1-40 continued (d) CH3-C- C=C- C= 日HH9 minor minor major-negative chae on electronegative atoms NOTE:The two structures below are resonance forms,varying from the first two structures in part (d)by cannot be overemphasized. ®-9 HHH:O: HHH:: NH @)CH,CH,-C-2。→CH,CH2-C-NH2→CH,CH,-C=, minor major-full octets major-full octets 1-41 equal energy [aH-9-日-a4一a4-G=8-c H no resonance stabilizatior more stable-resonance stabilized H (b) cn- -cH→8，-c=c-cH】 9 2=C- C-CH R H more stable -resonance stabilized no resonance stabilization H-cHs H- c三N:→H-c=C= no resonance stabilizatio more stable-resonance stabilized a-o no resonance stabilization esonance stabilized 21 Copyright2013 Pearson Education,Ine