Ch. 4 Structure and Stability

In the following chapters, we will frequently discuss several fundamental principles necessary to understand the reactivity of organic molecules.

Structural formulas

By definition, an organic molecule is said to be saturated if it contains no π bonds, and rings; it is unsaturated if it has at least one π bond or a ring. A saturated compound with n carbon atoms has exactly 2n+2 hydrogen atoms, while an unsaturated compound with n carbon atoms has fewer than 2n+2 hydrogens.

The formula below is used to determine the degree of unsaturation (d) of simple organic molecules:

(2n+2)-x/2

n: number of carbons

x: number of hydrogens

x: represents the number of hydrogens and any monovalent atoms (such as halogens F, Cl, Br, or I)

Since the number of oxygens has no effect, oxygens are ignored in calculating the degree of unsaturation

For nitrogen containing compounds, replace each N by 1 C and 1 H when using this formula.

One degree of unsaturation indicates the presence of one π bond or one ring; two degrees of unsaturation means there are two π bonds (two separate double bonds or one triple bond), or one π bond and one ring or two rings, and so on. The presence of heteroatoms can also effect the degree of unsaturated in a molecule. This is best illustrated through a series of related molecules that all have one degree of unsaturation.

Put the example of Butene from page 46 on this flashcard

Hybridization

Reaction Intermediates

Inductive Effects

Resonance Stabilization

Acidity

Electronegativity effects

Resonance Effects

Inductive Effects

Effects of substituents on acidity

Nucleophiles and Electrophiles

Leaving Groups

Ring Strain

Hydrogenation Reactions of Cyclopropane and Cyclobutane

Isomerism

Stereoisomerism

Chirality

Absolute Configuration

Enantiomers

Optical Activity

Diastereomers

Resolution of Enantiomers

Epimers

Anomers

Meso Compounds

Geometric Isomers