Introduction to Organic Chemistry CHEM 2124 – General Chemistry II Alfred State College Professor Bensley

Learning Objectives  Recognize the characteristic features of organic compounds.  Predict the shape around atoms in organic molecules.  Use shorthand notation to draw organic molecules.  Recognize the common functional groups and understand their importance.

Learning Objectives  Distinguish organic compounds from ionic inorganic compounds.  Determine whether or not an organic compound is polar or non-polar.  Determine solubility properties of organic compounds.

I. Introduction to Organic Chemistry Organic chemistry is the study of compounds that contain the element carbon.

II. Characteristics of Organic Compounds 1.All organic compounds contain carbon atoms and most contain hydrogen atoms. 2.Carbon forms single, double, and triple bonds to other carbon atoms. 3.Some compounds have chains of atoms and some compounds have rings.

II. Characteristics of Organic Compounds 4.Organic compounds may also contain elements other than carbon and hydrogen. THE RULE OF “HONC”

III. Drawing Organic Molecules A. Condensed Structures Some bond lines can be drawn in for effect or to show specific bonding.

III. Drawing Organic Molecules Identical groups can be condensed further: A. Condensed Structures

III. Drawing Organic Molecules B. Skeletal Structures

IV. Functional Groups A. Hydrocarbons Alkanes Alkenes Alkynes Aromatics B. Compounds Containing a Single Bond to a Heteroatom C. Compounds Containing a C=O (Carbonyl) group

V. Properties of Organic Compounds

A covalent bond is nonpolar when two atoms of identical or similar electronegativity are bonded. A. Polarity If the individual polar bonds (dipoles) cancel in a molecule, the molecule is nonpolar. If the individual bond dipoles do not cancel, the molecule is polar.

V. Properties of Organic Compounds The rule of solubility is “like dissolves like.” B. Solubility CH 3 CH 2 CH 2 CH 2 CH 2 CH 3 hexane small nonpolar molecule no O or N present H 2 O insoluble organic solvent soluble small polar molecule O atom present H 2 O soluble organic solvent soluble CH 3 CH 2 —OH ethanol cholesterol

VI. Shapes of Organic Molecules VSEPR theory: The most stable arrangement keeps the groups on a central atom as far away from each other as possible.

VI. Shapes of Organic Molecules To draw a 3-D tetrahedron in 2-D, we use: a solid line for bonds in the plane a wedge for a bond in front of the plane a dashed line for a bond behind the plane