1. Chapter 1: Bonding and Molecular Structure CH 1-1 Introduction-Lewis Structures-Formal Charge
Chemical formula and Lewis Structures
Formal Charge
Covalent bonds (sigma and pi)
Hybridization
Molecular geometry
Constitutional Isomers
Dash formula, condensed formula, zig-zag formula

2. Lewis Structures of Simple Organic Molecules
How many Valence Electrons at each atom?

3. Lewis Structures of Simple Organic Molecules
How many Covalent Bonds to each atom?
Try drawing possible Lewis Structures

4. Lewis Structures of Simple Organic Molecules
Lewis Structures or Dash Formulas:
(ethanol)
(dimethyl ether)

5. Lewis Structures of Charged Organic Molecules: Formal Charge for an Atom
[C2H3O2]-1
FC(atom) = # Valence electrons - # Owned electrons FC(atom) = VE(atom) – OE(atom) OE = total # bonds + # lone pair electrons

6. FC(atom*) = VE(atom*) – OE(atom*)-1 +1 +1 -1

7. Summary: Formal Charge for C, O, N
CARBON
4 bonds = neutral charge (normal # of bonds)
3 bonds = +1 (no lone pairs) or -1 (one lone pair)
5 bonds = never, never, never, never, never……
OXYGEN
2 bonds = neutral charge (normal # of bonds)
1 bond = -1 charge
3 bonds = +1 charge (i.e., hydronium ion)
NITROGEN
3 bonds = neutral charge (normal # of bonds)
2 bonds = -1 charge
4 bonds = +1 charge (i.e., ammonium ion)
HALOGENS
1 bond = neutral charge (normal # of bonds
No bonds = -1 charge (halide ions)
2 bonds = +1 charge (very rare; halonium ion)