1. Introduction to Organic Molecules & Functional Groups
CHAPTER 11
Introduction to Organic Molecules & Functional Groups
General, Organic, & Biological Chemistry
Janice Gorzynski Smith

2. CHAPTER 11: Intro to Organic Molecules & Functional Groups
Learning Objectives:
Difference between organic and inorganic molecules
Name characteristic features of organic compounds
Draw organic compounds, including skeletal structures
Identify common bond types, angles, and molecule shapes
Name functional groups
Understand polarity and its effect on solubility and boiling point
Explain the difference between fat and water soluble vitamins
Smith. General Organic & Biolocial Chemistry 2nd Ed.

3. CHAPTER 11: Intro to Organic Molecules & Functional Groups
Lecture Outline:
Define Organic Chemistry
Review the shape of organic molecules
How to Draw organic compounds
Overview of functional groups
Review intermolecular forces
Review polarity
Smith. General Organic & Biolocial Chemistry 2nd Ed.

4. Smith. General Organic & Biolocial Chemistry 2nd Ed.
Organic Chem
Definition
Organic Chemistry is the study of compounds containing carbon.
Both naturally occurring and synthetic compounds
C, H, O, N, S, P, Halides (Cl, F, Br, I)
Smith. General Organic & Biolocial Chemistry 2nd Ed.

5. Brainstorm examples of organic and inorganic compounds.
Group
Problem
Brainstorm examples of organic and inorganic compounds.

6. Smith. General Organic & Biolocial Chemistry 2nd Ed.
Organic Chem
Definition
Methane gas
Pregnenolone; hormone in adrenal glad and brain
FOXP2 protein
Smith. General Organic & Biolocial Chemistry 2nd Ed.

7. Smith. General Organic & Biolocial Chemistry 2nd Ed.
Organic Chem
Bonding
Covalent Bond?
Valence electron?
Octet Rule?
Smith. General Organic & Biolocial Chemistry 2nd Ed.

8. Smith. General Organic & Biolocial Chemistry 2nd Ed.
Organic Chem
Bonding
A COVALENT BOND shares a pair of electrons between atoms.
non-metal to non-metal bond
The OCTET RULE states that atoms of main group elements make bonds by gaining, losing, or sharing electrons to achieve an outer shell containing 8 electrons.
How many valence electrons do Carbon and Hydrogen have?
Oxygen?
Nitrogen?
Sulfur?
Phosphorous?
Chlorine?
Smith. General Organic & Biolocial Chemistry 2nd Ed.

9. How many bonds does each atom need to satisfy the octet rule? C H O N
Group
Problem
How many bonds does each atom need to satisfy the octet rule? C H O N S P

10. Draw these molecules: Ethane: C2H6 Cyclohexane: C6H12 Propene: C3H6
Group
Problem
Draw these molecules:
Ethane: C2H6
Cyclohexane: C6H12
Propene: C3H6
Propyne: C3H4

11. Smith. General Organic & Biolocial Chemistry 2nd Ed.
Molecule Shape
Bond Angle
VSEPR Theory: The most stable arrangement of atoms in a molecule maximized the distance between atoms and lone pairs.
Use modeling kit!
Smith. General Organic & Biolocial Chemistry 2nd Ed.

12. What are the bond angles within the molecules?
Group
Problem
Draw the lewis dot structures for water and ethanol. How many lone pairs of electrons do they have?
What are the bond angles within the molecules?

13. What are the bond angles within the molecule?
Group
Problem
Draw the lewis dot structure for ammonia. How many lone pairs of electrons does it have?
What are the bond angles within the molecule?

14. Smith. General Organic & Biolocial Chemistry 2nd Ed.
Molecule Shape
Drawing Molecules
SIMPLIFY!
H H H H H
C C C C H
H H H H
Use modeling kit!
CH3CH2CH2CH3
Smith. General Organic & Biolocial Chemistry 2nd Ed.

15. Group
Problem
Practice: 1) convert to condensed structure 2) simplify further if possible 3) skeletal structure

16. Smith. General Organic & Biolocial Chemistry 2nd Ed.
Functional Groups
Overview
Alkane
Alkene
Alkyne
Aromatic
C − C
C = C
Hydrocarbon
Functional
Groups
Use modeling kit!
Smith. General Organic & Biolocial Chemistry 2nd Ed.

17. Smith. General Organic & Biolocial Chemistry 2nd Ed.
Functional Groups
Overview
Alkyl halides
Alcohols
Ethers
Amines
Single Bond
to a
Heteroatom
Functional
Groups
Use modeling kit!
Smith. General Organic & Biolocial Chemistry 2nd Ed.

18. Smith. General Organic & Biolocial Chemistry 2nd Ed.
Functional Groups
Overview
Aldehydes
Carboxylic Acids
Esters
Ketones
Amides
Carbonyl
Functional
Groups
Use modeling kit!
pentanal
Ethanoic acid (or acetic acid)
Methyl propanoate
propanol
Smith. General Organic & Biolocial Chemistry 2nd Ed.

19. Identify all of the functional groups
Problem
Identify all of the functional groups
pentabromodiphenyl ether

20. Identify all of the functional groups
Problem
Identify all of the functional groups
Estradiol
Genistein
A soy isoflavone

21. Group
Problem
Identify all of the functional groups (other then alkanes) in Gliadin C29H41N7O9

22. Properties of Organics Overview
Organic compounds experience weaker intermolecular interactions because they form covalent bonds.
no ion-ion interactions
Usually clear or yellowish color
Often a liquid or a gas at room temperature
Lower melting points and boiling points relative to ionic compounds
Use modeling kit!
Smith. General Organic & Biolocial Chemistry 2nd Ed.

23. Properties of Organics Polarity
The difference in electronegativity between two atoms bonded together creates a polar dipole moment. The more electronegative atom has a slight negative charge (more electron density).
Use modeling kit!
Smith. General Organic & Biolocial Chemistry 2nd Ed.

24. Group
Problem
What is the dipole moment of each bond, and what is the overall dipole moment for each molecule?
Water
Acetone
Isopropanol
Acetic Acid
Diethyl Ether

25. Intermolecular Forces
Properties of Organics
Intermolecular Forces
Intermolecular Forces
weaker then intramolecular forces (bonding)
London Dispersion
Dipole-Dipole
Hydrogen Bonding
Instantaneous dipole-induced attractions that occur between all molecules, even non-polar.
Partial charges of polar compounds attract each other .
Strong dipole-dipole attraction when H is covalently bonded to a highly electronegative atom.
No ion-ion interactions because all covalent bonds so no formal charges.
Smith. General Organic & Biolocial Chemistry 2nd Ed.

26. Intermolecular Forces
Properties of Organics
Intermolecular Forces
Intermolecular Forces
weaker then intramolecular forces (bonding)
London Dispersion
Use modeling kit!
Smith. General Organic & Biolocial Chemistry 2nd Ed.

27. Intermolecular Forces
Properties of Organics
Intermolecular Forces
Intermolecular Forces
weaker then intramolecular forces (bonding)
Dipole-Dipole
Use modeling kit!
Smith. General Organic & Biolocial Chemistry 2nd Ed.

28. Intermolecular Forces
Properties of Organics
Intermolecular Forces
Intermolecular Forces
weaker then intramolecular forces (bonding)
Hydrogen Bonding
Use modeling kit!
Smith. General Organic & Biolocial Chemistry 2nd Ed.

29. Rank the three intermolecular forces discussed in order of strength.
Group
Problem
Rank the three intermolecular forces discussed in order of strength.

30. LIKE DISSOLVES LIKE Properties of Organics Solubility
polar molecules dissolve in polar solvents
nonpolar molecules dissolve in nonpolar solvents
Polar Solvents
Nonpolar Solvents
Water: H2O
Pentane: C5H12
Methanol: CH3OH
Hexane: C6H14
Ethanol: CH3CH2OH
Cyclohexane: C6H12
Acetone: (CH3)2CO
Benzene: C6H6
Acetic Acid: CH3CO2H
Toluene: CH3C6H5
Ammonia: NH3
Chloroform: CHCl3
Acetonitrile: CH3CN
Diethylether: (CH3CH2)2O
Use modeling kit!
Smith. General Organic & Biolocial Chemistry 2nd Ed.

31. Group
Problem
Draw all of the solvents from the previous slide and prove they are polar or nonpolar.

32. Properties of Organics Water & Fat Soluble Vitamins
Which type of solvent would the following molecules dissolve in?
Use modeling kit!
Vitamin A
Vitamin B12 32
Smith. General Organic & Biolocial Chemistry 2nd Ed.

34. NH3   H  N   H   H    H  N  H    H   H N H H
Molecules
BONDING: Lewis Bond Theory
strategy to tackle problems
NH3
Start with the least electronegative element as the central element
Surround the central element with the bonding elements and indicate their initial electrons
Add extra electrons, from surrounding atoms, to the central atom to satisfy the octet rule
Use multiple bonds if necessary   H  N   H   H    H  N  H    H   H N H H

35.  H   NH3  N H     H      H  N H N H H     H H
Molecules
BONDING: Lewis Bond Theory
strategy to tackle problems  H  
NH3  N H  
Initial electron bookkeeping:
Find the difference, this is the number of electrons that must be shared
÷ 2 to know the # of bonds shared
Arrange atoms around the most electronegative element
Final electron bookkeeping:   H
Need: 3x(1H x 2 e-) + (1N x 8 e-) = 14 e-
Have: 3x(1H x 1 e-) + (1N x 5 e-) = 8 e-
(14 e-) – (8 e-) = 6 e-
(6 e-) ÷ 2 = 3 bonds      H  N H N H H     H H