Dicarboxylic acids yog cov tshuaj uas muaj ob pawg ua haujlwm monovalent carboxyl - COOH, uas nws txoj haujlwm yog los txiav txim siab cov yam ntxwv ntawm cov tshuaj no.
Lawv cov qauv dav dav yog HOOC-R-COOH. Thiab ntawm no, "R" yog hais txog cov organic 2-valent radical, uas yog cov atoms txuas nrog rau pawg ua haujlwm ntawm cov molecule. Txawm li cas los xij, koj tuaj yeem kawm paub ntxiv txog qhov no.
Lub cev muaj zog
Dicarboxylic compounds yog cov khoom. Cov khoom hauv qab no tuaj yeem paub qhov txawv:
- Zoo soluble hauv dej. Nyob rau tib lub sijhawm, hydrogen intermolecular bonds raug tsim.
- The solubility limit in H2O is in the limit C6-C7. Thiab qhov no yog to taub, vim hais tias cov ntsiab lus ntawm carboxyl polar pawg nyob rau hauv lub molecules yog qhov tseem ceeb.
- Tsis zoo soluble hauv cov kuab tshuajorganic keeb kwm.
- Melted ntawm qhov kub ntau dua li cawv thiab chlorides. Qhov no yog vim lub zog siab ntawm lawv cov ntawv cog lus hydrogen.
- Yog cov carboxylic tebchaw raug cua sov, lawv yuav pib decompose nrog kev tso tawm ntau yam tshuaj.
tshuaj muaj zog
Lawv yog tib yam rau carboxylic acids xws li monocarboxylic acids. Vim li cas? Vim lawv kuj muaj pawg carboxyl. Nws, nyob rau hauv lem, muaj ob yam:
- Carbonyl. >C=O. Pab pawg \u003d C \u003d O organic compounds (cov uas suav nrog carbon).
YHydroxyl. -IS HE. OH pawg ntawm cov tebchaw ntawm cov organic thiab inorganic hom. Kev sib txuas ntawm oxygen thiab hydrogen atoms yog covalent.
Carbonyl thiab hydroxyl muaj kev cuam tshuam kev sib raug zoo. Yuav ua li cas raws nraim txiav txim lub acidic zog ntawm cov tebchaw nyob rau hauv kev txiav txim? Qhov tseeb tias polarization ntawm O-H daim ntawv cog lus ua rau muaj kev hloov pauv hauv electron ceev rau carbonyl oxygen.
Nws tsim nyog sau cia tias hauv cov tshuaj aqueous, cov tshuaj ntawm pawg carboxyl dissociate (decompose) rau hauv ions. Nws zoo li no: R-COOH=R-COO- + H+. Los ntawm txoj kev, cov ntsiab lus kub kub ntawm cov kua qaub thiab lawv lub peev xwm yaj hauv dej yog vim qhov tsim ntawm hydrogen intermolecular bonds.
Dissociation
Qhov no yog ib qho ntawm cov khoom ntawm dicarboxylic acids, uas tshwm sim nws tus kheej nyob rau hauv decomposition ntawm ib yam khoom rau hauv ions thaum dissolution. tshwm sim hauv ob theem:
- NOOS-X-COOH → NOOS-X-COO-+N+. Rau thawj theemdicarboxylic acids muaj zog dua monocarboxylic acids. Qhov laj thawj 1 yog ib qho kev txheeb cais. Muaj 2 pawg carboxyl hauv cov molecule. Yog vim li cas 2 - lawv kev sib nrig sib cuam tshuam. Qhov no tshwm sim nyob rau hauv feem ntau, txij li cov pab pawg yog ib qho kev sib txuas los ntawm cov saw hlau ntawm ntau daim ntawv cog lus, lossis tsis nyob deb.
- HOOS-X-SOO- → -OOS-X-SOO -+N+. Tab sis nyob rau theem thib ob, cov kua qaub ntawm pab pawg no ua rau tsis muaj zog dua li cov monocarboxylic. Tsuas yog kab tias rau ethandioic (oxalic). Lub hydrogen cation yog qhov nyuaj rau kev sib cais. Qhov no yuav tsum muaj zog ntxiv. H+ nyuaj dua los cais tawm ntawm anion nrog -2 nqi dua li ntawm -1.
Kev sib cais ntawm dicarboxylic acids tshwm sim tsuas yog hauv cov tshuaj aqueous, txawm hais tias nyob rau lwm qhov xwm txheej cov txheej txheem tshuaj no kuj ua tau thaum lub sijhawm yaj.
Lwm cov tshuaj tiv thaiv
Cov tebchaw uas xav tau tuaj yeem tsim cov ntsev. Thiab tsis zoo tib yam, zoo li monocarboxylic, tab sis qaub. Lawv yog cov yam ntxwv ntawm lub xub ntiag nyob rau hauv muaj pes tsawg leeg ntawm ob hom cations - hlau (nyob rau hauv ib co kev xav, es tsis txhob ntawm lawv, ammonium ions) thiab hydrogen. Lawv kuj muaj ntau tus nqi anion ntawm acid residue - atom uas tsis zoo.
Lub npe ntawm cov ntsev no yog vim qhov tseeb tias thaum lub sij hawm hydrolysis lawv muab cov kua qaub ntawm qhov nruab nrab. Nws yuav tsum tau muab sau tseg tias cov compounds dissociate mus rau ib tug residue nrog ib tug hydrogen particle thiab hlau ions.
Tsis tas li, cov khoom siv tshuaj ntawm dicarboxylic acids txiav txim siab lawv lub peev xwm los tsim cov kua qaub halides. Nyob rau hauv cov tebchaw no, pawg hydroxyl yog hloov los ntawm ib tug halogen, ib tug vigorous oxidizing agent.
Ntse
Nws yog tsis yooj yim sua kom tsis txhob ua ib tug reservation uas tsim ntawm chelates kuj belongs rau cov khoom ntawm dicarboxylic acids. Cov no yog cov sib xyaw ua ke uas muaj cov pab pawg cyclic nrog cov neeg ua haujlwm complexing (central ion).
Chelates yog siv los cais, txheeb xyuas thiab tsom mus rau ntau yam ntsiab lus. Thiab hauv kev ua liaj ua teb thiab tshuaj, lawv tau siv los qhia cov micronutrients xws li manganese, hlau, tooj liab, thiab lwm yam rau hauv cov zaub mov.
Qee ntau dicarboxylic acids tsim cyclic anhydrides - tebchaw R1CO-O-COR2, uas yog cov tshuaj acylating nrog lub peev xwm. hnov mob nrog nucleophiles, electron-nplua nuj tshuaj.
Thiab qhov kawg ntawm dicarboxylic acids yog lawv tsim cov polymers (cov khoom hnyav molecular). Nws tshwm sim los ntawm qhov tshwm sim ntawm cov tshuaj tiv thaiv nrog rau lwm cov tshuaj polyfunctional.
Txoj kev tau txais
Muaj ntau ntawm lawv, thiab txhua tus ntawm lawv yog tsom rau kev sib txuas ntawm qee yam ntawm dicarboxylic acid. Tab sis muaj qee txoj hauv kev:
- Oxidation ntawm ketones - organic compounds nrog ib pawg carbonyl=CO.
- Hydrolysis ntawm nitriles. Ntawd yog, decomposition ntawm cov organic tebchaw nrog cov qauv R-C≡N nrog dej. Nitriles feem ntau yog cov khoom ua kua lossis cov kua dej uas muaj cov solubility zoo heev.
- Carbonylation ntawm diols - tshuaj nrog ob pawg hydroxyl. Cov tshuaj tiv thaiv muaj kev qhia txog C=O carbonyl pawglos ntawm reacting nrog carbon monoxide, ib tug heev toxic gas uas yog lighter tshaj huab cua thiab tsis muaj ntxhiab tsw los yog saj.
- Oxidation ntawm diols.
Ib yam ntawm cov txheej txheem no yuav ua rau tsim cov dicarboxylic acids. Muaj ntau ntawm lawv nyob rau hauv qhov xwm txheej. Txhua leej txhua tus paub cov npe ntawm lawv feem ntau, yog li nws tsim nyog hais luv luv txog lawv thiab.
Type of acids
thawj qhov uas yuav tsum nco ntsoov yog lawv txhua tus muaj ob lub npe:
- Systematic. Nws yog muab los ntawm lub npe ntawm alkane (acyclic hydrocarbon) nrog rau qhov sib ntxiv ntawm cov lus "-dioic".
- Ntshai. Muab los ntawm lub npe ntawm cov khoom ntuj tsim los ntawm cov kua qaub tau txais.
Thiab tam sim no ncaj qha txog kev sib txuas. Yog li, ntawm no yog qee qhov nrov tshaj plaws acids:
- Oxalic/ethandium. NOOS-COON. Muaj nyob rau hauv carambola, rhubarb, sorrel. Kuj tseem muaj xws li calcium thiab potassium oxalates (ntsev thiab esters).
- Malon/propandium. NOOS-CH2-COOH. Pom muaj hauv qab zib beet kua txiv.
- 2)2-COOH. Nws zoo li cov xim tsis muaj kob, zoo kawg nkaus soluble hauv cawv thiab dej. Pom nyob rau hauv amber thiab nyob rau hauv feem ntau cov nroj tsuag. Cov ntsev thiab esters ntawm hom dicarboxylic acid yog hu ua succinates.
- 2)3-COOH. Tau txais los ntawm oxidation ntawm cyclic ketone nrog nitric acid thiab kev koom tes ntawm vaniadium oxide.
- Adipic/Hexandioic. NOOS(CH2)4COOH. txaislos ntawm oxidation ntawm cyclohexane hauv ob kauj ruam.
YAmber/Butane. HOOS-(CH
YGlutaric/Pentandioic. HOOC-(CH
Ntxiv rau qhov saum toj no, tseem muaj heptanedioic acid, nonanedioic, decandioic, undecanedioic, dodecanedioic, tridecandioic, hexadecandioic, heneicosandioic thiab ntau lwm tus.
Aromatic dicarboxylic acids
Ob peb lo lus kuj yuav tsum tau hais txog lawv. Phthalic acids yog cov neeg sawv cev tseem ceeb tshaj plaws ntawm pab pawg no. Lawv tsis yog cov khoom lag luam tseem ceeb, tab sis lawv txaus siab. Txij li thaum lawv tau tsim los ntawm kev tsim cov phthalic anhydride - ib yam khoom uas dyes, resins thiab qee cov tshuaj ntawm cov tshuaj yog synthesized.
Muaj teraphlic acid. Nws, cuam tshuam nrog cawv, muab esters - derivatives ntawm oxo acids. Nws yog nquag siv hauv kev lag luam. Nrog kev pab los ntawm teraflic acid, saturated polyesters tau txais. Thiab lawv tau siv rau hauv kev tsim cov thawv ntim khoom noj, zaj duab xis rau video, yees duab, kaw suab, lub raj mis rau haus, thiab lwm yam.
Nws yuav tsum tau muab sau tseg thiab isophthalic aromatic acid. Nws yog siv raws li ib tug comonomer - ib tug tsawg molecular yuag khoom uas tsim ib tug polymer raws li ib tug tshwm sim ntawm ib tug polymerization cov tshuaj tiv thaiv. Cov cuab yeej no yog siv rau hauv kev tsim cov roj hmab thiab yas. Nws kuj yog siv los ua cov ntaub ntawv insulating.
Daim ntawv thov
Ib lo lus kawg txog qhov no. Yog tias peb tham txog kev siv cov dibasic carboxylic acids, ces nws tsim nyog sau cia tias:
- Lawv yog cov khoom siv raw, sivuas tsim cov kua qaub halides, ketones, vinyl ethers thiab lwm yam tseem ceeb organic compounds.
- Qee cov kua qaub tau koom nrog hauv kev tsim cov esters, uas yog siv ntxiv rau hauv perfumery, textile kev lag luam, tawv lag luam.
- Qee ntawm lawv muaj nyob rau hauv cov tshuaj tua kab mob thiab cov kuab tshuaj.
- Kev tsim cov capron, cov khoom siv hluavtaws polyamide, yog qhov tseem ceeb yam tsis muaj lawv.
- Qee cov kua qaub kuj siv los ua cov thermoplastic hu ua polyethylene terephthalate.
Txawm li cas los xij, cov no tsuas yog qee qhov chaw xwb. Muaj ntau lwm qhov chaw uas tshwj xeeb ntawm dibasic acids siv. Oxalic, piv txwv li, yog siv los ua mordant hauv kev lag luam. Los yog raws li ib tug precipitator rau hlau coatings. Suberic koom nrog hauv kev sib xyaw ntawm cov tshuaj. Azelaic yog siv los ua polyesters siv nyob rau hauv zus tau tej cov roj-resistant hluav taws xob cords, hoses thiab pipelines. Yog li, yog tias koj xav txog nws, muaj qee qhov chaw uas cov dibasic acids tsis pom lawv siv.
