1. Principals of Organic Chemistry مبادئ الكيمياء العضوية

2. معلومات عن أستاذة المقرر
الاسم : د. سوزان عبدالرحمن خياط
أستاذ الكيمياء العضوية المشارك
قسم الكيمياء
كلية العلوم (فرع الفيصلية) – جامعة الملك عبدالعزيز
غرفة رقم 314A الدور الثاني – 109 C الدور الأرضي
البريد الإلكتروني
الموقع الإلكتروني

3. Principals of Organic Chemistry مبادئ الكيمياء العضوية11
Course No.
رمز ورقم المقرر
Course Title
اسم المقرر
No. of Units
عدد الوحدات
Pre-requisites
المتطلب السابق
Th.
النظري
Pr.
العملي
Credit
المعتمدة
CHEM 230
Principals of Organic Chemistry 
مبادئ الكيمياء العضوية 3 4
CHEM 110
أهداف المقرر:
يهدف المقرر إلى تعميق فهم الطالبة عن الترابط الكيميائي، تصنيف المركبات العضوية وتسميتها، والتشكل بأنواعه في المركبات العضوية، ودراسة التفاعلات العضوية الهامه لأصناف المركبات العضوية المختلفة.
المحتوى العلمي للمقرر:
دراسة الربط الكيميائي في المركبات العضوية من خلال نظرية التهجين - تقسيم المركبات العضوية حسب المجموعة الوظيفية - تسمية المركبات العضوية - التشكل - التفاعلات الكيميائية - المركبات الحلقية غير المتجانسة – السكريات - الأحماض الأمينية والبروتينات - التربينات -تطبيقات المركبات العضوية في الطب والزراعة والتغذية والصناعة
chapter 1

4. توزيع الدرجات 10 أعمال سنة 15 اختبار دوري أول اختبار دوري ثاني 20
اختبار عملي 40
اختبار نهائي
100 درجة
المجموع النهائي
chapter 1

5. Main Text Book الكتاب الرئيسي المقرر
“Organic Chemistry”, T. W. ,Graham Solomons & Caring B. Fryhle; 8th ed, 2007.
chapter 1

6. Chapter 1B Carbon Compounds and Chemical Bonds

7. Organic compounds are compounds that could be obtained from living organisms.
Inorganic compounds are compounds that came from nonliving sources.

8. Introduction of Organic Chemistry
The chemistry of the compounds of carbon.
The human body is largely composed of organic compounds.
Organic chemistry plays a central role in medicine, bioengineering etc.

9. Common Elements in Organic Compounds

10. The structure of atom Simplified structure of an atom
structure of carbon atom

11. Chemical Bonds: The Octet Rule
Atoms form bonds to produce the electron configuration of a noble gas (because the electronic configuration of noble gases is particularly stable).
For most atoms of interest this means achieving a valence shell configuration of 8 electrons corresponding to that of the nearest noble gas.
Atoms close to helium achieve a valence shell configuration of 2 electrons.
Atoms can form either ionic or covalent bonds to satisfy the octet rule.
G. N. Lewis

12. Kinds of chemical bonds: Ionic bonds Covalent bonds Metallic bonds
A chemical bond is a force of attraction that holds two atoms together to fill its electron shells with 8 electrons (octet rule).
Kinds of chemical bonds:
Ionic bonds
Covalent bonds
Metallic bonds
chapter 1

13. IONIC BOND bond formed between two ions by the transfer of electrons

14. The Covalent Bond
A covalent bond is a chemical bond formed between (nonmetal + nonmetal) or (metalloide + nonmetal) in which two or more electrons are shared by two atoms.
chapter 1

15. The Covalent Bond
Covalent bonds occur between atoms of similar electronegativity (close to each other in the periodic table)
Atoms achieve octets by sharing of valence electrons
Molecules result from this covalent bonding
Valence electrons can be indicated by dots (electron-dot formula or Lewis structures) but t time-consuming
The usual way to indicate the two electrons in a bond is to use a line (one line = two electrons)
chapter 1

16. Oxygen Molecule (O2) The Covalent Bond Oxygen Atom Oxygen Atom
chapter 1

17. P+1 P+1 The Covalent Bond when two atoms share a pair of electrons.
chapter 1

18. It’s like both atoms have a filled orbital.
The Covalent Bond
when two atoms share a pair of electrons.
P+1
P+1
It’s like both atoms have a filled orbital.
chapter 1

19. The Covalent Bond
The sharing of a pair of electrons between 2 atoms.
(or even 2 or 3 pairs of electrons). H2

20. The Covalent Bond
The sharing of a pair of electrons between 2 atoms.
Cl2

21. Non polar covalent Bond
Covalent Bonds
Non polar covalent Bond
Atoms achieve octets by sharing of valence electrons
Molecules result from this covalent bonding
Valence electrons can be indicated by dots (electron-dot formula or Lewis structures) but this is time-consuming
The usual way to indicate the two electrons in a bond is to use a line (one line = two electrons)
Chapter 1

22. 2-Polar covalent bond or polar bond
is a covalent bond with greater electron density around one of the two atoms H F
electron rich
region
electron poor
region
e- poor
e- rich F H d+ d-
9.5

23. 3- The Metallic Bond
Metallic Bond is a bond found in metals; holds metal atoms together very strongly.
Formed between atoms of metallic elements.
Electron clouds around atoms.
Good conductors at all states, very high melting points
Examples; Na, Fe, Al, Au, Co, Cu

24. Orbital: a region in space where the probability of finding an electron is large
Atomic Orbitals (AOs): The region of space where one or two electrons of an isolated atom are likely to be found.
Molecular Orbitals (MOs) :The region of space where one or two electrons of a molecule are likely to be found.
chapter 1

25. Bonding Molecular Orbitals (Ymolec)
AOs combine by addition (the AOs of the same phase sign overlap)
The value of Y2 (electron probability density) in the region between the two nuclei increases
The two electrons between the nuclei serve to attract the nuclei towards each other
This is the ground state (lowest energy state) of the MO
chapter 1

26. Molecular Orbital of Hydrogen
bonding orbital
antibonding orbital
chapter 1

27. The energy of electrons in the bonding orbitals is substantially less than the energy of electrons in the individual atoms
The energy of electrons in the antibonding orbitals is substantially more
In the ground state of the hydrogen molecule electrons occupy the lower energy bonding orbital only
chapter 1

28. Bonding Molecular Orbital
The overlapping of two hydrogen 1s atomic orbitals
Ψ+ = Ø1 + Ø2
bonding orbital Ø2
atomic orbital Ø1 1s
The overlapping of two hydrogen 1s waves
chapter 1

29. Antibonding molecular orbital (Y *molec)
Formed by interaction of AOs with opposite phase signs
Electrons in the antibonding orbital avoid the region between the two nuclei
Repulsive forces between the nuclei predominate and electrons in antibonding orbitals make nuclei fly apart
chapter 1

30. Antibonding Molecular Orbital
The overlapping of two hydrogen 1s atomic orbitals Ø2
atomic orbital Ø1 1s
Ψ- = Ø1 - Ø2
antibonding orbital
The overlapping of two hydrogen 1s waves
node
chapter 1

31. Formation of (sigma σ) bondH2
HCl
Cl2
chapter 1

32. a) Sigma bond formation by s – s overlap
Diagram of sigma bond formation by s – s overlap
chapter 1

33. b) Sigma bond formation by s – p overlap
Diagram of sigma bond formation by s – p overlap
chapter 1

34. Diagram of sigma bond formation by p – p overlap
c) Sigma bond formation by p – p overlap
Energy
Diagram of sigma bond formation by p – p overlap
chapter 1

35. Formation of (pi π) bond
chapter 1

36. Structural Theory Central Premises
Valency: atoms in organic compounds form a fixed number of bonds.
Carbon can form one or more bonds to other carbons.

37. The Structure of Methane and Ethane: sp3 Hybridization
The structure of methane with its four identical tetrahedral bonds cannot be adequately explained using the electronic configuration of carbon
Hybridization of the valence orbitals (2s and 2p) provides four new identical orbitals which can be used for the bonding in methane
Orbital hybridization is a mathematical combination of the 2s and 2p wave functions to obtain wave functions for the new orbitals
chapter 1

38. Each new molecular orbital can accommodate 2 electrons
When one 2s orbital and three 2p orbitals are hybridized four new and identical sp3 orbitals are obtained
When four orbitals are hybridized, four orbitals must result
Each new orbital has one part s character and 3 parts p character
The four identical orbitals are oriented in a tetrahedral arrangements
The antibonding orbitals are not derived in the following diagram
The four sp3 orbitals are then combined with the 1s orbitals of four hydrogens to give the molecular orbitals of methane
Each new molecular orbital can accommodate 2 electrons
chapter 1

39. sp3 hybridization in Methane CH4
excitation
becomes
Ground state
excited state
chapter 1

40. chapter 1

41. A variety of representations of methane show its tetrahedral nature and electron distribution
a. calculated electron density surface b. ball-and-stick model c. a typical 3-dimensional drawing
chapter 1

42. Molecule geometry of CH4
4 sp3 hybrid orbitals
10.4

43. Ethane (C2H6)
The carbon-carbon bond is made from overlap of two sp3 orbitals to form a s bond
The molecule is approximately tetrahedral around each carbon
chapter 1

44. Generally there is relatively free rotation about s bonds
The representations of ethane show the tetrahedral arrangement around each carbon
a. calculated electron density surface b. ball-and-stick model c. typical 3-dimensional drawing
Generally there is relatively free rotation about s bonds
Very little energy (13-26 kcal/mol) is required to rotate around the carbon-carbon bond of ethane
chapter 1

45. Examples of Sigma Bond Formation

46. The Structure of Ethene (Ethylene) : sp2 Hybridization
Ethene (C2H2) contains a carbon-carbon double bond and is in the class of organic compounds called alkenes
Another example of the alkenes is propene
The geometry around each carbon is called trigonal planar
All atoms directly connected to each carbon are in a plane
The bonds point towards the corners of a regular triangle
The bond angle are approximately 120o
chapter 1

47. The C—C s Bond in Ethane
In-phase overlap of half-filled sp3 hybrid orbital of one carbon with half-filled sp3 hybrid orbital of another. Overlap is along internuclear axis to give a s bond.

48. The C—C s Bond in Ethane
In-phase overlap of half-filled sp3 hybrid orbital of one carbon with half-filled sp3 hybrid orbital of another. Overlap is along internuclear axis to give a s bond.

49. hybrid orbitals – sp, sp2, or sp3

50. hybrid orbitals – sp, sp2, or sp3

52. formation of s bond

53. The sp2 orbitals are arranged in a trigonal planar arrangement
There are three s bonds around each carbon of ethene and these are formed by using sp2 hybridized orbitals
The three sp2 hybridized orbitals come from mixing one s and two p orbitals
One p orbital is left unhybridized
The sp2 orbitals are arranged in a trigonal planar arrangement
The p orbital is perpendicular (orthoganol) to the plane
chapter 1

54. Overlap of sp2 orbitals in ethylene results in formation of a s framework
One sp2 orbital on each carbon overlaps to form a carbon-carbon s bond; the remaining sp2 orbitals form bonds to hydrogen
The leftover p orbitals on each carbon overlap to form a bonding p bond between the two carbons
A p bond results from overlap of p orbitals above and below the plane of the s bond
It has a nodal plane passing through the two bonded nuclei and between the two lobes of the p molecular orbital
chapter 1

56. The bonding p orbital is lower in energy than the antibonding orbital
The bonding p orbital results from overlap of p orbital lobes of the same sign
The antibonding p* orbital results from overlap of p orbital lobes of opposite sign
The antibonding orbital has one node connecting the two nuclei and another node between the two carbons
The bonding p orbital is lower in energy than the antibonding orbital
In the ground state two spin paired electrons are in the bonding orbital
The antibonding p*orbital can be occupied if an electron becomes promoted from a lower level ( e.g. by absorption of light)
chapter 1

57. The s orbital is lower in energy than the p orbital
The ground state electronic configuration of ethene is shown
chapter 1

58. remaining p orbitals from sp or sp2
s bond
remaining p orbitals from sp or sp2

61. p bond hinders rotation about the carbon-to-carbon bond
Planar molecule (each carbon is trigonal planar) with p cloud above and below the plane
formation of p bond

62. Restricted Rotation and the Double Bond
There is a large energy barrier to rotation (about 264 kJ/mol) around the double bond
This corresponds to the strength of a p bond
The rotational barrier of a carbon-carbon single bond is kJ/mol
This rotational barrier results because the p orbitals must be well aligned for maximum overlap and formation of the p bond
Rotation of the p orbitals 90o totally breaks the p bond
chapter 1

63. The Structure of Ethyne (Acetylene): sp Hybridization
Ethyne (acetylene) is a member of a group of compounds called alkynes which all have carbon-carbon triple bonds
Propyne is another typical alkyne
The arrangement of atoms around each carbon is linear with bond angles 180o
chapter 1

64. The carbon in ethyne is sp hybridized
One s and one p orbital are mixed to form two sp orbitals
Two p orbitals are left unhybridized
The two sp orbitals are oriented 180o relative to each other around the carbon nucleus
The two p orbitals are perpendicular to the axis that passes through the center of the sp orbitals
chapter 1

65. In ethyne the sp orbitals on the two carbons overlap to form a s bond
The remaining sp orbitals overlap with hydrogen 1s orbitals
The p orbitals on each carbon overlap to form two p bonds
The triple bond consists of one s and two p bonds
chapter 1

66. Depictions of ethyne show that the electron density around the carbon-carbon bond has circular symmetry
Even if rotation around the carbon-carbon bond occurred, a different compound would not result
chapter 1

67. Bond Lengths of Ethyne, Ethene and Ethane
The carbon-carbon bond length is shorter as more bonds hold the carbons together
With more electron density between the carbons, there is more “glue” to hold the nuclei of the carbons together
The carbon-hydrogen bond lengths also get shorter with more s character of the bond
2s orbitals are held more closely to the nucleus than 2p orbitals
A hybridized orbital with more percent s character is held more closely to the nucleus than an orbital with less s character
The sp orbital of ethyne has 50% s character and its C-H bond is shorter
The sp3 orbital of ethane has only 25% s character and its C-H bond is longer
chapter 1

68. Summary of Concepts from Quantum Mechanics
Atomic Orbital(AO): region in space around a nucleus where there is a high probability of finding an electron
Molecular Orbital (MO): results from overlap of atomic orbitals
Bonding Orbitals: when AOs of same sign overlap
Antibonding Orbitals: when AOs of opposite sign overlap
The energy of electrons in a bonding orbital is less than the energy of the individual atoms
The energy of electrons in an antibonding orbitals is more
chapter 1

69. The number of molecular orbitals formed equals the number of the atomic orbitals used
Hybridized orbitals are obtained by mixing the wave functions of different types of orbitals
Four sp3 orbitals are obtained from mixing one s and three p orbitals
The geometry of the four orbitals is tetrahedral
This is the hybridization used in the carbon of methane
Three sp2 orbitals are obtained from mixing one s and two p orbitals
The geometry of the three orbitals is trigonal planar
The left over p orbital is used to make a p bond
This is the hybridization used in the carbons of ethene
Two sp orbitals are obtained from mixing one s and one p orbital
The geometry of the two orbitals is linear
The two leftover p orbitals are used to make two p bonds
This is the hybridization used in the carbons of ethyne
Sigma (s) bonds have circular symmetry when viewed along the bond axis
Pi (p) bonds result from sideways overlap of two p orbitals
chapter 1

70. Hybridization – is the mixing of two or more atomic orbitals in an atom (usually central atom) to form a new set of hybrid orbitals (same in shape and energy).
Mix at least 2 nonequivalent atomic orbitals (e.g. s and p).
Hybrid orbitals have different shape and energy from original atomic orbitals.
Number of hybrid orbitals is equal to the number of pure atomic orbitals used in the hybridization process.
Covalent bonds are formed by:
Overlap of hybrid orbitals with atomic orbitals
Overlap of hybrid orbitals with other hybrid orbitals

71. Hybridization of Carbon
sp3
CH4
sp2
H2C = CH2 sp
HC CH
chapter 1

72. sp3 hybridization in Methane CH4
excitation
becomes
Ground state
excited state

73. Molecule geometry of CH4
4 sp3 hybrid orbitals

74. sp2 hybridization in Ethene C2H4
energy

76. sp2 hybridization in Ethene C2H4
120 0

77. sp Hybridization in Acetylene C2H2

78. 180 0

80. What is the hybridization in each carbon atom?4 2 5 6 3 7 1
sp3 – 2, 5
tetrahedral
sp2 – 1, 3, 4
trigonal planar
sp – 6, 7
linear

81. What is the hybridization in each carbon atom?4 3 2 1