light or ROOR CH2=CHCH,CH,CH3 CH,=CHCHCH,CH3+ CCl4 3-Bromopentene pentene N-Bromosuccinimide (NBS) Su succinimide insoluble in CCl4 light or roor CCI Cyclohexene N-Bromosuccinimide 3-Bromocyclohexene Succinimide (NBS) insoluble in CCI4
+ N O O Br N-Bromosuccinimide (NBS) light or ROOR CCl4 + NH O O pentene 3-Bromopentene Succinimide insoluble in CCl4 CH2=CHCH2CH2CH3 CH2=CHCHCH2CH3 Br + N O O Br N-Bromosuccinimide (NBS) light or ROOR CCl 4 + NH O O Cyclohexene 3-Bromocyclohexene Succinimide insoluble in CCl 4 Br
12.3 The stability of the allyl radical (烯丙基自由基的稳定性) 12.3A Molecular orbital description of the allyl radical H2C-ATWHH2c 小H
12.3 The stability of the allyl radical (烯丙基自由基的稳定性） 12.3A Molecular orbital description of the allyl radical C H C H H H H2C sp 2 C H H H2C sp 2 sp 2 sp 2 H H2 C H C C H H
The molecular orbital of the allyl radica Node node H antibonding orbital ↑↑↑ nonbonding E orbital Three isolated p orbitals (with an elctron in each) Bonding orbital H
The molecular orbital of the allyl radical H2C H C C H H H2C H C C H H H2C H H Bonding orbital Nonbonding orbital Three isolated p orbitals (with an elctron in each) antibonding orbital E Node Node
12.3B Resonance description of the ally radical (烯丙基自由基的共振论的描述) 123 H2C=G—CH2 2CH CH2
12.3B Resonance description of the allyl radical (烯丙基自由基的共振论的描述） H2 C C H CH2 H2 C C H CH2 1 2 3 1 2 3
12.5 Summary of rules for resonance 12.5A Rules for writing resonance structures 1. Resonance stuctures exist only on paper. 2. In writing resonance structures we are only allowed to move electrons 23 H1C=C—ch H1C♀=cHt CH3 CHCH=CH,2 chrCHCHCH CH,=CH
12.5 Summary of rules for resonance 12.5A Rules for writing resonance structures 1. Resonance stuctures exist only on paper. 2. In writing resonance structures we are only allowed to move electrons. H2 C C H CH2 H2 C C H CH2 1 2 3 1 2 3 + + CH3 CHCH=CH2 CH3 CH=CHCH2 + CH2 CH2 CH=CH2