Review for Organic II

Review for Organic II

Valance Shell

• The Valance Shell is the outermost shell which contains at least one electron.

• In this example the 2s is the valance shell.

Nucleus

Valence Shell = 2s

1s

2s

1s Orbital

= Nucleus

= 1s Orbital

p Orbitalsy

x

z

y

x

z

= 2py Orbital

y

x

z

= 2pz Orbital

y

x

z

= 2px Orbital

sp3 Orbitals of Carbon (C)

1s

2s

2p

Normal

1s

2s

sp3 orbitals

2psp3

H

CH H

H

• Normally you have 1s orbital and 3p orbitals. However in the case of Carbon (C) the S and P orbitals merge to form the sp3 orbitals.

What is Electronegativity?

• Electronegativity is the desire of an atom to gain an additional electron to fill its octet or the strength of the atom to pull electrons.

• The higher number the stronger the electronegativity.– Largest electronegativity: F = 4.0, Cl = 3.5,

O = 3.5, N = 3.0, Br = 2.8, C = 2.5

Ionic Bonds

• Ionic Bonds are where an electron is donated to another atom. This creates two charged species. These charged atoms or molecules are normally free in solution but are held together when solid by electrostatic attractions.

Na + Cl Na+ + Cl-

gives up an electron

gains an electron

Na+

Na+

Na+

Cl-

Cl-Cl-

Solution Solid -crystals

Na+Cl- Na+

Cl- Na+Cl-

Covalent Bond

• Describes the sharing of electrons between two atoms. There are two different types of covalent bonds.– Nonpolar covalent bonds is defined as the even

distribution of electrons between 2 atoms.– Polar covalent bonds is defined as the uneven

distribution of electrons between two atoms.

Polar Covalent Bonds

• Describes the unequal sharing of electrons in a covalent bond.

C

O

R R

Electrons are around the oxygen 70%of the time Electrons are around the carbon 30%

of the time

• This makes the oxygen considered partially negative because the electrons around it more. The carbon is considered partially positive because the shared electrons are mainly around the oxygen.

Basic Carbon Structures: Carbon

Family Name Functional Group Simple Example Name Ending

Alkane -ane

Alkene

-ene

Alkyne

-yne

Arene

-none

C C

C C

C C

C CC

CCC

C C

H

H

H

H

HH

Ethane

Benzene

H

H

H

H

Ethene

C C HHEthyne

Naming Carbons Skeletons• 1 (Carbon) Meth-• 2 (Carbons) Eth-• 3 (Carbons) Prop-• 4 (Carbons) But- • 5 (Carbons) Pent-• 6 (Carbons) Hex-• 7 (Carbons) Hept-• 8 (Carbons) Oct-• 9 (Carbons) Non-• 10 (Carbons) Dec-

C

H

H

H H

C C

H H

H

H

H

H

C C

H H

H

H

H

C

H

H

H

C C

H H

H

H

H

C

H

H

C

H

H

H

C C

H H

H

H

H

C

H

H

C

H

C

H

H

H

H

C C

H H

H

H

H

C

H

H

C

H

C

H

H

C

H

H

H

H

C C

H H

H

H

H

C

H

H

C

H

C

H

H

C

H

H

C

H

H

H

H

C C

H H

H

H

H

C

H

H

C

H

C

H

H

C

H

H

C

H

H

C

H

H

H

H

C C

H H

H

H

H

C

H

H

C

H

C

H

H

C

H

H

C

H

H

C

H

H

H

C

H

H

H

C C

H H

H

H

H

C

H

H

C

H

C

H

H

C

H

H

C

H

H

C

H

H

H

C

H

H

C

H

H

H

Methane

Ethane

Propane

Butane

Pentane

Hexane

Heptane

Octane

Nonane

Decane

Basic Carbon Structures: Oxygen

Family Name Functional Group Simple Example Name Ending

Alcohol-ol

Ether -ether

Phosphate None None

C O H

C O C

C C

H

H

O H

H

H

H

Ethanol

C O P

O

O

O

C O C H

H

H

H

Methyl Ether

H

H

Basic Carbon Structures: Carboxyl

Family Name Functional Group Simple Example Name Ending

Carboxyl

Aldehyde -al

Ketone -one

Carboxylic acid -oic acid

Ester -oate

Carboxylic acid anydride

-oic anhydride

C

O

C C

O

H

C C

O

C

C C

O

O H

C C

O

O C

C C

O

O C

O

C

H C

H

H

C

O

O H

Acetic Acid

Basic Carbon Structures: Nitrogen

Family Name Functional Group Simple Example Name Ending

Amine -amine

Nitrile -nitrile

Nitro -none

Amide -amide

C N

C C N

C NO

O

C C

O

N

Basic Carbon Structures: Sulfur

Family Name Functional Group Simple Example Name Ending

Sulfide sulfide

Sulfoxide sulfoxide

Sulfonesulfone

Thiol -thiol

C S C

C S

O

C

C S

O

C

O

C S H

Common Functional GroupsFamily Name Functional Group Simple Example Name Ending

Ether -ether

Amine

-amine

Carboxyl -

Arene

-noneC C

CCC

C

C O C

C N

C

O

Kinds of Reactions

• Addition Reactions

• Elimination Reactions

• Substitution Reactions

• Rearrangement Reactions

Unsymmetrical Bond Breaking

• Unsymmetrical bond breaking - split bonds and gives both electrons to one atom. The most electronegative atom receives the both electrons.

A B A B+ -+

Symmetrical Bond Breaking

• Symmetrical bond breaking - split bonds and gives an electron to both atoms. The normally occurs when the electronegativity of the bond is the same.

A B A B+

Transitional State• The transitional state represents the

highest energy structure in this step of the reaction.

Reactions of Alkenes

C C

OHH

Alcohol

HH

OHHO

1,2-Diol

O

CO

XH

XX

OHX

Alkane

Carbonyl Compound

CyclopropaneEpoxide

1,2-Dihalide

Halide

Halohydrin

alkene

Chirality• If an object has a plane of symmetry it

is necessarily the same as its mirror image

• The lack of a plane of symmetry is called “handedness”, chirality

• Hands, gloves are prime examples of chiral object–They have a “left” and a “right” version

HO-

H3C

H

H3CH2C

BrHO

H CH3

CH2CH3

Br

H3C

H

H3CH2C

Br

(S)-2Bromobutane Transition State

+HO-

CH3

H

CH2CH3

HO

(R)-2-Butanol

+ Br-

The SN2 Reaction

Stereochemistry of SN1 Reaction

• The planar intermediate should lead to loss of chirality– A free

carbocation is achiral

• Product should be racemic

Basic Carbon Structures: Alkane

C C

Basic Carbon Structure: Alkene

C C

Basic Carbon Structure: Alkyne

C C

Basic Carbon Structure: Alcohol

C O H

Basic Carbon Structure: Ether

C O C

Basic Carbon Structure: Carboxyl

• Carboxyl is found in a number of functional groups.

• It is reactive and is often used in organic reactions.

C

O

Basic Carbon Structure: Aldehyde

C C

O

H

Basic Carbon Structure: Ketone

C C

O

C

Basic Carbon Structure: Carboxylic Acid

C C

O

O H

Basic Carbon Structure: Ester

C C

O

O C

Basic Carbon Structure: Amine

C N

Basic Carbon Structure: Imine

C C N

Basic Carbon Structure: Nitrile

C C N

Basic Carbon Structure: Nitro

C NO

O

Basic Carbon Structure: Amide

C C

O

N

Basic Carbon Structure: Sulfide

C S C

Basic Carbon Structure: Sulfoxide

C S

O

C

Basic Carbon Structure: Sulfone

C S

O

C

O

Basic Carbon Structure: Thiol

C S H