1、第二章烷烴、環烷烴及其構象Alkanes, CycloalkanesAnd Their ConformationsOrganic ChemistryOrganic ChemistryXiamen UniversityXiamen University2.1 鏈烷烴AlkanesOrganic ChemistryOrganic ChemistryXiamen UniversityXiamen UniversityIntroduction to alkanes andcycloalkanesThe family of organic compoundscalled hydrocarbons can

2、 be dividedinto several groups on the basis ofthe type of bond that exists betweenthe individual carbon atoms.Organic ChemistryOrganic ChemistryXiamen UniversityXiamen UniversityAll of the carbon-carbon bonds aresingle bonds alkanesContain a carbon-carbon double bond alkenesWith a carbon-carbon trip

3、le bond alkynesCycloalkanes are alkanes in which allor some of the carbon atoms arearranged in a ring.Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University 鏈烷烴的結構及其同分異構現象Structure and isomerismOrganic ChemistryOrganic ChemistryXiamen UniversityXiamen University1. 幾個根本概念烴(Hydocarbons)飽

4、和烴(Saturated hydrocarbons)鏈烷烴的通式(General formula)CnH2n+2同系列(Homologous series)同系物(Homologs)Organic ChemistryOrganic ChemistryXiamen UniversityXiamen UniversityAlkanes are often described assaturated hydrocarbonsHydrocarbons because they contain onlycarbon and hydrogen.Saturated because they have onl

5、y CCand CH single bonds.Alkanes are also occasionally referred toas aliphatic compounds, a name derivedfrom the Greek aleiphas, meaning “fat.Organic ChemistryOrganic ChemistryXiamen UniversityXiamen UniversityStraight-chain alkanes (normal alkanes) carbons are connected in a row.Branched-chain alkan

6、es carbonchains branch.Isomers from Greek isos + merosmeaning “made of the same parts Isomers are compounds that have thesame numbers and kinds of atoms butthat differ in the way these atoms arearranged.Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University2. 烷烴的結構特征碳原子都是 sp3 雜化 ，呈四面體結

7、構鍵角約為109.5CC 鍵的平均鍵長為154pm，CH 鍵的平均鍵長為107pmHCHHHCHH109.5H109.5HOrganic ChemistryOrganic ChemistryXiamen UniversityXiamen University3. 烷烴的構象(Conformation)構象：由單鍵旋轉所產生的分子中原子或基團在空間的特定排列形式。構象異構體(Conformers)：由單鍵旋轉而產生的異構體。單鍵旋轉會產生無數個構象，它們互為構象異構體。Organic ChemistryOrganic ChemistryXiamen UniversityXiamen Univer

8、sityThe different arrangements of atomscaused by rotation about a single bondare called conformations, and aspecific conformation is called aconformer (conformation isomer).Unlike constitutional isomers, though,different conformers cant usually beisolated because they interconvert toorapidly.Organic

9、 ChemistryOrganic ChemistryXiamen UniversityXiamen University乙烷的構象構象式的表達方式：Newman 投影式(Newman projections)鋸架式( Sawhorse representations)傘式HHHHHHHHHHHHHHHHHHOrganic ChemistryOrganic ChemistryXiamen UniversityXiamen University重疊式構象與交叉式構象HHHHHHHHHHHH重疊式構象交叉式構象60O能量差 12.1 kJmol-1Organic ChemistryOrganic

10、ChemistryXiamen UniversityXiamen UniversityHHHHHH重疊式與交叉式構象的能量分析2.29 A鍵長：CH 1.07, CC 1.54 A鍵角：HCH 109.5重疊式兩個H之間距離：2.29 A氫原子半徑：H = 1.2 AOrganic ChemistryOrganic ChemistryXiamen UniversityXiamen University60120180240EHHHHHHHHHHHH乙烷不同構象的能量曲線圖重疊式構象交叉式構象HHHHHHHHHHHH12.1 kJ / mol旋轉角度Organic ChemistryOrgani

11、c ChemistryXiamen UniversityXiamen University丁烷的構象CH3HHHHCH3HHHHCH3CH360OCH3HHHCH3HHHCH3HCH3H60O60O60OHHCH3HHCH3HCH3HHHCH360O1全重疊式2鄰位交叉式3局部重疊式4對位交叉式5局部重疊式6鄰位交叉式Organic ChemistryOrganic ChemistryXiamen UniversityXiamen UniversityCH3HHH丁烷不同構象的能量曲線圖6012018024030036018.8 kJ/mol3.7 kJ/mol 15.9 kJ/molHHHH

12、HCH3CH3HHCH3CH3CH3HHHHHCH3CH3HCH3HHCH31H2CH3H34CH3H5H6HHHE H HCH3CH31 H旋轉角度Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University乙烷衍生物的構象分布衍生物ClCH2CH2ClBrCH2CH2BrPhCH2CH2Ph對位交叉所占比例(%)70849190一般情況下是對位交叉式 鄰位交叉式，但也有例外的情況發生。Xiamen UniversityXiamen UniversityOrganic ChemistryOrganic Chemist

13、ry鄰位交叉為主的特殊情況OHHHHClHOHHHHOHHOrganic ChemistryOrganic ChemistryXiamen UniversityXiamen University高級烷烴碳鏈呈鋸齒形HHH H H HHHHH H H H HZigZag geometryOrganic ChemistryOrganic ChemistryXiamen UniversityXiamen University 鏈烷烴的命名NomenclatureOrganic ChemistryOrganic ChemistryXiamen UniversityXiamen University 鏈

14、烷烴的命名1. 系統命名法2. 習慣命名法普通命名法3. 衍生物命名法4. 俗名Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University1. 系統命名法IUPAC命名法中文系統命名法(CCS)：由中國化學會根據IUPAC命名法的原那么，結合中文特點而制定的系統命名法化合物名稱的構成：立體化學名取代基名母體名Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University直鏈烷烴的命名按照分子中所含的碳原子數而稱為“某烷 碳原子數在十個以下的，用

15、天干甲、乙、丙、丁、戊、己、庚、辛、壬、癸來表示碳原子數在十個以上的，用中文數字十一、十二、十三來表示Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University支鏈烷烴的命名選主鏈母體編號取代基的編號、合并、列出次序* 取代基的列出次序在中英文命名中所依據的原那么不同，英文按取代基字母順序，中文按 “次 序 規 那么Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University主鏈及編號選擇含取代基多的最長碳鏈7 6 5 4 3 2 1CH3C

16、H2CH CH CH CHCH3CH3 CH2 CH3 CH3CH2CH32,3,5-三甲基-4-丙基庚烷CH3 CH3 CH32,2,3,5-四甲基己烷CH31 2 3CH3C CH6 5 44 5 6CH2 CHCH33 2 1最低系列原那么Organic ChemistryOrganic ChemistryXiamen UniversityXiamen UniversityCH3CH2 C1CH3CH33 2取代基相同的取代基合并，列出各取代基位號并用中文數字表示取代基數目；取代基上帶支鏈的，給支鏈編號，命名方式有2種：3 2CH3CH2 C CH310 9 8 7 6 5 4 3 2

17、1CH3CH2CH2CH2CH2 C CH2CH2CHCH3CH32-甲基5,5-二(1,1-二甲基丙基)癸烷2-甲基5,5-二-1,1-二甲基丙基癸烷Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University次序規那么次序規那么是為了表達某些化合物的立體化學關系而制定的判別原子或基團排列順序的方法中文系統命名法借用次序規那么來規定取代基在命名中的列出順序Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University次序規那么的主要內容原子序數

18、大的次序大，原子序數小的次序小，同位素中質量高的次序大 。I Br Cl S P F O N C DH如果原子團的第一個原子相同，那么比較與它相連的其它原子第二個原子的原子序數大小 ，其它依次類推 。含有雙鍵或叁鍵的原子團，可以認為連有二個或三個相同的原子 。Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University英文命名Alkane詞尾-aneAlkyl詞尾-ane -ylHeptaneOctaneNonaneDecaneUndecaneTridecaneMethaneEthanePropaneButanePen

19、taneHexaneOrganic ChemistryOrganic ChemistryXiamen UniversityXiamen University詞頭mono, di, tri, tetra, penta, hexan, iso, neosec, tert表示取代基個數的詞頭不參與字順排序, iso, neo 參與字順排序Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University取代基IUPAC保存了8個烷基的俗名:Isopropyl , isobutyl , sec-butyl , tert-butyl

20、, isopentyl , tert-pentyl , neopentyl ,isohexyl縮寫:Me methyl , Et ethyl ,Bu butyl ,Pr propyl ,Ph phenylOrganic ChemistryOrganic ChemistryXiamen UniversityXiamen UniversityIUPAC與CCS命名的差異CH3CH2CH CH CH CHCH3CH3CH3 CH2 CH3 CH37 6 5 4 3 2 12,3,5-三甲基-4-乙基庚烷4-Ethyl-2,3,5-trimethylheptaneOrganic ChemistryOr

21、ganic ChemistryXiamen UniversityXiamen University2. 習慣命名法普通命名法直鏈烷烴命名為正某烷帶支鏈的烷烴用“異, “新等區別CH3CH3 CCH3CH2CH3新戊烷CH3CH3CH CH2CH3異戊烷Organic ChemistryOrganic ChemistryXiamen UniversityXiamen UniversityCH3CHC衍生物命名法以甲烷為母體，其它為取代基命名CH3CH2CH2CH3CH3 CH3二甲基正丙基異丙基烷Organic ChemistryOrganic ChemistryXiamen Universit

22、yXiamen University俗名根據其來源而命名，如甲烷又稱沼氣Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University2. 1.3 烷烴的物理性質Physical Properties ofAlkanesOrganic ChemistryOrganic ChemistryXiamen UniversityXiamen University物理性質物理性質不需要發生化學變化就表現出來的性質外觀：狀態、顏色、氣味物理常數：mp , bp , nD , D , d4 , 溶解度Organic Chemistry

23、Organic ChemistryXiamen UniversityXiamen University2. 1.4 烷烴的化學性質Chemical Properties ofAlkanesOrganic ChemistryOrganic ChemistryXiamen UniversityXiamen University烷烴分子中只有碳碳，碳氫 -鍵，故十分穩定碳氫鍵的極性小，不易發生異裂，一般發生均裂Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University1. 烷烴的鹵化CH4+ Cl2hvCH3Cl HCl反

24、響機理 (Reaction mechanism)Cl22ClhvCH4 + ClCH3 Cl2Cl ClCH3 CH3CH3 ClCH3 HClCH3Cl ClCl2CH3CH3CH3Cl鏈引發鏈增長鏈終止Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University甲烷氯化反響的產物CH4 + Cl2hvCH3Cl CH2Cl2 +CHCl3 + CCl4CH3Cl + ClCH2Cl + Cl2CH2Cl + HClCH2Cl2 + ClOrganic ChemistryOrganic ChemistryXiamen

25、 UniversityXiamen University反響活性氯化和溴化是常用反響氟化反響大量放熱，難以控制碘化反響吸熱，反響很慢F2 Cl2 Br2 I2Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University反響的選擇性CH3CH2CH2CH3+ Cl2hv35hv35(CH3)2CHCH2Cl + (CH3)3CCl63% 37%CH3CHCH3 + Cl2CH3V(1 H)：V(3 H) = 63 / 9 ：37 / 1 =1：5.3V(1 H)：V(2 H) ： V(3 H) =1：4：5.3+ CH3

26、CH2CHCH3 72%ClV(1 H)：V(2 H) = 28 / 6 ：72 / 4 =1：4CH3CH2CH2CH2Cl 28%Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University溴化反響的選擇性hv127hv127CH3CH2CH3 + Br2CH3CHCH3 + Br2CH3CH3CH2CH2Br + CH3CHCH33% Br 97%(CH3)2CHCH2Br + (CH3)3CBr少量 99%V(1 H)：V(2 H) ： V(3 H) =1：82：1600溴化反響的選擇性更好Organic Ch

27、emistryOrganic ChemistryXiamen UniversityXiamen UniversityCH3CH2CH3 + HNO32. 烷烴的硝化和磺化氣相400 CCH3NO2 + CH3CH2NO2+ CH3CH2CH2NO2 + CH3CHCH3NO2CH3CH3 + HSO4400 CCH3CH2SO3HOrganic ChemistryOrganic ChemistryXiamen UniversityXiamen University3. 裂化和裂解裂化隔絕空氣加壓加熱(500700)，斷裂成小分子催化裂化在催化劑存在下的裂化，溫度較低(400500)CH3CH2

28、CH2CH3CH4 + CH3CH=CH2CH3CH3 + CH2=CH2CH3CH2CH=CH2 + H2500Organic ChemistryOrganic ChemistryXiamen UniversityXiamen UniversityCH3(CH2)5CH3CH3CH3CH3(CH2)3CHCH3CH3裂化伴隨脫氫、環化和異構化脫氫CH3(CH2)4CH=CH2 + H2環化異構化芳構化Xiamen UniversityXiamen UniversityOrganic ChemistryOrganic Chemistry異辛烷CH3CH3CH3 C CH2CHCH3CH3辛烷值

29、 100Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University裂解深度裂化(700)裂解的目的不是提高汽油的產量和質量，而是為了獲得更多的三烯、三苯、乙炔和萘這8種根本有機化工原料。三烯：乙烯、丙烯、丁二烯三苯：苯、甲苯、二甲苯Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University4. 氧化反響CH4 + 2 O2CnH2n+2 + O2CO2 + 2 H2O + 890 kJ / mol55.6 kJ / gCO2 + H2O50

30、 kJ / gOrganic ChemistryOrganic ChemistryXiamen UniversityXiamen University2.2 環烷烴CycloalkanesOrganic ChemistryOrganic ChemistryXiamen UniversityXiamen University 環烷烴的分類單環烷烴-只含一個環的環烷烴橋環烷烴-共用兩個或兩個以上碳原子的多環烷烴螺環烷烴-單環之間共用一個碳原子的多環烷烴集合環烷烴-環與環之間以單鍵直接相連的多環烷烴環烷烴Organic ChemistryOrganic ChemistryXiamen Univers

31、ityXiamen University 環烷烴的異構和命名1. 單環烷烴2. 橋環烴3. 螺環烴Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University1. 單環烷烴分類小環化合物 C3C4普通環化合物 C5C7中環化合物 C8C11大環化合物 C12Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University異構碳架異構、順反異構、旋光異構、構象異構順反異構：由于成環原子之間的單鍵不能自由旋轉而引起。兩個取代基在環平面同側為順式，不同側

32、為反式CH3HHCH3 HCH3HcisCH3transOrganic ChemistryOrganic ChemistryXiamen UniversityXiamen University命名(a) 沒有取代基: 在相應烷烴名稱前加“環(cyclo)(b) 有取代基：取代基簡單時以環為母體，取代基復雜時環做為取代基CH3HCH3HCH2CH3CH CH2CH2CH3順-1,4-二甲基環己烷cis-1,4-Dimethylcyclohexane3-環己基己烷3-CyclohexylhexaneOrganic ChemistryOrganic ChemistryXiamen Universit

33、yXiamen University2. 橋環烴的命名1. 確定母體烴2. 確定環數3. 選主環4. 選主橋5. 編號6. 確定方括號內數字7. 寫出完整的名稱環數方括號內數字母體烴名Organic ChemistryOrganic ChemistryXiamen UniversityXiamen UniversityCH2CH3123456CH3 7 CH34351 267CH2CH37,7-二甲基-2-乙基二環2.2.1庚烷2-Ethyl-7,7-dimethylbicyclo2.2.1heptane8三環2,4辛烷2,4octaneOrganic ChemistryOrganic Che

34、mistryXiamen UniversityXiamen University螺3.4辛烷Spiro3.4octane6氯螺4.5癸烷6-Chlorospiro4.5decane123132879Cl6510 47685 4Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University3. 螺環烴的命名1. 確定母體烴2. 確定螺數3. 編號4. 選主橋5. 編號6. 寫出完整的名稱螺數方括號內數字母體烴名Organic ChemistryOrganic ChemistryXiamen UniversityXiamen

35、 University螺3.4辛烷Spiro3.4octane6氯螺4.5癸烷6-Chlorospiro4.5decane123132879Cl6510 47685 4Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University環烷烴的物理性質自學Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University 環烷烴的化學性質Organic ChemistryOrganic ChemistryXiamen UniversityXiamen Uni

36、versity1. 加氫+ H2+ H2+ H250 Pt120Pt300PtCH3CH2CH3CH3CH2CH2CH3CH3CH2CH2CH2CH3Xiamen UniversityXiamen UniversityOrganic ChemistryOrganic Chemistry3002. 加鹵素室溫+ Br2+ Br2hv+ Br2BrCH2CH2CH2BrBr+ HBrBr+ HBrXiamen UniversityXiamen UniversityOrganic ChemistryOrganic Chemistry(主)3. 加鹵化氫+ HBrCH3CH2CH2Br+ HBrCH3

37、CH3CH2CHCH3BrOrganic ChemistryOrganic ChemistryXiamen UniversityXiamen University Baeyer張力學說張力學說的根底張力學說的內容張力學說的缺陷Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University 環烷烴的構象Xiamen UniversityXiamen UniversityOrganic ChemistryOrganic Chemistry1. 環己烷的構象椅式構象(chair form)2.51 Aequatorial12a

38、xial3456123456Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University兩種椅式構象123456123456構象轉換體Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University船式構象(boat form)12341.83 A6 53241562.27 A扭船式構象(twist form)Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University半椅式構象四種構象的變化過程Organic ChemistryOrganic ChemistryXiamen UniversityXiamen UniversityCH32.