ChemPhys UNIT 7: Organic Chemistry

1. Chemistry & Physics
UNIT 7: ORGANIC CHEMISTRY

2. Chemistry
Periodic table
Chemical reaction
Matter
Atoms
Chemical bonding
Electrolytes
Hydrocarbons
Organic chemistry

3. Today
• Introduction
– Organic vs. Inorganic
– Formulas
– Isomerism
• Alkanes
– Naming
• Alkenes and alkynes
– Naming
– Geometric isomers
– Biologically important alkenes

4. PreQuiz
1. Which of the following is an organic substance?
a) Water; b) Salt; c) Diamond
2. What type of bonding is usually found in organic compounds?
a) Covalent bonding; b) Ionic bonding; c) Hydrogen bonding
3. The molecular and emperical formula of ethane are _____?
a) C2H6 / C2H6; b) C2H6 / CH3; c) C2H6 / C4H12
4. HC≡CH is part of the family of the _____?
a) Alkanes; b) Alkenes; c) Alkynes
5. Alkanes react primarily by _____?
a) Neutralization; b) Substitution; c) Addition
6. Haloalkanes are often used as _____?
a) Disinfectant; b) Anestetics; c) Hormones
7. β-carotene is a(n)_____?
a) Plant hormone; b) Aromatic ; c) Precursor of Vitamin A
8. Cis- and trans-2-butene are examples of _____?
a) cycloalkenes; b) geometric isomers; c) lazy chemicals
9. What is the name of the following compound:
a) 3-methyl-1-butene; b) 2-methyl-3-butyne; c) 3-methyl-1-butane

5. Organic chemistry
BONDING
FORMULAS
ISOMERS

6. Organic materials
ORGANIC
MATTER
Chemistry of life
Sackheim’s Chemistry: Chapter 14

7. Organic vs. inorganic
Organic Inorganic
Based on C Not based on C
Nonelectrolyte Electrolyte (acids, bases, salts)
Covalent bonding Ionic bonding
Low boiling and melting point High boiling and melting point
Soluble in nonpolar solvents Soluble in polar solvents (water)
Complex structure Simple structure
Millions of compounds Thousands of compounds
Sackheim’s Chemistry: Chapter 14
Unique
Covalent bonds with itself
Covalent bonds with others

8. C-C bonds
• Carbon-Carbon (C-C) bond
– Unique: covalent bonds with other C atoms
– 4 valence (outer) electrons: maximum of 4 covalent bonds
Sackheim’s Chemistry: Chapter 14
Covalent bonds
“Sharing electrons”

9. C-C compounds
Graphite
Good electrical
conduction
Diamond
Hardest natural
substance
Fullerene Nanotube
Sackheim’s Chemistry: Chapter 14
Create Carbon

10. C-H bonds
• Carbon-Hydrogen (C-H) bond
– Each carbon atom forms 4 bonds: octet rule
– Each hydrogen atom form 1 bond
– Alkane: single bond
– Alkene: double bond
– Alkyne: triple bond
Sackheim’s Chemistry: Chapter 14
Alkane
Alkene
Alkyne

11. Other C bonds
• Carbon-Oxygen (C-O) and Carbon-Fluor (C-F) bond
– Each carbon atom forms 4 bonds: octet rule
– Each oxygen atom forms 2 bonds (double bond): octet rule
– Each fluor atom forms 1 bond: octet rule
Sackheim’s Chemistry: Chapter 14

12. Formulas
• Definition
– Group of symbols that represent the
elements present in a substance
• Molecular formula
– Written formula
– Presents actual number of atoms in the
substance
– Cannot tell the structure
• Structural formula
– 2D view of structure
– Presents connection between atoms
Sackheim’s Chemistry: Chapter 14
“ISOMERS”

13. Isomerism
• Isomers
– Same molecular structure
– Different structural formula: different properties
Boiling point = 78 °C
liquid
-25 °C
gas
Sackheim’s Chemistry: Chapter 14

14. Nomenclature
• Naming of chemical compounds
– Via IUPAC system
Carbon
atoms
Alkanes Alkenes Alkynes
1 CH4: methane - -
2 C2H6: ethane C2H4: ethene C2H2: ethyne
3 C3H8: propane C3H6: propene C3H4: propyne
4 C4H10: butane C4H8: butene C4H6: butyne
5 C5H12: pentane C5H10: pentene C5H8: pentyne
6 C6H14: hexane C6H12: hexene C6H10: hexyne
Sackheim’s Chemistry: Chapter 15,16

15. Saturated hydrocarbons
NAMES
STRUCTURE
PROPERTIES
USE

16. Source of hydrocarbons
Sackheim’s Chemistry: Chapter 15
Natural gas
Petroleum

17. Alkanes
• Hydrocarbons = compounds with C and H only
– SATURATED (alkanes): single bonds
Sackheim’s Chemistry: Chapter 15
Methane: (CH4) General formula: CnH2n+2

18. Free rotation vs. isomers
• Same compounds
– Rotation of C-C single bonds
– All structures are the same
– C4H10: butane
• Isomer
– Same molecular formula
– Different structural formula
– C4H10: iso-butane
Sackheim’s Chemistry: Chapter 15

19. Lazy scientists
• Condensed structural formulas
CH3-CH2-CH2-CH3
CH3CH2CH2CH3
CH3(CH2)2CH3
degreeoflaziness
Sackheim’s Chemistry: Chapter 15

20. Nomenclature alkanes
• IUPAC system
1. Search for longest carbon
chain (head chain) and name it
2. Number the carbon atoms of
the head chain
3. Search for side groups that are
not part of head chain and
name them
Carbon
atoms
Head chain Side group
1 CH4: methane –CH3: methyl
2 C2H6: ethane –C2H5: ethyl
3 C3H8: propane –C3H7: propyl
4 C4H10: butane –C4H9: butyl
5 C5H12: pentane –C5H11: pentyl
6 C6H14: hexane –C6H13: hexyl
7 C7H16: heptane –C7H15: heptyl
8 C8H18: octane –C8H17: octyl
9 C9H20: nonane –C9H19: nonyl
10 C10H22: decane –C10H21: decyl
Sackheim’s Chemistry: Chapter 15

21. Practice (1)
• IUPAC system
1. Search for longest carbon
chain (head chain) and name it
2. Number the carbon atoms of
the head chain
3. Search for side groups that are
not part of head chain and
name them
Butane
2-methylbutane
Octane
2,3-dimethyl-4-ethyloctane
1 2 3 4
8 7 6 5 4 3 2 1
Sackheim’s Chemistry: Chapter 15

22. Practice (2)
2-ethyl-3-chloro-4-methylheptane
1 2 3 4 5 6 7
Sackheim’s Chemistry: Chapter 15

23. Cycloalkanes
• Shape of ring
– Prefix: cyclo-
– Structures can be abbreviated with geometric shape
Sackheim’s Chemistry: Chapter 15

24. Properties
Carbon
atoms
Formula and
name
Boiling
point (°C)
State of
matter
1 CH4: methane -162 Gas
2 C2H6: ethane -89 Gas
3 C3H8: propane -42 Gas
4 C4H10: butane 0 Gas
5 C5H12: pentane 36 Liquid
6 C6H14: hexane 69 Liquid
7 C7H16: heptane 98 Liquid
8 C8H18: octane 126 Liquid
9 C9H20: nonane 151 Liquid
10 C10H22: decane 174 Liquid
Sackheim’s Chemistry: Chapter 15

25. Combustion
• Complete combustion
– Alkanes react with oxygen to produce carbon dioxide, water and energy
• Incomplete combustion
– Alkanes produce also carbon monoxide (poisoning) due to insufficient O2
Sackheim’s Chemistry: Chapter 15

26. Halogenation
• Substitution
– Alkanes react with halogens (F2, Cl2, Br2, I2)
– Halogen (F, Cl, Br, I) replaces hydrogen (H)
– Product: haloalkane
bromomethane
chloromethane dibromomethanetriiodomethane
Sackheim’s Chemistry: Chapter 15
substitution

27. Anesthetics
Sackheim’s Chemistry: Chapter 15
cyclopropane chloroethane
“chloral hydrate” “halothane”

28. Unsaturated hydrocarbons
NAMES
STRUCTURE
PROPERTIES
USE

29. Alkenes
• Hydrocarbons = compounds with C and H only
– SATURATED (alkanes): single bonds
– UNSATURATED (alkenes or alkynes): double or triple bonds
Sackheim’s Chemistry: Chapter 16
Ethene: (C2H4) General formula: CnH2n

30. Cycloalkenes
• Shape of ring
– Prefix: cyclo-
– Structures can be abbreviated with geometric shape
Sackheim’s Chemistry: Chapter 16

31. Alkynes
• Hydrocarbons = compounds with C and H only
– SATURATED (alkanes): single bonds
– UNSATURATED (alkenes or alkynes): double or triple bonds
Sackheim’s Chemistry: Chapter 16
Ethyne: (C2H2) General formula: CnH2n-2

32. Nomenclature alkenes and alkynes
• IUPAC system
1. Search for longest carbon chain (head chain) with double/triple bond
and name it
2. Number the carbon atoms of the head chain and give lowest number
possible to double bond
3. Search for side groups that are not part of head chain and name them
Carbon
atoms
Alkanes Alkenes Alkynes
1 CH4: methane - -
2 C2H6: ethane C2H4: ethene C2H2: ethyne
3 C3H8: propane C3H6: propene C3H4: propyne
Sackheim’s Chemistry: Chapter 16

33. Practice (3)
• IUPAC system
1. Search for longest carbon chain (head chain) with double/triple bond
and name it
2. Number the carbon atoms of the head chain and give lowest number
possible to double bond
3. Search for side groups that are not part of head chain and name them
Sackheim’s Chemistry: Chapter 16
Butene
1-butene
3-methyl-1-butene
4 3 2 1
Cyclohexene
1-cyclohexene
3-methyl-1-cyclohexene
1 2
5 4
6 3

34. Practice (4)
• IUPAC system
1. Search for longest carbon chain (head chain) with double/triple bond
and name it
2. Number the carbon atoms of the head chain and give lowest number
possible to double bond
3. Search for side groups that are not part of head chain and name them
Sackheim’s Chemistry: Chapter 16
Octyne
2-octyne
4,4-dibromo-5-ethyl-6-methyl-2-octyne
1 2 3 4 5 6 7 8

35. Practice (5)
• IUPAC system
1. Search for longest carbon chain (head chain) with double/triple bond
and name it
2. Number the carbon atoms of the head chain and give lowest number
possible to double bond
3. Search for side groups that are not part of head chain and name them
Sackheim’s Chemistry: Chapter 16
3,4-diethyl-2-hexene
1 2 3 4 5 6

36. Addition
• Reactions with alkenes/alkynes
– Addition: from unsaturated to saturated
Sackheim’s Chemistry: Chapter 16
hydrogenation
halogenation

37. Geometric isomers
no free rotation
“Same molecular formula but different structural formula”
same side opposite side
4 °C 0 °C
Sackheim’s Chemistry: Chapter 16

38. Biological importance
• Ethene
– Plant hormone (ripening fruits)
• Linoleic acid
– Found in nuts and oils (essential for body)
• Arachidonic acid
– Found in meat, eggs, diary (essential for body)
• β-carotene
– In fruits and vegetables (precursor vitamin A)
• Vitamin A
– From β-carotene (essential for body)
• Isoprene
– Present in natural rubber (industrial use) Sackheim’s Chemistry: Chapter 16

39. Aromatics
• Unsaturated hydrocarbons
– Pleasant odor
– Special ring-shaped structure
Sackheim’s Chemistry: Chapter 16

40. Benzene derivatives
Toluene
XylenePhenanthrene
TNT
Sackheim’s Chemistry: Chapter 16

41. PostQuiz
1. Which of the following is an organic substance?
a) Water; b) Salt; c) Diamond
2. What type of bonding is usually found in organic compounds?
a) Covalent bonding; b) Ionic bonding; c) Hydrogen bonding
3. The molecular and emperical formula of ethane are _____?
a) C2H6 / C2H6; b) C2H6 / CH3; c) C2H6 / C4H12
4. HC≡CH is part of the family of the _____?
a) Alkanes; b) Alkenes; c) Alkynes
5. Alkanes react primarily by _____?
a) Neutralization; b) Substitution; c) Addition
6. Haloalkanes are often used as _____?
a) Disinfectant; b) Anestetics; c) Hormones
7. β-carotene is a(n)_____?
a) Plant hormone; b) Aromatic ; c) Precursor of Vitamin A
8. Cis- and trans-2-butene are examples of _____?
a) cycloalkenes; b) geometric isomers; c) lazy chemicals
9. What is the name of the following compound:
a) 3-methyl-1-butene; b) 2-methyl-3-butyne; c) 3-methyl-1-butane

42. The End