Qhov Tseem Ceeb Qhov txawv - Hyperconjugation vs Resonance
Hyperconjugation thiab resonance tuaj yeem ruaj khov polyatomic molecules lossis ions hauv ob txoj kev sib txawv. Cov kev cai rau ob txoj kev no txawv. Yog hais tias ib tug molecule muaj ntau tshaj ib tug resonance qauv, lub molecule muaj lub resonance stabilization. Tab sis, hyperconjugation tshwm sim nyob rau hauv lub xub ntiag ntawm ib tug σ-bond nrog ib tug nyob ib sab khoob los yog ib nrab puv p-orbital los yog ib tug π-orbital. Qhov no yog qhov sib txawv tseem ceeb Hyperconjugation thiab Resonance
Hyperconjugation yog dab tsi?
Kev sib cuam tshuam ntawm cov hluav taws xob hauv σ-bond (feem ntau C-H lossis C-C daim ntawv cog lus) nrog cov khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob. Qhov kev sib cuam tshuam ruaj khov no yog hu ua 'hyperconjugation. Raws li txoj kev xav valence bond, qhov kev sib cuam tshuam no tau piav qhia tias yog 'ob daim ntawv cog lus tsis muaj daim ntawv cog lus resonance'.
Schreiner Hyperconjugation
Resonance yog dab tsi?
Resonance yog txoj kev piav qhia delocalized electrons nyob rau hauv ib lub molecule los yog polyatomic ion thaum nws muaj peev xwm muaj ntau tshaj li ib tug Lewis qauv los qhia cov qauv kev sib raug zoo. Ntau cov qauv tsim tuaj yeem siv los sawv cev rau cov khoom siv hluav taws xob delocalized hauv cov molecule lossis ib qho ion, thiab cov qauv no hu ua resonance structures. Tag nrho cov qauv kev txhawb nqa tuaj yeem ua piv txwv siv tus qauv Lewis nrog cov lej suav tau ntawm covalent bonds los ntawm kev faib cov electron khub ntawm ob lub atoms hauv daim ntawv cog lus. Txij li ob peb cov qauv Lewis tuaj yeem siv los sawv cev rau cov qauv molecular. Cov qauv molecular tiag tiag yog qhov nruab nrab ntawm tag nrho cov qauv Lewis. Nws yog hu ua resonance hybrid. Tag nrho cov qauv tsim muaj cov nuclei nyob rau hauv tib txoj hauj lwm, tab sis kev faib ntawm electrons tuaj yeem sib txawv.
YPhenol resonance
Qhov txawv ntawm Hyperconjugation thiab Resonance yog dab tsi?
yam ntxwv ntawm Hyperconjugation thiab Resonance
Hyperconjugation
Hyperconjugation cuam tshuam rau daim ntawv cog lus ntev, thiab nws ua rau luv luv ntawm sigma bonds (σ bonds)
| Molecule | C-C daim ntawv cog lus ntev | Yog vim li cas |
| 1, 3-Butadiene | 1.46 A | Ib txwm sib txuas ntawm ob qhov alkenyl. |
| Methylacetylene | 1.46 A | Hyperconjugation ntawm alkyl thiab alkynyl qhov |
| Methane | 1.54 A | Nws yog ib qho saturated hydrocarbon uas tsis muaj hyperconjugation |
Molecules nrog hyperconjugation muaj txiaj ntsig ntau dua rau qhov kub ntawm kev tsim piv rau cov lej ntawm lawv cov nyiaj tau los. Tab sis, qhov kub ntawm hydrogenation ib ob daim ntawv cog lus tsawg dua li ntawm ethylene
Qhov kev ruaj ntseg ntawm carbocations txawv nyob ntawm seb muaj pes tsawg tus C-H daim ntawv cog lus txuas rau cov pa roj carbon atom zoo. Lub hyperconjugation stabilization yog ntau dua thaum muaj ntau C-H daim ntawv cog lus txuas
(CH3)3C+ > (CH3)2CH+ > (CH3)CH 2+ > CH3+
txheeb ze hyperconjugation lub zog nyob ntawm isotope hom Hydrogen. Hydrogen muaj lub zog ntau dua piv rau Deuterium (D) thiab Tritium (T). Tritium muaj peev xwm tsawg tshaj plaws los qhia hyperconjugation ntawm lawv. Lub zog yuav tsum tau tawg C-T daim ntawv cog lus > C-D daim ntawv cog lus > C-H daim ntawv cog lus, thiab qhov no ua rau nws yooj yim dua rau H rau hyperconjugation
Resonance
