese efakwa i-oxid kuma-carboxylic acid. Ama-alcohol esibili afakwa i-oxid kuma-ketone.
``
R-CH2OH + [O] → R-CHO + [O] → R-COOH
R-CHOH-R' + [O] → R-CO-R'
``
Ukusabela Kokuphelelwa Amanzi
Ukuphelelwa amanzi emzimbeni kwama-alcohol kungakhiqiza ama-alkenes nama-ether. Uma kukhona i-asidi enamandla njenge-H2SO4, ama-alcohol aphelelwa amanzi emzimbeni ngaphakathi kwama-molecule abe ama-alkenes noma aphelelwe amanzi emzimbeni phakathi kwama-molecule abe ama-ether.
``
R-CH2-CH2OH → R-CH=CH2 + H2O (ukuphelelwa amanzi emzimbeni ngaphakathi kwama-molecule)
2 R-OH → ROR + H2O (ukuphelelwa amanzi emzimbeni phakathi kwama-molecule)
``
2. Iqembu le-Carbonyl (C=O)
Amaqembu e-Carbonyl atholakala kuma-aldehydes, ama-ketone, kanye nama-carboxylic compounds. Ukusabela kwawo kufaka phakathi ukwengeza, ukunciphisa, kanye nokujiya kwe-nucleophilic.
Ukwengezwa kwe-Nucleophilic
Ikhabhoni eqenjini le-carbonyl ifana ne-electrophilic futhi ingahlaselwa yi-nucleophile ukuze ikhiqize utshwala.
``
R-CO-R' + NuH → RC(OH)(Nu)-R'
``
Ukusabela Kokunciphisa
Ama-aldehydes nama-ketone angancishiswa abe yi-alcohols ngokusebenzisa ama-reducing agents afana ne-NaBH4 noma i-LiAlH4.
``
R-CHO + 2[H] → R-CH2OH
R-CO-R' + 2[H] → R-CHOH-R'
``
Ukusabela Kokuvunda kwe-Aldol
Ukujiya kwe-Aldol kuhilela ama-molecule amabili e-aldehyde noma e-ketone akhiqiza i-β-hydroxy aldehyde noma i-ketone futhi angaphelelwa amanzi emzimbeni ukuze akhiqize i-enone.
``
2 R-CHO → R-CH(OH)-CH(R)-CHO
R-CHOH-CH(R)-CHO → R-CH=CH(R)-CHO + H2O
``
3. Iqembu le-Carboxyl (-COOH)
Ama-asidi e-carboxylic abonisa ukusabela okufana nokususa i-protonation, i-esterification, kanye nokunciphisa.
Ukusabela Kokuncishiswa Kweprotonation
Ama-asidi e-carboxylic (R-COOH) angalahlekelwa ama-proton ukuze akhe ama-carboxylates (R-COO⁻).
``
R-COOH → R-COO⁻ + H⁺
``
Ukusabela kwe-Esterification
Ama-asidi e-carboxylic asabela nama-alcohol ukuze akhiqize ama-ester namanzi ku-Fischer esterification reaction.
``
R-COOH + R'OH → R-COO-R' + H2O
``
Ukusabela Kokunciphisa
Ama-asidi e-carboxylic angancishiswa abe yi-alcohols kusetshenziswa ama-ejenti okunciphisa anamandla njenge-LiAlH4.
``
R-COOH + 4[H] → R-CH2OH + H2O
``
4. Iqembu lama-Amino (-NH2)
Amaqembu ama-amino akhona kuma-amine futhi abonisa ukusabela kwe-alkylation, acylation, kanye ne-nitrosation.
Ukusabela kwe-Alkylation kanye ne-Acylation
Ama-amine akhiwa yi-alkylation yama-alkyl halides ne-ammonia noma ama-amine. Ama-amine angasabela futhi nama-acyl halides noma ama-anhydride ukuze akhiqize ama-amides.
``
I-RX + NH3 → R-NH2 + HX
R-NH2 + R'-COCl → R-NH-CO-R' + HCl
``
Ukusabela kwe-Nitrosation
Ama-amine ayinhloko nawesibili angabhekana nokusabela kwe-nitrosation ne-nitrous acid ukukhiqiza usawoti we-diazonium wama-amine ayinhloko noma ama-amine e-N-nitrose kuma-amine asibili.
``
R-NH2 + HONO → R-N2⁺ + H2O (usawoti we-diazonium)
R2NH + HONO → R2N-N=O + H2O (N-nitroso amine)
``
5. Iqembu le-Ether (i-COC)
Ama-ether asabela ngendlela ehlukile kune-alcohols ngoba awanawo ama-proton angakhishwa kalula.
Ukusabela Kokuqhekeka Kwe-Acid
Ama-ether angahlukaniswa ngama-asidi aqinile ukuze kukhiqizwe ama-alcohol nama-alkyl halides.
``
RO-R' + HBr → R-OH + R'-Br
``
Ukusabela kwe-Air Autooxide
Ama-ether angangcoliswa umoya ukuze akhiqize ama-ether peroxide aqhumayo.
``
2 RO-R' + O2 → 2 RO-R'-O-OH
``
Isiphetho
Ukuqonda kahle ukusabela okuthile kwamaqembu asebenzayo kumakhemikhali ezinto eziphilayo kubalulekile ezinhlobonhlobo zezicelo ezisebenzayo. Amaqembu asebenzayo anquma izakhiwo zamakhemikhali kanye nokusebenza kabusha kwama-molecule, okwenza kube nokuguqulwa okuhlukahlukene kwamakhemikhali abalulekile kumakhemikhali ezinto eziphilayo, eziphilayo, kanye nezinto zokwakha. Ngokusebenzisa lolu lwazi, osokhemisi bangaklama futhi bakhe ama-molecule amasha anezinhlelo zokusebenza ezibanzi kwezempilo, ubuchwepheshe, nokuningi.
