Organic Chemistry

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Organic Chemistry

• 1. Study of carbon or organic compounds
• 2. Carbon major element in biological compounds

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Organic vs Inorganic

• 1. Organic- all have carbon, covalent bonds, low
  melting boiling points, most are nonpolar
  nonelectrolytes
• 2. Inorganic- Metal salts oxides, ionic or
  polar bonds, high melting boiling points, most
  are polar electrolytes

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Hydrocarbons

• 1. Contain only C H
• 2. Alkanes, alkenes, alkynes, aromatics

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Alkanes

• 1. Only single C-C bonds, CH4
• 2. Saturated hydrocarbons, every C is bonded to
  four atoms
• 3. Examples- CH4, methane C2H6, ethane C3H8,
  propane C4H10, butane C5H12, pentane . . .

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Alkenes

• 1. At least one double CC
• 2. Unsaturated
• 3. Examples- C2H4, ethene (ethylene) C3H6,
  propene
• C4H8, 1-butene or 2-butene . . .

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Alkynes

• 1. At least one triple C C bond
• 2. Unsaturated
• 3. Examples- C2H2, ethyne (acetylene) C3H4,
  propyne
• C4H6, 1-butyne or 2-butyne . . .

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Aromatics

• 1. One or more benzene rings, 6-C ring with
  alternating single double bonds
• 2. Example- C6H6, benzene naphthalene, C10H8

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Aromatic Examples

• 1. Benzene
• 2. Naphthalene

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Naming Alkanes
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Structural Formula, Alkanes

• 1. CH4
• 2. C2H6
• 3. C3H8
• 4. C4H10
• . . .

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Alkane Properties

• 1. Physical Properties
• 2. Chemical Properties

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Physical Properties

• 1. CH4 to C4H10 are gases, C5H12 to C17H36 are
  liquids, C18H38 and above are waxy solids at STP
• 2. All alkanes are nonpolar
• 3. Liquid alkanes are less dense than water

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Chemical Properties

• 1. Least reactive of organic compounds, but
• 2. Combine readily with oxygen, combustion

C3H8 5O2 ? 3CO2 4H2O Heat
C5H12 8O2 ? 5CO2 6H2O Heat
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Branched Alkanes

• 1. Alkanes with at least one carbon branch,
  substituent, or side group
• 2. Alkyl group- alkane with one H removed
• 3. Examples- methyl, ethyl, propyl, . . .

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Alkyl Examples

• 1. Methyl
• 2. Ethyl
• 3. Propyl
• . . .

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Alkane Nomenclature, steps 1-3

• 1. Longest unbranched chain is parent chain
• 2. End nearest first side chain is C1 if two
  side chain carbons are same distance from ends,
  assign lowest number in alphabetical order
• 3. Number name each side chain attached to
  parent chain

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Alkane Nomenclature, step 4

• 1. Write number name of side chains in front of
  parent chain
• a. Use prefixes if identical side chains,
  commas separate numbers, dashes separate names
  numbers
• b. Alphabetize side chains, dashes separate
  names numbers

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Nomenclature Example 1, step 1

• Name parent chain
• pentane

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Nomenclature Example 1, step 2

• 2. Number parent chain

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Nomenclature Example 1, step 3

• 3. Number name side chains
• 2-methyl 3-methyl

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Nomenclature Example 1, step 4

• 4. Write out full name
• 2,3-dimethylpentane

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Nomenclature Example 2, step 1

• Name parent chain
• hexane

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Nomenclature Example 2, step 2

• 2. Number parent chain

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Nomenclature Example 2, step 3

• 3. Number name side chains
• 4-ethyl 2-methyl

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Nomenclature Example 2, step 4

• 4. Write out full name
• 4-ethyl-2-methylhexane

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Alkane Name to Structure

• 1. 2,3-dimethylhexane
• 2. 2,3,3-trimethylhexane

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Structural Isomers

• 1. Compounds with identical molecular formula but
  different structure, therefore different
  properties
• C4H10

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Cycloalkanes

• 1. Alkanes with carbons in a ring, all single
  bonds
• Cyclohexane

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Cycloalkane Nomenclature

• 1. Prefix cyclo- added to alkane name of ring
• 2. If one side group, no number is used
• 3. If two or more side groups, number to give
  lowest values
• 1,2,4-trimethylcyclohexane

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Aromatics

• 1. Cyclic compounds with hybrid or resonance
  single double bonds
• 2. Benzene most common
• or

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Aromatic Nomenclature

• 1. Name parent ring, add group name as prefix
• 2. Methylbenzene (toluene), chlorobenzene
• 3. Ortho, meta, para or numbered

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Aromatic Examples

• 1,2-dimethylbenzene 1-chloro-3-methylbenzene
• (o-dimethylbenzene)

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