به نام خدا شیمی آلی 1

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1 به نام خدا شیمی آلی 1

1. McMurry, Organic Chemistry, 7th ed., Brooks/Cole, Monterey CA, 2008. (8 th ed.) 2. Morrison and Boyd, Organic Chemistry, 6th ed.

Vollhardt and Schore, Organic Chemistry, 4th ed.,w.h. Freeman, New York, 2002. 5.

2 1. McMurry, Organic Chemistry, 7th ed., Brooks/Cole, Monterey CA, (8 th ed.) 2. Morrison and Boyd, Organic Chemistry, 6th ed., Benjamin Cummings, CA, Carey, Organic Chemistry, 6th ed., McGraw-Hill, NY, Vollhardt and Schore, Organic Chemistry, 4th ed.,w.h. Freeman, New York, Streitwieser, Heathcock, and Kosower, Introduction to Organic Chemistry, 4th ed.; Prentice-Hall, Saddle River, NJ, Clayden, Greeves, Warren and Wothers, Organic Chemistry, Oxford University Press, New York, 2001.

3 کوئیز: 15 نمره نظم و ترتیب و حضور و غیاب: 25 نمره امتحان نیم ترم: 60 نمره امتحان آخر ترم: 100 نمره

4 شیمی آلی جلد اول- ویرایش هفتم ترجمه: دکترعیسی یاوری نشر نوپردازان - تهران 1390

5 سخن نویسنده کتاب با دانشجویان بی درنگ به خواندن کتاب نپردازید: 1- نگاهی گذرا به مطالب هر فصل 2- آشنایی اولیه با موضوع هر فصل توسط خواندن مقدمه آن 3- مطالعه چکیده پایان فصل 4- هر فصل چندبار مرور و خوانده شود - بار اول: مرور سریع و مشخص کردن نکته های مهم و دشوار متن - سپس مطالعه ژرف تر موضوعات فصل

6 مسئله ها را حل کنید: 1- تنها راه یادگیری شیمی آلی: حل کردن مسائل شیمی آلی 2 -حل تمرین های متن کتاب: آشنا شدن با روش کار و امکان خودآزمایی 3- حل تمرین های پایان فصل: آشنایی با چالش های جدید و امکان تمرین بیشتر 4- حل تمرین های "شیمی تجسمی": آشنایی با دنیای واقعی مولکول ها پاسخ کوتاه مسائل: در پیوست کتاب پاسخ و شرح کامل: در کتاب راهنما - - 6

Santa Cruz, Cornell University Alma mater Harvard University A.B.

8 McMurry, John Edward (Professor Emeritus) Born July 27, 1942 (age 75) New York City, United States Nationality Institutions American University of California, Santa Cruz, Cornell University Alma mater Harvard University A.B Columbia University Ph.D Doctoral advisor Known for Gilbert Stork McMurry reaction

9 book Fundamentals of Organic Chemistry, 7th Edition 2011 Organic Chemistry: With Biological Applications, 2nd Edition 2011 Chemistry, 6th Edition. Pearson Fundamentals of General, Organic, and Biological Chemistry, 6th Edition. Pearson General Chemistry: Atoms First. Pearson The Organic Chemistry of Biological Pathways. Roberts & Company Publishing Organic Chemistry, 8th Edition Cengage Learning.

Professor Issa Yavari Tarbiat Modares University Issa Yavari was born in 1948 in Kermanshah, Iran and studied chemistry at Pars College, Tehran, where he obtained B.Sc. and M. Sc. He received his Ph.

10 Professor Issa Yavari Tarbiat Modares University Issa Yavari was born in 1948 in Kermanshah, Iran and studied chemistry at Pars College, Tehran, where he obtained B.Sc. and M. Sc. He received his Ph.D. in the area of Strain-Energy Calculations and Dynamic NMR Studies of Medium Rings in 1977 from the University of California, Los Angeles. After work as Postdoctoral Fellow in the California Institute of Technology in the field of Application of 15 N NMR in Proton-Exchange Studies, he joined the faculty at the University of Mazandaran, Iran, in In 1984 he moved to the Tarbiat Modares University in Tehran. His research has focused on Quantum-Mechanics Calculations, Multicomponent Reactions, and Organic Chemistry of Phosphorus and Sulfur.

11 1 Structure and Bonding 2 Polar Covalent Bonds; Acids and Bases 3 Organic Compounds: Alkanes and Their Stereochemistry 4 Organic Compounds: Cycloalkanes and Their Stereochemistry 5 An Overview of Organic Reactions 6 Alkenes: Structure and Reactivity 7 Alkenes: Reactions and Synthesis 8 Alkynes: An Introduction to Organic Synthesis 9 Stereochemistry 10 Organohalides 11 Reactions of Alkyl Halides: Nucleophilic Substitutions and Eliminations 11

12 1 ساختار و پیوند )Structure and Bonding( Based on McMurry s Organic Chemistry, 7 th edition

13 شیمی آلی چیست جانداران زنده از مواد شیمیایی آلی تشکیل شده اند پروتئین هایی که مو پوست و... می سازند DNA میراث ژنی را کنترل می کند غذاها و داروها و... ساختاری مشابه ترکیبات زیر را دارند: داروي ضد التهاب غير استروئيدي 13

14 Many of the materials we use today are made by chemical synthesis. Most of the new compounds made today are organic.

منشا شیمی آلی بنیاد شیمی آلی به اواسط سده هیجدهم بازمی گردد. استخراج و خالص سازی ترکیبات به دست آمده از گیاهان و جانوران اغلب سخت بود. o o o ترکیبات اغلب به سادگی دستخوش تجزیه می شدند.

15 منشا شیمی آلی بنیاد شیمی آلی به اواسط سده هیجدهم بازمی گردد. استخراج و خالص سازی ترکیبات به دست آمده از گیاهان و جانوران اغلب سخت بود. o o o ترکیبات اغلب به سادگی دستخوش تجزیه می شدند. Torben Bergman سوئدی نخستین کسی بود که در 1770 به تفاوت بین مواد آلی و معدنی اشاره کرد. o Torbern Olaf Bergman از آنجاکه ترکیبات آلی از منابع زیستی بدست می آمدند تصور براین بود که این ترکیبات باید شامل یک نیروی حیاتی force vital باشند. o 15

شورول Chevreul در سال 1816 برخالف این مورد صابون را از چربی حیوانی و قلیا تهیه

16 براساس نظریه «نیروی حیاتی» تصور می شد که ترکیبات آلی برخالف ترکیبات معدنی قابل تهیه در آزمایشگاه نیستند. شورول Chevreul در سال 1816 برخالف این مورد صابون را از چربی حیوانی و قلیا تهیه کرد. Michel Eugène Chevreul وهلر Wohler درسال 1828 روشی را برای تبدیل نمک معدنی آمونیم سیانات به ماده آلی اوره پیدا کرد. Friedrich Wöhler 16

17 شیمی آلی مطالعه ترکیبات کربن است. چرا کربن ویژه است %99 از 30 میلیون ترکیب شیمیایی کربن دارند. CAS جواب بسیاری از این پرسش ها را می توان در جدول تناوبی مشاهده نمود. کربن عنصری از گروه 4A است که می تواند چهار الکترون ظرفیتی را به اشتراک گذاشته و 4 پیوند کوواالنسی تشکیل. دهد 17

18 18

19 چرا این فصل مرور برخی ایده ها از درس شیمی عمومی: اتمها پیوندها و وضعیت هندسی مولکولها 19

20 ساختار اتمی 1.1 Atomic Structure 20

21 WHAT IS AN ATOM? o The smallest unit of an element. o Consists of a central nucleus surrounded by one or more electrons.

22 WHAT IS THE NUCLEUS? o The central part of an atom. o Composed of protons and neutrons. o Contains most of an atom's mass.

23 WHAT IS A PROTON? o Positively charged particle. o Found within an atomic nucleus.

24 WHAT IS A NEUTRON? o Uncharged particle. o Found within an atomic nucleus.

25 WHAT IS AN ELECTRON? o Negatively charged particle. o Located in shells that surround an atom's nucleus.

3,000,000 Positively charged nucleus (very

26 3,000,000 Positively charged nucleus (very dense, protons and neutrons) and small (10-15 m) Negatively charged electrons are in a cloud (10-10 m) around nucleus Diameter(atom) is about m (200 picometers (pm)) [the unit angstrom (Å) is m = 100 pm] 26

)عدد اتمی( Atomic Number )عدد جرمی( and Atomic Mass The atomic number ) اتمی )عدد (Z) is The number of protons in the atom's nucleus The mass number ) جرمی )عدد (A) is the number of protons plus

27 )عدد اتمی( Atomic Number )عدد جرمی( and Atomic Mass The atomic number ) اتمی )عدد (Z) is The number of protons in the atom's nucleus The mass number ) جرمی )عدد (A) is the number of protons plus neutrons All the atoms of a given element have the same atomic number: Isotopes are atoms of the same element that have different numbers of neutrons and therefore different mass numbers The atomic mass ) اتمی )جرم (atomic weight) of an element is the weighted average mass in atomic mass units (amu) of an element s naturally occurring isotopes 27

)گاهشمار( Timeline 1803- مدل دالتون: اتم ها ذرات کروی تو پر هستند.

1911- مدل راترفورد: مدل اتمی پیشنهادی وی مدل اتم هسته دار نام دارد.

28 )گاهشمار( Timeline مدل دالتون: اتم ها ذرات کروی تو پر هستند مدل تامسون )مدل کیک کشمشی(: اتم خمیری از بار مثبت است که الکترون ها مانند کشمش در آن قرار دارند مدل راترفورد: مدل اتمی پیشنهادی وی مدل اتم هسته دار نام دارد مدل بور )مدل منظومه شمسی(: الکترون ها در مسیر های دایره ای به نام مدار قرار دارند و با انرژی معینی به دور هسته می چرخند مدل ابر الکترونی: نشان دهنده احتمال وجود الکترونها مدل مکانیک کوانتمی : مدلی ریاضی که رفتار الکترونها و انرژی الکترونها را در مناطق مختلف اطراف هسته بیان می کند.

29 1.2 Atomic Structure: Orbitals (wave equation) مکانیک کوانتمی :Quantum mechanics انرژی و احتمال وجود الکترون را توسط یک معادله موج بیان می کند. تابع موج function) (Wave جواب معادله موج است هر تابع موج عبارت از یک اوربیتال y است نمودار y 2 جایی است که بیشترین احتمال پیداکردن یک الکترون آن را در محدوده بدست می دهد. ابر الکترونی دارای مرز خاصی نیست اما بیشترین احتمال آنرا در آن محدوده نشان می دهد. 29

Shapes of Atomic Orbitals for Electrons Four different kinds of orbitals Denoted s, p, d, and f s and p orbitals most important in organic and biological

30 Shapes of Atomic Orbitals for Electrons Four different kinds of orbitals Denoted s, p, d, and f s and p orbitals most important in organic and biological chemistry s orbitals: spherical, nucleus at center p orbitals: dumbbell-shaped, nucleus at middle d orbitals: elongated dumbbell-shaped, nucleus at center 30

31 Orbitals and Shells part 1 Orbitals are grouped in shells of increasing size and energy Different shells contain different numbers and kinds of orbitals Each orbital can be occupied by two electrons 31

32 Orbitals and Shells part 2 First shell contains one s orbital, denoted 1s, holds only two electrons Second shell contains one s orbital (2s) and three p orbitals (2p), eight electrons Third shell contains an s orbital (3s), three p orbitals (3p), and five d orbitals (3d), 18 electrons 32

33 p-orbitals In each shell there are three perpendicular p orbitals, p x, p y, and p z, of equal energy Lobes of a p orbital are separated by region of )گره( zero electron density, a node 33

34 1.3 Atomic Structure: Electron Configurations )آرایش الکترونی حالت پایه( Ground-state electron configuration (lowest energy arrangement) of an atom lists orbitals occupied by its electrons. Rules: 1. Lowest-energy orbitals fill first: 1s 2s 2p 3s 3p 4s 3d (Aufbau ( build-up» کردن»بنا ) principle) 2. Electrons act as if they were spinning around an axis. Electron spin can have only two orientations, up and down. Only two electrons can occupy an orbital, and they must be of opposite spin (Pauli exclusion principle طرد پائولی (اصل to have unique wave equations 3. If two or more empty orbitals of equal energy are available, electrons occupy each with spins parallel until all orbitals have ). قاعده هوند one electron (Hund's rule 34

1.4 Development of Chemical Bonding Theory Kekulé

always has four bonds Archibald Scott Couper

van't Hoff and Le Bel proposed that the four bonds

surround carbon as corners of a tetrahedron Joseph

35 1.4 Development of Chemical Bonding Theory Kekulé and Couper independently observed that carbon always has four bonds Archibald Scott Couper ( ) Friedrich August Kekulé ( ) van't Hoff and Le Bel proposed that the four bonds of carbon have specific spatial directions Atoms surround carbon as corners of a tetrahedron Joseph Achille Le Bel ( ) Jacobus Henricus van 't Hoff, Jr. ( ) 35

36 Atoms form bonds because the compound that results is more stable than the separate atoms Ionic bonds in salts form as a result of electron transfers Organic compounds have covalent bonds from sharing electrons (G. N. Lewis, 1916) Gilbert Newton Lewis ( ) 36

37 Lewis structures (electron dot) show valence electrons of an atom as dots Hydrogen has one dot, representing its 1s electron Carbon has four dots (2s 2 2p 2 ) Kekule structures (line-bond structures) have a line drawn between two atoms indicating a 2 electron covalent bond. Stable molecule results at completed shell, octet (eight dots) for main-group atoms (two for hydrogen) 37

38 Atoms with one, two, or three valence electrons form one, two, or three bonds. Atoms with four or more valence electrons form as many bonds as they need electrons to fill the s and p levels of their valence shells to reach a stable octet. Carbon has four valence electrons (2s 2 2p 2 ), forming four bonds (CH 4 ). 38

39 Nitrogen has five valence electrons (2s 2 2p 3 ) but forms only three bonds (NH 3 ). Oxygen has six valence electrons (2s 2 2p 4 ) but forms two bonds (H 2 O) 39

40 Non-bonding electrons Valence electrons not used in bonding are called nonbonding electrons, or lone-pair electrons Nitrogen atom in ammonia (NH 3 ) Shares six valence electrons in three covalent bonds and remaining two valence electrons are nonbonding lone pair 40

ماهیت پیوندهای شیمیایی: نظریه پیوند شیمیایی 5-1 یک پیوند کوواالنسی هنگامی تشکیل می شود که دو اتم چنان به یک اوربیتال تک الکترونی یکی از آنها با اوربیتال تک الکترونی نماید.

41 ماهیت پیوندهای شیمیایی: نظریه پیوند شیمیایی 5-1 یک پیوند کوواالنسی هنگامی تشکیل می شود که دو اتم چنان به یک اوربیتال تک الکترونی یکی از آنها با اوربیتال تک الکترونی نماید. هم اتم نزدیک شوند که دیگر همپوشانی کوواالنسی پیوند بیان برای مدل دو دارد: وجود ( نظریه پیوند ظرفیتی( Valence bond theory ( نظریه اوربیتال مولکولی ) theory Molecular orbital نظریه پیوند ظرفیتی Valence bond theory الکترون ها به صورت جفت وسیله هسته هردو اتم جذب H H پیوند پیوند شود H H همپوشانی از تقارن شده در اوربیتال می شوند دو استوانه اوربیتال دارد ای 1sتک پیوند و های الکترونی سیگما همپوشاننده هیدروژن قرار تشکیل می sigma (s) bond. 41 گیرند می شود نامیده به و می

42 Bond Energy Reaction 2 H H 2 releases 436 kj/mol Product has 436 kj/mol less energy than two atoms: H H has bond strength of 436 kj/mol or 104 kcal/mol). (1 kj = kcal; 1 kcal = kj) 42

43 Bond Length دنویپ لوط ترابع زا هلصاف هنیهب نیب هتسه تساه هک رجنم هب نیرتشیب یرادیاپ دوش یم رگا هتسه اه هب مه رایسب کیدزن دنشاب هب لیلد تبثم ندوب راب ره ود رگیدکی ار عفد یم دننک رگا زا مه رود دنشاب رداق هب کارتشا یاهنورتکلا یتیفرظ دنهاوخن دوب 43

1.6 sp 3 Orbitals and the Structure of Methane

The predicted H-P-H bond angle is 90 o, and the

44 1.6 sp 3 Orbitals and the Structure of Methane Using the Valence-Bond Method to Describe a Molecular Structure Describe the phosphine molecule, PH 3 by the valence-bond method. The predicted H-P-H bond angle is 90 o, and the experimentally measured bond angles are 93 o to 94 o. These are in good agreement. 44

45 Methane - CH 4 bond angles = bond distances = 110 pm Applying simple VB theory results in the following prediction for methane bonding: According to this model, the C is bonded to only two H-atoms with an H-C-H bond of?.. This is NOT what is observed for methane! 45

46 هیبرید شدن Hybridisation 46

47 Hybridisation C 1s 2s 2p z y 1s orbital z y 2s orbital z y z y z y 2p x orbital 2p y orbital 2p z orbital

48 Increasing energy Methane 2p hybridised orbitals 2s SP 3 orbitals

orbitals combine to form four equivalent, unsymmetrical, tetrahedral

50 Carbon has 4 valence electrons (2s 2 2p 2 ) In CH 4, all C H bonds are identical (tetrahedral) sp 3 hybrid orbitals: s orbital and three p orbitals combine to form four equivalent, unsymmetrical, tetrahedral orbitals (sppp = sp 3 ), Pauling (1931) Linus Carl Pauling ( ) 50

51 The Structure of Methane sp3 orbitals on C overlap with 1s orbitals on 4 H atoms to form four identical C-H bonds Each C H bond has a strength of 436 kj/mol and length of 109 pm Bond angle: each H C H is 109.5, the tetrahedral angle. 51

1.7 sp 3 Orbitals and the Structure of Ethane Two C s bond to each other by s overlap of an sp 3 orbital from each Three sp 3 orbitals on each C overlap with H 1s

52 1.7 sp 3 Orbitals and the Structure of Ethane Two C s bond to each other by s overlap of an sp 3 orbital from each Three sp 3 orbitals on each C overlap with H 1s orbitals to form six C H bonds C H bond strength in ethane 423 kj/mol C C bond is 154 pm long and strength is 376 kj/mol All bond angles of ethane are tetrahedral 52

53 Ethane: CH 3 -CH 3

54 Increasing energy Ethylene single unhybridised 2p orbital 2p hybridised orbitals 2s SP 2 orbitals

55 1.8 sp 2 Orbitals and the Structure of Ethylene sp 2 hybrid orbitals: 2s orbital combines with two 2p orbitals, giving 3 orbitals (spp = sp 2 ). This results in a double bond. sp 2 orbitals are in a plane with120 angles Remaining p orbital is perpendicular to the plane 55

57 Bonds From sp 2 Hybrid Orbitals Two sp 2 -hybridized orbitals overlap to form a s bond p orbitals overlap side-to-side to formation a pi ( ) bond sp 2 sp 2 s bond and 2p 2p bond result in sharing four electrons and formation of C-C double bond Electrons in the s bond are centered between nuclei Electrons in the bond occupy regions are on either side of a line between nuclei 57

58 Structure of Ethylene H atoms form s bonds with four sp 2 orbitals H C H and H C C bond angles of about 120 C C double bond in ethylene shorter and stronger than single bond in ethane Ethylene C=C bond length 134 pm (C C 154 pm) 58

1.9 sp Orbitals and the Structure of Acetylene C-C a triple bond sharing six electrons Carbon 2s orbital hybridizes with a single p orbital giving two

59 1.9 sp Orbitals and the Structure of Acetylene C-C a triple bond sharing six electrons Carbon 2s orbital hybridizes with a single p orbital giving two sp hybrids two p orbitals remain unchanged sp orbitals are linear, 180 apart on x-axis Two p orbitals are perpendicular on the y-axis and the z-axis 59

60 Acetylene C 2 H 2 One s-bond & two -bonds

62 Orbitals of Acetylene Two sp hybrid orbitals from each C form sp sp s bond p z orbitals from each C form a p z p z bond by sideways overlap and p y orbitals overlap similarly 62

63 Bonding in Acetylene Sharing of six electrons forms C C Two sp orbitals form s bonds with hydrogens 63

64 Double and Triple Bonds

66 66

67 1.10 Hybridization of Nitrogen and Oxygen Elements other than C can have hybridized orbitals H N H bond angle in ammonia (NH 3 ) C-N-H bond angle is N s orbitals (sppp) hybridize to form four sp 3 orbitals One sp 3 orbital is occupied by two nonbonding electrons, and three sp 3 orbitals have one electron each, forming bonds to H and CH 3. 67

68 1.11 Molecular Orbital Theory A molecular orbital (MO): where electrons are most likely to be found (specific energy and general shape) in a molecule Additive combination ترکیب جمعی (bonding) MO is lower in energy Subtractive combination ترکیب تفریقی (antibonding) MO is higher energy 68

69 Molecular Orbitals in Ethylene The bonding MO is from combining p orbital lobes with the same algebraic sign The antibonding MO is from combining lobes with opposite signs Only bonding MO is occupied 69

70 1.12 Drawing Structures Drawing every bond in organic molecule can become tedious. Several shorthand methods have been developed to write structures. Condensed structures don t have C-H or C-C single bonds shown. They are understood. e.g. )ساختارهای متراکم( 70

71 3 General Rules: 1) Carbon atoms aren t usually shown. Instead a carbon atom is assumed to be at each intersection of two lines (bonds) and at the end of each line. 1( اتم های کربن معموال نشان داده نمی شوند 2) Hydrogen atoms bonded to carbon aren t shown. اتم های هیدروژن متصل به کربن نشان داده نمی شوند 3) Atoms other than carbon and hydrogen are shown (See table 1.3). 3( سایر اتم ها نشان داده می شوند )2 71

72 72

73 Journal of Chemical Education, 1988, 65,

به نام خدا. Organic Chemistry 1. Dr Morteza Mehrdad University of Guilan, Department of Chemistry, Rasht, Iran

به نام خدا. Organic Chemistry 1. Dr Morteza Mehrdad University of Guilan, Department of Chemistry, Rasht, Iran به نام خدا Organic Chemistry 1 Dr Morteza Mehrdad University of Guilan, Department of Chemistry, Rasht, Iran m-mehrdad@guilan.ac.ir 1. McMurry, Organic Chemistry, 7th ed., Brooks/Cole, Monterey CA, 2008.