1. Chemistry 101 H. Introduction to Organic. Chemistry. This presentation was
created by. Professor Carl H. Snyder. Chemistry Department. University of Miami.
Chemistry 101 H Introduction to Organic Chemistry
Chapter 6 - Introduction to Organic Chemistry
This presentation was created by Professor Carl H. Snyder Chemistry Department University of Miami Coral Gables, FL 33124
[email protected] Copyright 2004 by Carl H. Snyder, University of Miami. All rights reserved.
“Organic” in Everyday Life What do we mean by organic foods? organic gardening? organic pesticides?
“Organic” in Chemistry
“Organic” and “Vital Force” Before 19th Century, belief was: Compounds present in plants and animals required a “vital (life) force” for their creation. 1828, Friedrich Wohler carried out a laboratory synthesis of urea, a biological product formerly believed to be a product of the “vital force”. Wohler’s laboratory synthesis of urea signalled the beginning of the end of the “vital force” theory.
The Hydrocarbon Family
All organic compounds contain carbon. If a compound contains carbon, it’s an organic compound. Inorganic compounds do not contain carbon.
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Our Most Common Hydrocarbons Gasoline is our most common consumer product consisting principally of hydrocarbons. Others include: mineral oil lubricating oil petroleum jelly
Methane and The Tetrahedral Carbon
Methane Methane, CH4, is the simplest member of the hydrocarbon family
Four hydrogen atoms form four covalent bonds with one carbon atom
The Methyl Free Radical
The stereochemistry of methane is tetrahedral. Four hydrogens lie at the apexes of a tetrahedron. The carbon lies at the center of the tetrahedron.
The distinguishing characteristic of a free radical is that it contains an unpaired electron.
Ethane
The 3-Dimensional Structure of Ethane
The combination of 2 methyl free radicals forms ethane. Ethane can be formed in a variety of other ways as well.
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Three Ways to Draw the Structure of Ethane
The first shows explicitly the C-C and all the C-H bonds. The second shows explicitly only the C-C bond.. The third is the most common way of drawing ethane’s structure.
Space-filling Models of Methane and Ethane
Propane and The Alkanes
methane, CH4 ethane, C2H6 propane, C3H8 are the first 3 members of the alkane family. All alkanes have the general formula CnH2n+2
From One Methane to One Ethane All 4 hydrogens of methane are mutually equivalent. Replacing any one of methane’s hydrogens with a methyl group gives rise to the same ethane molecule.
From One Ethane to One Propane
Propane - Two Different Kinds of Hydrogens The propane molecule contains two different kinds of hydrogens: The methyl group's 6 primary (1o) hydrogens The methylene group’s 2 secondary (2o) hydrogens
All six of ethane’s hydrogens are mutually equivalent. Replacing any one of ethane’s hydrogens with a methyl group gives rise to the same propane molecule.
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From One Propane to Two Different Butanes Replacing a 1o H with a methyl group gives butane Replacing a 2o H with a methyl group gives isobutane.
Isomers Butane, C4H10 , and isobutane, C4H10 , are isomers.
The First Five Alkanes - A Summary
The First 10 Straight-Chain Alkanes
The C5H12 Alkanes - Structures
Isomeric Alkanes
Left: pentane, the only straight-chain pentane Center: isopentane, a pentane with one branch Right: neopentane, a pentane with two branches
By one estimate, there are as many possible isomers of C100H202 as there are atoms in the universe.
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IUPAC - #1
IUPAC - #2
IUPAC - #3
IUPAC - #4
IUPAC - #5
Alkenes
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Ethene, or Ethylene
The C-C Single Bond and The C=C Double Bond Covalent bonding in ethane and in ethene (ethylene).
Removal of a molecule of hydrogen from ethane produces ethene (IUPAC), or ethylene (common).
Where Is The Double Bond? Give the C=C double bond the number held by the lower numbered carbon. If the C=C bond lies between C#1 and C#2, we have 1-butene. If between C#2 and C#3, we have 2-butene.
Alkanes, Alkenes, and Alkynes A Summary
Alkynes - Ethyne, or Acetylene
An alkyne contains a triple bond.
Saturation and Unsaturation
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Saturation and Unsaturation in Ethane and Ethylene
Addition of H2O to C=C
H2 can be added to C=C double (and triple) bonds.
Water can be added to C=C The product is an alcohol.
Cycloalkanes
Benzene, An Aromatic Hydrocarbon
Left: All bonds and all atoms are shown Center: Only C-C and C=C bonds are shown Right: The 6 electrons of the C=C system appear as a circle.
Aromatic Compounds
Some Important Aromatic Compounds
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The Hydrocarbon Family
A Burning Candle
The Chemistry of a Charcoal Grill
Balanced Equations
As the carbon of the charcoal briquettes in a backyard grill burns: One atom of carbon and one diatomic molecule of oxygen combine to form one molecule of carbon dioxide: 1C + 1O2 ---> 1CO2 or more simply C + O2 ---> CO2 The reaction releases heat.
Carbon dioxide formation: C + O2 ---> CO2 C + O=O ---> O=C=O
Carbon monoxide formation: 2 C + O2 ---> 2 CO C, C, O=O ---> CO, CO
End - Chapter 6
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