International Nomenclature ntawm alkanes. Alkanes: qauv, zog

Nws tseem pab tau mus pib nrog ib tug txhais ntawm alkanes. Qhov no nyeem los yog nyeem hydrocarbons, paraffins. Peb kuj hais tau tias nws carbons nyob rau hauv uas compound C atoms yog ua los ntawm txoj kev yooj yim kev sib raug zoo. Cov kev mis yog ib yam uas rau hauv daim ntawv: CnH₂n + 2.

Nws yog lub npe hu hais tias tus piv ntawm H thiab C atoms nyob rau hauv lawv cov molecules li sai tau thaum piv rau lwm yam kawm ntawv. Muab hais tias tag nrho cov valences yog nyob hauv los yog C, los yog H, thiab tshuaj thaj chaw ntawm alkanes qhia luj lug txaus, li ntawd, lawv cov thib ob lub npe protrudes kab lus txwv los nyeem hydrocarbons.

muaj kuj yog ib tug ntau ancient lub npe uas zoo tshaj plaws qhia lawv tus txheeb ze himinertnost - paraffins, uas txhais txhais hais tias "tsis affinity".

Yog li ntawd, lub npe ntawm peb cov niaj hnub no sib tham: "Alka: homologous series, nomenclature, qauv, isomerism". Yuav kuj tam sim no cov ntaub ntawv hais txog lawv lub zog.

Alkanes: qauv, nomenclature

Nyob rau hauv cov C atoms yog nyob rau hauv xws li ib tug lub xeev raws li SP3-hybridization. Yog li ntawd alkane molecule yuav pom hais tias nws raws li ib tug txheej ntawm tetrahedral lug C, uas yog kev cob cog rua tsis tau tsuas yog ntawm lawv tus kheej tab sis kuj nrog H.

Ntawm C thiab H atoms yog tam sim no check, muaj tsawg kawg nkaus ncov qaumteb qabteb s-daim ntawv cog lus. Atoms nyob ib ncig ntawm ib bonds yeej ib txwm tig raws li ib tug rau txim ntawm alkanes molecules coj txawv cov ntaub ntawv, nyob rau qhov ntev ntawm lub kev twb kev txuas, lub kaum sab xis ntawm lawv - yog constants. Cov ntaub ntawv, uas yog kev hloov mus rau hauv txhua lwm yam vim txoj kev sib hloov ntawm lub molecule, uas tshwm sim nyob ib ncig ntawm lub σ-bonds, xa mus rau raws li nws cov conformation.

Nyob rau hauv tus txheej txheem ntawm detachment los ntawm cov H atoms ntawm cov molecule ntaub ntawv ib tug 1-valent hais hu ua hydrocarbon radicals. Cov tebchaw no cov kev tshwm sim tsis tau tsuas yog organic tebchaw tab sis kuj inorganic. Yog hais tias Rho ob hydrogen atom los ntawm ib tug hydrocarbon molecule txwv, ib tug lijchoj 2-valence radicals.

Yog li alkanes yuav ua tau nomenclature:

• radial (qub version);
• Hloov (thoob ntiaj teb, systematic). Nws npaj los ntawm IUPAC.

Tshwj xeeb tshaj yog radial nomenclature

Nyob rau hauv rooj plaub thawj nomenclature alkanes yog yus raws li nram no:

1. Xav hydrocarbons li derivatives ntawm methane, uas yog pawg los ntawm 1 los yog ntau tshaj H atoms radicals.
2. Lub high degree ntawm yooj yim nyob rau hauv cov ntaub ntawv ntawm tsis heev tebchaw.

Nta ntawm hloov nomenclature

Hloov nomenclature alkane muaj cov nram qab nta:

1. Lub hauv paus rau lub npe - 1 cov pa roj carbon saw, thiab tshuav molecular tawg tsam no yog raws li substituents.
2. Yog hais tias muaj ntau yam zoo tib yam radicals ua ntej lawv lub npe qhia tus xov tooj (nruj me ntsis nyob rau hauv lus), thiab radical xov tooj sib cais los ntawm commas.

Science News for KIDS: nomenclature ntawm alkanes

Rau kom yooj yim, cov ntaub ntawv nyob rau hauv tabular daim ntawv.

Qhov saum toj no nomenclature alkanes muaj xws li cov npe dabneeg yog tsim (thawj 4 nqe lus ntawm lub series nyeem hydrocarbons).

Ntawm no nondeployed alkanes nrog 5 los yog ntau tshaj C tsim los ntawm cov Greek numerals atoms uas muaj kev cuam tshuam ib tug zauv ntawm atoms C. Yog li -en sr ntawd hais tias cov tshuaj yeeb dej caw ntawm ib tug xov tooj ntawm nyeem tebchaw.

Nyob rau hauv kos duab lub npe deployed alkanes raws li lub ntsiab saw yog xaiv ib tug uas muaj lub siab tshaj plaws pes tsawg tus ntawm atoms C. Nws yog suav kom cov substituents muaj qhov tsawg tshaj plaws pes tsawg tus. Nyob rau hauv cov ntaub ntawv ob tug los yog ntau tshaj chains sib npaug ntev yuav ib lub ntsiab uas muaj lub siab tshaj plaws pes tsawg tus ntawm substituents.

isomerism ntawm alkanes

Raws li hydrocarbon-founder ntawm ib tug xov tooj ntawm cov kev ua methane CH₄. Nrog txhua tus neeg sawv cev ntawm lub methane series cai nyob rau hauv sib piv rau lub yav dhau los methylene pab pawg neeg - CH₂. Qhov no qauv yuav tsum havzoov thoob plaws hauv lub series ntawm alkanes.

German tus paub txog Schill muab tso rau pem ib lub tswv yim mus rau npe rau lub xov tooj ntawm homologous. Txhais los ntawm cov Greek lub ntsiab lus "zoo sib xws, zoo ib yam li."

Yog li, lub homologous series - ib tug txheej ntawm lwm yam kev organic tebchaw muaj tib lub hom qauv uas nyob ze himsvoystvami. Homologs - cov mej zeej ntawm lub series. Homologous sib txawv - methylene pab pawg neeg los ntawm cov uas ob tug sib txawv uas nyob ib sab homologue.

Raws li hais yav tas los, tej muaj pes tsawg leeg ntawm lub roj nyeem hydrocarbon tej zaum yuav qhia los ntawm cov kev mis CnH₂n + 2. Yog li, raws li cov methane yog ib tug tswv cuab ntawm lub homologous series ntawm ethane - C₂H₆. Yuav kom deduce cov qauv ntawm cov methane, nws yog tsim nyog los hloov lub H atom ntawm lub 1 CH₃ (daim duab hauv qab no).

Tus qauv ntawm txhua tom ntej homologue yuav muab tau los ntawm cov saum toj no nyob rau hauv tib yam. Raws li ib tug tshwm sim ntawm ethane tsim hluav taws roj zeb - C₃H₈.

Yuav ua li cas yog isomers?

Yog yam uas muaj ib tug zoo tib yam zoo thiab ntau molecular muaj pes tsawg leeg (tib yam molecular mis) tab sis txawv tshuaj lug thiab muaj ntau himsvoystvami.

Tsiag ntawv los ntawm aforementioned hydrocarbons li parameter raws li lub kub kub: -0,5 ° - butane, -10 ° - isobutane. Qhov no hom ntawm isomerism xa mus rau raws li carbonaceous cev pob txha isomerism, nws koom lub yam ntxwv hom.

Cov nab npawb ntawm cov yam ntxwv isomers tsub kom sai heev nrog lub xov tooj ntawm cov pa roj carbon atoms. Yog li, C₁₀H₂₂ yuav sib isomers 75 (tsis xws li qhov chaw), thiab rau 4347 C₁₅H₃₂ twb paub isomers, rau C₂₀H₄₂ - 366.319.

Yog li ntawd twb nws yog tseeb hais tias xws li ib tug alkanes, homologous series, isomerism, nomenclature. Tam sim no nws yog tsim nyog los mus rau cov kev cai rau IUPAC npe.

IUPAC nomenclature: Lub npe ntawm txoj kev kawm ntawv

Firstly, nws yog tsim nyog los nrhiav tau ib tug qauv ntawm ib tug hydrocarbon carbon saw, uas muaj cov feem ntau ntev thiab lub siab tshaj plaws pes tsawg tus ntawm substituents. Ces yuav tsum tau tus xov tooj hauv cov saw hlau C atoms, pib los ntawm thaum kawg, uas yog ze substituent.

Secondly, lub hauv paus - lub npe ntawm tus unbranched nyeem hydrocarbon, uas sib raug rau tus xov tooj ntawm C atoms yog lub ntsiab saw.

Peb, ua ntej lub hauv paus yuav tsum qhia kom meej lokantov chav, uas yog nyob ze ntawm lub deputies. Lawv tau sau hyphenated lub npe alternates.

Fourthly, nyob rau hauv cov ntaub ntawv ntawm tib yam substituents rau txawv atoms C lokanty ua ke, nyob rau ua ntej lub npe tshwm multiplies prefix: di - ob tug zoo tib substituents peb - mus rau peb, Tetra - plaub, penta - mus rau tsib, thiab lwm yam nuj nqis .. lawv yuav tsum tau sib cais los ntawm ib tug tsis nco qab, thiab los ntawm cov lus - hyphen.

Yog hais tias ib tug thiab tib C atom muaj cia li muaj ob substituents lokant kuj kaw ob zaug.

Raws li cov kev cai, thiab tsim ib tug thoob ntiaj teb nomenclature ntawm alkanes.

Newman lub projection

Qhov no American tus paub txog pom muaj graphic ua qauv qhia conformations tshwj xeeb projection mis - Newman projection. Lawv sib haum mus rau cov ntaub ntawv A thiab B thiab C muaj qhia nyob rau hauv daim duab hauv qab no.

Nyob rau hauv thawj cov ntaub ntawv ntawm A-eclipsed conformation, thaum lub sij hawm thib ob - B-inhibited. Nyob rau hauv txoj hauj lwm A H atoms yog nyob rau ntawm ib tug tsawg kawg nkaus deb ntawm txhua lwm yam. Qhov no daim ntawv sau raws nkaus Ii qhov loj tshaj plaws nqi ntawm lub zog vim lub fact tias cov loj tshaj repulsion therebetween. Qhov no energetically unfavorable lub xeev, uas tus molecule nyhav tawm nws, thiab txav mus rau ib tug ntau ruaj khov txoj hauj lwm B. no lub H atoms ntawm lub siab tshaj plaws nyob deb li cas los ntawm txhua lwm yam. Yog li, lub zog qhov sib txawv ntawm cov kev cai - 12 kJ / mol, yog li ntawd free kev sib hloov nyob ib ncig ntawm lub axis ntawm lub molecule ethane, uas txuas lub methyl pawg tau sis tsis ncaj. Ib zaug hauv lub energetically paaj txoj hauj lwm ntawm lub molecule muaj yog ncua, nyob rau hauv lwm yam lus, lub "nres". Uas yog vim li cas nws yog hu ua ruamqauj. Tshwm -. 10 txhiab ethane molecules yog nyob rau hauv daim ntawv ntawm cov inhibited conformation muab chav tsev kub. Tsuas yog ib tug muaj ib tug txawv cov duab - eclipsed.

Kev npaj ntawm nyeem hydrocarbons

Los ntawm cov tsab xov xwm no nws twb kawm tau hais tias qhov no alkanes (qauv, nomenclature ntawm lawv piav nyob rau hauv kom meej yav tas los). Nws yuav superfluous mus xyuas lawv txoj kev ntawm kev npaj. Lawv rho tawm los ntawm tej yam ntuj tso qhov chaw xws li roj, nkev, txuam roj, thee. Tsis tas li ntawd thov hluavtaws txoj kev. Piv txwv li, H₂ 2H₂:

1. Tus txheej txheem ntawm hydrogenation ntawm unsaturated hydrocarbons: CnH₂n (alkenes) → CnH₂n + 2 (alkanes) ← CnH₂n-2 (alkynes).
2. Monoxide los ntawm ib tug sib tov ntawm C thiab H - syngas: Nco + (2n + 1) H₂ → CnH₂n + 2 + nH₂O.
3. Los ntawm carboxylic acids (ntsev thereof): electrolysis nyob rau anode mus rau lub cathode:

• Kolbe electrolysis: 2RCOONa + 2H₂O → R-R + 2CO₂ + H₂ + 2NaOH;
• Dumas cov tshuaj tiv thaiv (hlau nrog alkali): CH₃COONa + NaOH (t) → CH₄ + Na₂CO₃.

1. Ntes ntawm cov roj: CnH₂n + 2 (450-700 °) → CmH₂m + 2 + CN-mH₂ (nm).
2. Gasification ntawm roj (khoom): C + 2H₂ → CH₄.
3. Synthesis of complex alkanes (halogenated) uas muaj ib tug tsawg heev tooj ntawm atoms C: 2CH₃Cl (chloromethane) + 2Na → CH₃- CH₃ (ethane) + 2NaCl.
4. Expansion dej methanide (hlau carbides): Al₄C₃ + 12H₂O → 4Al (OH₃) ↓ + 3CH₄ ↑.

Lub cev thaj chaw ntawm nyeem hydrocarbons

Rau kom yooj yim, cov ntaub ntawv yog grouped nyob rau hauv lub rooj.

xaus

Cov tsab xov xwm mas suav hais tias xws li ib tug tshaj plaws li alkanes (qauv, nomenclature, isomerism, homologous series thiab thiaj li nyob.). Nws qhia rau peb ib tug me ntsis txog cov yam ntxwv ntawm radial thiab hloov nomenclatures. Txoj kev no yog piav rau muab alkanes.

Nyob rau hauv tas li ntawd, hauv tsab xov xwm uas tau teev tseg nyob rau hauv kom meej tag nrho cov nomenclature ntawm alkanes (test yuav pab tau rau assimilate cov ntaub ntawv).