H CH2 CH2Cl IUPAC: Ethyne IUPAC: 3-Chloropropyne IUPAC: 1-Chloro-2-butyne Common; acetylene (3-氯丙炔) (1-氯-2-丁炔) 乙炔) 八 Acetylenic hydrogen乙炔氢 R—C≡c—H a terminal alkyne末端炔烃 H3C—C=C: The propynide ion丙炔负离子
H CH2Cl IUPAC: Ethyne Common; acetylene (乙炔 ） IUPAC: 3-Chloropropyne (3-氯 丙 炔 ） CH2Cl IUPAC: 1-Chloro-2-butyne (1-氯 -2-丁 炔 ） H R C C H Acetylenic hydrogen 乙 炔 氢 A terminal alkyne 末 端 炔 烃 H3 C C C: - The propynide ion 丙 炔 负 离 子
8.4 Physical properties of alkenes and alkynes 8.5 Hydrogenation of alkenes Ni Pd or pt H2C=CH2 H -Ch3 CH 25°C H2c=CH—cH3+H2 CH3 CH2CH an addition reaction(加成反应) Reduction(还原反应) Catalytic hydrogenation(催化氢化)
8.4 Physical properties of alkenes and alkynes 8.5 Hydrogenation of alkenes H2 C CH2 + H2 CH3 CH3 H2 C CH CH3 + H2 CH3 CH2 CH3 Ni, Pd or Pt 25 o C an addition reaction（ 加 成 反 应 ） Reduction (还 原 反 应 ） Catalytic hydrogenation (催 化 氢 化 ）
8.6 Hydrogenation: The function of the catalyst Ni Pd or pt R—Hc=CH R—Hc=cH—R 25°C Catalytic hydrogenation(催化氢化) No cat △G(1)>△G(2) △G(2 R-HC=CH-R+H R—CH CH R △H 30 Kcal mol Reaction coordinate
8.6 Hydrogenation: The function of the catalyst HC CH + H2 Catalytic hydrogenation (催 化 氢 化 ） R R Cat No cat R CH2 CH2 R H o = - 30kcal mol -1 Reaction coordinate PE G(1) G(2) G(1) G(2) HC CH + H2 Ni, Pd or Pt 25 oC R R R HC CH R
Catalytic hydrogen and Syn addition H H Surface of metal catalyst H H C H H H H H H H
Catalytic hydrogen and Syn-- addition Surface of metal catalyst + H2 H H H H H H + H H C H H H H H H H H H H H H H H H H
8. 6a Syn and anti additions A Syn addition X—Y X An anti addition X—Y X
8.6A Syn and anti additions + X Y X Y A Syn addition + X Y X Y An anti addition