乙烯的键长和键角 H H 134pm 109pm C、21167 H121.6°H 烷烃C-C154pmC-H110pm ∠CCC1093° o A carbon-carbon double bond is both stronger 2 and shorter than a carbon-carbon single bond
Organic Chemistry Organic Chemistry Xiamen Xiamen University University 乙烯的键长和键角 C H H C H H 116.7 121.6 134pm 109pm 烷烃 C C 154 pm C H 110 pm CCC 109.3 A carbon-carbon double bond is both stronger and shorter than a carbon-carbon single bond
Cis-Trans Isomerism in Alkenes 顺反异构 相同基团在双键同侧为顺式,不同侧为反式 CH CHCH C-C H H H CH 顺式(cis) 反式 trans)
Organic Chemistry Organic Chemistry Xiamen Xiamen University University Cis-Trans Isomerism in Alkenes 顺反异构—— 相同基团在双键同侧为顺式 不同侧为反式 C C CH 3 H CH 3 H C C H CH 3 CH 3 H 顺式(cis ) 反式(tra n s )
The E,Z Designation CH CH gz,E异构 根据次序规则,较 大基团在同侧为 Z-型 Z型,不同侧为 E-型 CH H C=C CH E-型
Organic Chemistry Organic Chemistry Xiamen Xiamen University University The E, Z Designation C C CH 3 H CH 3 H C C H CH 3 CH 3 H Z − 型 E − 型 Z, E异构—— 根据次序规则 较 大基团在同侧为 Z – 型 不同侧为 E – 型
CH Br CH Br C-C C-C CH CH2Ch Z-型 Z-型 e(chruCH ch2 Ch3 CH3 C-C CH, CH3 h CH2CH E-型 E-型
Organic Chemistry Organic Chemistry Xiamen Xiamen University University C C Br CH 3 CH 3 H C C Br CH 2CH 3 CH 3 H C C CH 3 CH 2CH 3 (C H 3 ) 2CH H Z − 型 Z − 型 E − 型 C C CH 3 CH 2CH 3 CH 3 H E − 型
Alkene Stability CH H Acid CH CH3 C-C CH, catalyst H 反式 trans 顺式(ci 76 249 cis-2-Butene is less stable than trans-2-butene by 2.6 kJ/mol at room temperature
Organic Chemistry Organic Chemistry Xiamen Xiamen University University Alkene Stability C C CH 3 H CH 3 H 顺式(cis) C C H CH 3 CH 3 H 反式(tran s ) Ac i d catalyst 76% 24% cis-2-Butene is less stable than trans-2-butene by 2.6 kJ/mol at room temperature