Aim # 37: What is Organic Chemistry. H. W. # 37. Study class notes Aim # 37: What is Organic Chemistry? H.W. # 37 Study class notes Complete the handout sheet Do Now: Look at the tag on your shirt or have someone at your table look at your tag for you. Which fabrics are in your shirt?

Natural vs. Synthetic Cloths Cotton, silk, linen, wool → natural fabrics Processing natural fabrics – very expensive! A cheaper alternative – synthetics (rayon, nylon, polyester) But what do we need to synthesize a fabric?

Organic Chemistry Organic Chemistry is the study of molecules containing carbon. Called ‘organic’ (of an organism), because: Many natural products contain carbon; and Living beings use the special properties of carbon to make biological macromolecules (sugars, amino acids, fats, DNA, etc.)

Why study Organic Chemistry? Carbon is versatile- it can form an endless variety of structures (molecules) with itself and other atoms. Even a small change to the structure can mean a huge change to the molecule!

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Applications of Organic Chemistry Organic Chemistry is also used to make pharmaceuticals plastics even artificial limbs

Starting Simply- Allowable Bonds OK – lets begin our journey through organic chemistry. Draw the Lewis dot structures for the following atoms: Carbon Nitrogen Oxygen; and Hydrogen

Allowable Bonds cont’d Based on the drawings you just made, what is the maximum number of bonds that can be made by: Carbon? Nitrogen? Oxygen? Hydrogen? These four elements are the main elements in organic chemistry.

Allowable Bonds cont’d Now look at the number of holes in the model kit ‘atoms’ for: Carbon (black) Nitrogen (blue) Oxygen (red) Hydrogen (yellow) Do you notice a pattern?

So What? 4 single bonds 1 double bond and 2 single bonds This ‘allowable bond’ thing is very important. Because carbon has the greatest number of ‘bonding sites’, it can bond in many ways 4 single bonds 1 double bond and 2 single bonds 2 double bonds; or 1 triple bond and 1 single bond Which of the following … … are allowable structures based on the maximum number of allowable bonds?

Questions for thought Why would carbon generally not have a quadruple bond? Why does hydrogen have to be at the ‘outside’ of a molecule?

Drawing an Organic Molecule So far we have looked at the expanded structural formulas of organic molecules- these structures show all of the atoms and bonds. Sometimes, you’ll see a condensed structural formula that does not show all the bonds. e.g. CH3–CH2–CH2–CH3 or CH3CH2CH2CH3 Very often, you will see the line structure, that uses lines instead of showing carbons and hydrogens.

Expanded Structural Formula Condensed Line Structure

Expanded Structural Formula Condensed Line Structure

Structural Isomers Sometimes, one molecular formula can have more than one structural formula. For example, I could write the formula C3H6O in the following ways: OH H3C CH2 O H3C CH3 H3C H2C O

Isomer Practice C3H6? Hint: the carbons form a ring. C4H10? C3H8O? What are the possible isomers for: C3H6? Hint: the carbons form a ring. C4H10? C3H8O?