Organic Chemistry Aromatics (Arenes) C H

C11-5-14 NAMING AND DRAWING Vocabulary & Concepts arene resonance OUTCOME QUESTION(S): C11-5-14 NAMING AND DRAWING Name and draw structural models of simple and branched alkanes. Include: complete structural formula, molecular formula, general formula, isomers branched alkenes and alkynes. Compare and contrast the structure and uses of aromatic and aliphatic hydrocarbons. Vocabulary & Concepts arene resonance

Benzene is the most common aromatic compound. Aromatic Compounds Cyclical hydrocarbons with delocalized electron sharing across single/ double bonds. Unsaturated Originally named because of their smell/odour This way of representing organic compounds is called a “line structure” Benzene is the most common aromatic compound.

The shifting electrons create two correct representations Electrons participating in the double bonds are actually shared by all carbons – delocalized. H C H C C H H H C C C H The shifting electrons create two correct representations Resonance: When one or more correct structures can be drawn for a compound.

naturally occurring in crude oil a known carcinogen H C H C C H H H C C C The moving electrons create 1½ bonds everywhere instead of double bonds H Benzene (C6H6): naturally occurring in crude oil a known carcinogen colorless, highly flammable liquid important industrial solvent and precursor

Benzene and all modified compounds of benzene are called arenes modified benzene compounds

These two are called optical isomers Common aromatic smells: These two are called optical isomers Citrus fruits Limonene C10H16 Almonds Benzaldehyde C7H6O Spearmint / Caraway Carvone C10H14O

Common aromatic smells: Licorice Glycyrrhizin C42H62O16

Common aromatic compounds: Adrenaline 4-(1-Hydroxy-2-(methylamino)ethyl)-1,2-benzenediol C9H13NO3 Caffeine 1,3,7-Trimethylpurine-2,6-dione C8H10N4O2 Now you know why these have common names Testosterone 17β-hydroxy-10,13-dimethyl-1,2,6,7,8,9,11,12,14,15,16,17- tetradecahydrocyclopenta[a]phenanthren-3-one C19H28O2

Naming Arenes Benzene is ONLY the parent chain when the ring is off an end (1st) carbon of a linear alkane. As a branch the benzene ring is called a phenyl group. Branches named as per the rules for alphatics CH2 - CH2 - CH3 1 CH3 - CH2 - CH - CH3 4 3 2 1 butylbenzene 2-phenylbutane

methylbenzene or "toluene" butylbenzene CH2 - CH = CH2 CH3 - CH2 - CH - CH3 3-phenylpropene 2-phenylbutane CH3 CH2 - CH2 - CH2 - CH3 methylbenzene or "toluene" butylbenzene This is such a commonly used compound that it has a “slang” name - toluene

3-methyl-1-phenylbutane Name this compound: CH2 - CH2 - CH - CH3 CH3 - 1 2 3 4 3-methyl-1-phenylbutane

This is another common compound called xylene Double substituted benzene compounds use special prefixes to denote the location: 1,2 – ortho 1,3 – meta 1,4 – para CH3 CH3 CH3 o-dimethylbenzene m-dimethylbenzene p-dimethylbenzene This is another common compound called xylene

p-bromomethylbenzene m-ethylmethylbenzene Name these compounds: Br CH3 CH2CH3 o-diethylbenzene p-bromomethylbenzene p-bromotoluene CH2CH3 CH3 m-ethylmethylbenzene m-ethyltoluene

C11-5-14 NAMING AND DRAWING Vocabulary & Concepts arene resonance CAN YOU / HAVE YOU? C11-5-14 NAMING AND DRAWING Name and draw structural models of simple and branched alkanes. Include: complete structural formula, molecular formula, general formula, isomers branched alkenes and alkynes. Compare and contrast the structure and uses of aromatic and aliphatic hydrocarbons. Vocabulary & Concepts arene resonance