Download Chapter One: Molecular Structure

Outline Chapters One and Two: Klein
Bonding, Electronic Structural Models and Drawing Organic Molecules
1. Introduction to Organic Chemistry
2. What you need to remember from General Chemistry
3. Drawing Lewis Structures
a. Octet vs non-octet structures
b. e- book-keeping for octet structures:
o #bonds = [Need-Have]/2
o Need = # needed for filled shell around each atom (8 or 2 multiplied
by # heteroatoms or hydrogen atoms, respectively)
o Have = # valence electrons each atom brings to the table
4. Formal Charge
Formal Charge= e- gained or lost = (Valence) – (e- “owned” by atom in structure)
5. Resonance
a. Atoms are stationary- only e- move
b. Energy Consequences
c. Relative Importance
o # bonds
o Octet
o Charge on Complimentary Atoms (negative on more
electronegative atom)
o Minimization of charge separation
6. Drawing Organic Structures
a. Bond-line
b. Wedge-dash
7. Functional Groups in Organic Chemistry
8. Atomic orbitals
a. Unhybridized s, p and d
b. Shapes and energies
c. Hybridization to sp, sp2 and sp3
9. Formation of Molecular Orbitals
a. Shapes and Energies
b. Frontier Molecular Orbital Energy Diagrams
c. Molecular Orbitals
LEARNING OUTCOMES:
 Gain Appreciation for relevance of Organic Chemistry to everyday experience
 Draw Organic Molecules using modified Lewis Structures
 Understand electron distribution in molecules with the concept of Resonance
 Visualize shapes of simple Organic Molecules
 Predict Hybridization States
 Describe Bonding according to Molecular Orbital Theory
SAMPLE PROBLEMS:
Outline Chapters One and Two: Klein
Bonding, Electronic Structural Models and Drawing Organic Molecules
1)
A) Complete the following Lewis Structure of neutral CH2N2 including any multiple
bonds, non-bonded electrons and formal charges.
B) Draw a second valid resonance form. Include non-bonded electrons and formal
charges.
C) Label each resonance form as a MAJOR, MINOR, or EQUAL contributor to the
overall structure.
2) Consider the Molecular Orbital Energy Diagram for acetylene C2H2 below:
E
To H
To H
A) Identify the hybridized atomic orbitals in the diagram. Label their positions on
the diagram.
B) Label each Molecular Orbital whose energy is depicted in the diagram as a , *,
 or * orbital.
C) Tell whether the C2H2+ or C2H2– is more stable. Explain.
D) Label the LUMO(s) in the diagram.
Outline Chapters One and Two: Klein
Bonding, Electronic Structural Models and Drawing Organic Molecules
3) Which of the following best describes the bonding for the indicated bond in the
structure below?
A) Csp3 + Osp2
B) Csp3 + Osp
C) Csp2 + O sp3
D) C sp2 + Osp
E) Csp2 + Op