Qhov sib txawv tseem ceeb ntawm cawv thiab phenols yog tias cov cawv yog cov organic sib txuas uas muaj -OH pawg ua cov khoom tseem ceeb thaum cov phenols yog ib pawg cawv uas muaj -OH pawg thiab lub nplhaib benzene ua cov khoom tseem ceeb.
Muaj aliphatic thiab aromatic compounds nyob rau hauv cov organic chemistry, uas qhia tib pab pawg ua haujlwm. Tab sis, lawv cov khoom yuav txawv ntawm ib leeg vim yog aromaticity lossis aliphatic xwm. Cawv yog cov organic tebchaw uas muaj -OH pab pawg ua haujlwm. Phenol yog ib pawg ntawm cawv. Tshwj xeeb, nws muaj ib pawg -OH txuas nrog lub nplhaib uas muaj ntxhiab. Yog li ntawd, nws muaj qee yam khoom sib txawv, tsis zoo li feem ntau lwm yam cawv.
Alcohols yog dab tsi?
Tus yam ntxwv ntawm tsev neeg cawv yog muaj -OH ua haujlwm pab pawg (hydroxyl pawg). Feem ntau, pawg -OH no txuas rau sp 3 hybridized carbon. Cov tswv cuab yooj yim ntawm tsev neeg no yog methyl cawv, uas peb hu ua methanol. Peb tuaj yeem faib cov cawv ua peb pawg ua thawj, theem nrab thiab qib kaum. Ntawm no, qhov kev faib tawm no nyob ntawm qib kev hloov pauv ntawm cov pa roj carbon uas cov pawg hydroxyl txuas ncaj qha.
Yog tias cov pa roj carbon tsuas muaj lwm cov pa txuas nrog nws, peb lub npe nws ua cov pa roj carbon monoxide thiab cawv yog thawj cov cawv. Ib yam li ntawd, yog tias cov pa roj carbon nrog cov pab pawg hydroxyl txuas rau ob lwm cov pa roj carbon monoxide, ces qhov ntawd yog cov cawv thib ob thiab lwm yam. Peb lub npe cawv nrog lub ntsiab lus -ol raws li IUPAC nomenclature. Ua ntej, peb yuav tsum xaiv cov kab txuas txuas txuas ntev tshaj plaws uas cov pawg hydroxyl txuas ncaj qha. Tom qab ntawd peb yuav tsum tau hloov lub npe ntawm qhov sib thooj alkane los ntawm kev xa cov ntawv kawg e thiab ntxiv cov lus ol.
Properties
Ntxiv mus, cawv muaj qhov kub hnyiab ntau dua li cov hydrocarbons lossis ethers. Qhov laj thawj yog qhov muaj kev sib cuam tshuam ntawm cov molecular ntawm cov molecules los ntawm hydrogen bonding. Yog tias cov pab pawg R me me, cov cawv yog miscible nrog dej. Tab sis raws li pawg R tau loj dua, nws dhau los ua hydrophobic. Ntxiv mus, cov molecules yog polar. Nyob ntawd, C-O daim ntawv cog lus thiab O-H daim ntawv cog lus ua rau lub polarity ntawm cov molecule. Lub polarization ntawm O-H daim ntawv cog lus ua rau hydrogen ib feem zoo thiab piav qhia txog acidity ntawm cawv.
Daim duab 01: Cawv Cawv
Tsis tas li ntawd, cov no yog cov acids tsis muaj zog, thiab cov kua qaub yog ze rau cov dej. Vim hais tias, -OH yog ib pab neeg pluag tawm txij li OH– yog lub hauv paus muaj zog. Tab sis, protonation ntawm cawv hloov cov neeg pluag tawm hauv pawg -OH, mus rau hauv pab pawg tawm zoo (H2O). Cov pa roj carbon, uas ncaj qha txuas nrog -OH pawg, yog ib feem zoo; Yog li ntawd, nws yog susceptible rau nucleophilic nres. Tsis tas li ntawd, cov electron khub ntawm cov pa atom ua rau nws ob qho tib si hauv paus thiab nucleophilic.
Phenols yog dab tsi?
Phenol yog ib qho uas muaj ntxhiab hydrocarbon thiab ib tug derivative ntawm benzene. Phenol yog dawb crystalline khoom nrog molecular mis C6H6OH. Nws yog flammable thiab muaj ib tug muaj zog tsw. Qhov hnyav molecular ntawm no molecule yog 94 g mol-1 Lub melting point yog 40.5 oC, thiab kub taw tes yog 181 oC. Ntxiv mus, qhov ceev yog 1.07 g cm-3
Daim duab 02: 2D Cov Qauv ntawm Phenol
Yog li no, hauv cov txheej txheem tsim, hydrogen atom hauv benzene molecule hloov nrog ib pawg -OH, muab phenol. Yog li ntawd, nws muaj qhov zoo sib xws ntawm lub nplhaib nplhaib zoo li hauv benzene. Tab sis nws cov khoom sib txawv vim yog pawg -OH. Phenol yog me ntsis acidic (acidic dua li cawv). Thaum nws poob cov hydrogen ntawm -OH pab pawg nws tsim cov phenolate ion, thiab nws dhau mus resonance stabilization, uas nyob rau hauv lem ua phenol ib tug kuj zoo acid. Tsis tas li ntawd, nws yog me ntsis soluble hauv dej, vim tias nws tuaj yeem tsim hydrogen bonds nrog dej. Txawm li cas los xij, phenol evaporates qeeb dua dej.
Qhov txawv ntawm Cawv thiab Phenols yog dab tsi?
Cawv yog cov organic tebchaw uas muaj -OH pab pawg ua haujlwm. Phenol yog ib qho muaj ntxhiab hydrocarbon thiab derivative ntawm benzene. Nws kuj yog hom cawv. Yog li ntawd, qhov sib txawv tseem ceeb ntawm cov cawv thiab phenols yog cov cawv yog cov organic tebchaw uas muaj -OH pawg uas yog cov khoom tseem ceeb thaum cov phenols yog ib pawg cawv uas muaj -OH pawg thiab lub nplhaib benzene ua cov khoom tseem ceeb.
Raws li lwm qhov sib txawv tseem ceeb ntawm cawv thiab phenols, feem ntau, -OH ntawm cawv txuas mus rau ib qho sp3 hybridized carbon thaum nyob hauv phenol, nws txuas rau sp 2 hybridized carbon. Ntxiv mus, phenols yog cov kua qaub ntau dua li cawv.
Hauv qab no yog cov ntaub ntawv qhia txog qhov sib txawv ntawm cawv thiab phenols.
Summary – Alcohols vs Phenols
Cawv yog cov organic sib txuas. Phenol yog ib hom cawv nrog qee cov yam ntxwv. Qhov sib txawv tseem ceeb ntawm cov cawv thiab phenols yog tias cov cawv yog cov organic sib txuas uas muaj -OH pawg uas yog cov khoom tseem ceeb thaum cov phenols yog ib pawg cawv uas muaj -OH pawg thiab lub nplhaib benzene ua cov khoom tseem ceeb.
