1、第二章烷烴、環(huán)烷烴及其構(gòu)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(jié)構(gòu)及其同分異構(gòu)現(xiàn)象Structure and isomerismOrganic ChemistryOrganic ChemistryXiamen UniversityXiamen University1. 幾個(gè)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(jié)構(gòu)特征碳原子都是 sp3 雜化 ，呈四面體結(jié)

7、構(gòu)鍵角約為109.5CC 鍵的平均鍵長(zhǎng)為154pm，CH 鍵的平均鍵長(zhǎng)為107pmHCHHHCHH109.5H109.5HOrganic ChemistryOrganic ChemistryXiamen UniversityXiamen University3. 烷烴的構(gòu)象(Conformation)構(gòu)象：由單鍵旋轉(zhuǎn)所產(chǎn)生的分子中原子或基團(tuán)在空間的特定排列形式。構(gòu)象異構(gòu)體(Conformers)：由單鍵旋轉(zhuǎn)而產(chǎn)生的異構(gòu)體。單鍵旋轉(zhuǎn)會(huì)產(chǎn)生無數(shù)個(gè)構(gòu)象，它們互為構(gòu)象異構(gòu)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(gòu)象構(gòu)象式的表達(dá)方式：Newman 投影式(Newman projections)鋸架式( Sawhorse representations)傘式HHHHHHHHHHHHHHHHHHOrganic ChemistryOrganic ChemistryXiamen UniversityXiamen University重疊式構(gòu)象與交叉式構(gòu)象HHHHHHHHHHHH重疊式構(gòu)象交叉式構(gòu)象60O能量差 12.1 kJmol-1Organic ChemistryOrganic

10、ChemistryXiamen UniversityXiamen UniversityHHHHHH重疊式與交叉式構(gòu)象的能量分析2.29 A鍵長(zhǎng)：CH 1.07, CC 1.54 A鍵角：HCH 109.5重疊式兩個(gè)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(gòu)象的能量曲線圖重疊式構(gòu)象交叉式構(gòu)象HHHHHHHHHHHH12.1 kJ / mol旋轉(zhuǎn)角度Organic ChemistryOrgani

11、c ChemistryXiamen UniversityXiamen University丁烷的構(gòu)象CH3HHHHCH3HHHHCH3CH360OCH3HHHCH3HHHCH3HCH3H60O60O60OHHCH3HHCH3HCH3HHHCH360O1全重疊式2鄰位交叉式3局部重疊式4對(duì)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(gòu)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(zhuǎn)角度Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University乙烷衍生物的構(gòu)象分布衍生物ClCH2CH2ClBrCH2CH2BrPhCH2CH2Ph對(duì)位交叉所占比例(%)70849190一般情況下是對(duì)位交叉式 鄰位交叉式，但也有例外的情況發(fā)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(jí)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(tǒng)命名法2. 習(xí)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(tǒng)命名法IUPAC命名法中文系統(tǒng)命名法(CCS)：由中國(guó)化學(xué)會(huì)根據(jù)IUPAC命名法的原那么，結(jié)合中文特點(diǎn)而制定的系統(tǒng)命名法化合物名稱的構(gòu)成：立體化學(xué)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(shù)而稱為“某烷 碳原子數(shù)在十個(gè)以下的，用

15、天干甲、乙、丙、丁、戊、己、庚、辛、壬、癸來表示碳原子數(shù)在十個(gè)以上的，用中文數(shù)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(hào)取代基的編號(hào)、合并、列出次序* 取代基的列出次序在中英文命名中所依據(jù)的原那么不同，英文按取代基字母順序，中文按 “次 序 規(guī) 那么Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University主鏈及編號(hào)選擇含取代基多的最長(zhǎng)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(hào)并用中文數(shù)字表示取代基數(shù)目；取代基上帶支鏈的，給支鏈編號(hào)，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(guī)那么次序規(guī)那么是為了表達(dá)某些化合物的立體化學(xué)關(guān)系而制定的判別原子或基團(tuán)排列順序的方法中文系統(tǒng)命名法借用次序規(guī)那么來規(guī)定取代基在命名中的列出順序Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University次序規(guī)那么的主要內(nèi)容原子序數(shù)

18、大的次序大，原子序數(shù)小的次序小，同位素中質(zhì)量高的次序大 。I Br Cl S P F O N C DH如果原子團(tuán)的第一個(gè)原子相同，那么比較與它相連的其它原子第二個(gè)原子的原子序數(shù)大小 ，其它依次類推 。含有雙鍵或叁鍵的原子團(tuán)，可以認(rèn)為連有二個(gè)或三個(gè)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(gè)數(shù)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(gè)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(xí)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(qū)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(jù)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(zhì)Physical Properties ofAlkanesOrganic ChemistryOrganic ChemistryXiamen UniversityXiamen University物理性質(zhì)物理性質(zhì)不需要發(fā)生化學(xué)變化就表現(xiàn)出來的性質(zhì)外觀：狀態(tài)、顏色、氣味物理常數(shù)：mp , bp , nD , D , d4 , 溶解度Organic Chemistry

23、Organic ChemistryXiamen UniversityXiamen University2. 1.4 烷烴的化學(xué)性質(zhì)Chemical Properties ofAlkanesOrganic ChemistryOrganic ChemistryXiamen UniversityXiamen University烷烴分子中只有碳碳，碳?xì)?-鍵，故十分穩(wěn)定碳?xì)滏I的極性小，不易發(fā)生異裂，一般發(fā)生均裂Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University1. 烷烴的鹵化CH4+ Cl2hvCH3Cl HCl反

24、響機(jī)理 (Reaction mechanism)Cl22ClhvCH4 + ClCH3 Cl2Cl ClCH3 CH3CH3 ClCH3 HClCH3Cl ClCl2CH3CH3CH3Cl鏈引發(fā)鏈增長(zhǎng)鏈終止Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University甲烷氯化反響的產(chǎn)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(huán)化和異構(gòu)化脫氫CH3(CH2)4CH=CH2 + H2環(huán)化異構(gòu)化芳構(gòu)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(chǎn)量和質(zhì)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(jī)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(huán)烷烴CycloalkanesOrganic ChemistryOrganic ChemistryXiamen UniversityXiamen University 環(huán)烷烴的分類單環(huán)烷烴-只含一個(gè)環(huán)的環(huán)烷烴橋環(huán)烷烴-共用兩個(gè)或兩個(gè)以上碳原子的多環(huán)烷烴螺環(huán)烷烴-單環(huán)之間共用一個(gè)碳原子的多環(huán)烷烴集合環(huán)烷烴-環(huán)與環(huán)之間以單鍵直接相連的多環(huán)烷烴環(huán)烷烴Organic ChemistryOrganic ChemistryXiamen Univers

31、ityXiamen University 環(huán)烷烴的異構(gòu)和命名1. 單環(huán)烷烴2. 橋環(huán)烴3. 螺環(huán)烴Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University1. 單環(huán)烷烴分類小環(huán)化合物 C3C4普通環(huán)化合物 C5C7中環(huán)化合物 C8C11大環(huán)化合物 C12Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University異構(gòu)碳架異構(gòu)、順反異構(gòu)、旋光異構(gòu)、構(gòu)象異構(gòu)順反異構(gòu)：由于成環(huán)原子之間的單鍵不能自由旋轉(zhuǎn)而引起。兩個(gè)取代基在環(huán)平面同側(cè)為順式，不同側(cè)

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

33、yXiamen University2. 橋環(huán)烴的命名1. 確定母體烴2. 確定環(huán)數(shù)3. 選主環(huán)4. 選主橋5. 編號(hào)6. 確定方括號(hào)內(nèi)數(shù)字7. 寫出完整的名稱環(huán)數(shù)方括號(hào)內(nèi)數(shù)字母體烴名Organic ChemistryOrganic ChemistryXiamen UniversityXiamen UniversityCH2CH3123456CH3 7 CH34351 267CH2CH37,7-二甲基-2-乙基二環(huán)2.2.1庚烷2-Ethyl-7,7-dimethylbicyclo2.2.1heptane8三環(huán)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(huán)烴的命名1. 確定母體烴2. 確定螺數(shù)3. 編號(hào)4. 選主橋5. 編號(hào)6. 寫出完整的名稱螺數(shù)方括號(hào)內(nèi)數(shù)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(huán)烷烴的物理性質(zhì)自學(xué)Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University 環(huán)烷烴的化學(xué)性質(zhì)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(xué)說張力學(xué)說的根底張力學(xué)說的內(nèi)容張力學(xué)說的缺陷Organic ChemistryOrganic ChemistryXiamen UniversityXiamen University 環(huán)烷烴的構(gòu)象Xiamen UniversityXiamen UniversityOrganic ChemistryOrganic Chemistry1. 環(huán)己烷的構(gòu)象椅式構(gòu)象(chair form)2.51 Aequatorial12a

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