270 CHAPTER 7 Electron Delocalization and Resonance• More About Molecular Orbital Theoryδ+resonance contributorsresonance hybridresonance contributorsresonance hybridCH 3 CH CHCH 3CHCH 3CH CH CHCH 3+
CH 3 CH+resonance contributorsCH 3 CH CH
resonance hybridresonance contributorsresonance hybridCH 2resonance contributorsCH 3 CH CH CH CH CH 2+++++resonance contributorsδ+ δδ++δ+resonance hybridCH 3 CH CH
resonance hybridCH CHδ+δδ++δδ++ δδ++δδ++δδ++ δδ++CH 2 CH 2 CH 2 CH 2+
CH 2CH 3 CH CH 2CH 2CH CH CH 3 CH++
CH CH CH CH CH 2Figure 7.2
Resonance contributors are
obtained by moving electrons
toward a positive charge.presonance hybridresonance contributorsCH 2 CH
resonance hybridCH CH 2CH 2 CH 2− + + −
CHresonance contributorsCH H 2 CCHresonance contributorsresonance hybridCH CH 2 CH 2 CH CH CH 2resonance hybridresonance contributorsresonance contributorsresonance hybridFigure 7.3N
Resonance contributors are
obtained by moving electrons
toward a bond. (In the
second example, the red arrows
lead to the resonance
contributor on the right, and
the blue arrows lead to the
resonance contributor on the
left.)ppThe electrons can be moved in one of the following ways:- Move electrons toward a positive charge or toward a bond (Figures 7.2
and 7.3). - Move lone-pair electrons toward a bond (Figure 7.4).
- Move a single nonbonding electron toward a bond (Figure 7.5).p
pp pBRUI07-263_297r4 21-03-2003 11:31 AM Page 270