Transcript organic chemistry

ORGANIC
CHEMISTRY
Organic Chemistry
• Study of carbon and carbon compounds
• Organic compounds contain carbon
atoms which covalently bond to each
other in chains, rings, and networks to form
a variety of structures
General Characteristics of Organic
Compounds
• Nonpolar
• Soluble in nonpolar solvents / insoluble in
polar solvents (water) “Like dissolves Like”
• Poor conductors of heat and electricity
– Exception: aqueous organic acids conduct
• Low melting and boiling points
• React slower than inorganic compounds
– High activation energies
• Molecular Formulas
– Indicates the kind and number of atoms of each
element in the compound
– Example: C2H6
• Empirical Formulas
– Reduced formula, in lowest terms
– Example: What is the empirical formula for
C4H10
• Structural Formulas
– Attempts to show the bonding patterns and
approximate shapes
– Ex:
• Condensed Structural Formulas
– Shows the connections without showing the
shape and bonds
– Ex:
Bonding
• Carbon- has 4 valence electrons, needs 4
more, forms 4 bonds
• Oxygen – has 6 valence electrons, needs 2
more, forms 2 bonds
• Hydrogen – has 1 valence electron, needs 1
more, forms 1 bond
• Halogens (group 17) – has 7 valence
electrons, needs 1 more, forms 1 bond
Homologous Series (Families)
• Group of related compound in which each
member has one more group
– Ex: CH3CH2CH3 and CH3CH2CH2CH3
• Members of a group will have similar structures
and properties
• As the members of a series increase in mass, their
boiling (and melting) points increase – due to
increased intermolecular forces
Hydrocarbons
• Organic compounds that contain only
CARBON and HYDROGEN
ALKANES...
SINGLE bonds between Carbons
Saturated hydrocarbon
CxH2x+2
Family Name
ALKENES...
ONE DOUBLE bond between two Carbons
ALKYNES...
ONE TRIPLE bond between two Carbons
Unsaturated hydrocarbon
Unsaturated Hydrocarbon
CxH2x
CxH2x-2
PREFIXES
…counting the CARBONS
ALKANES
• Contain all single bonds
• Naming: carbon prefix + -ane
Example: Ethane
Butane
Octane
C4H10
ALKENES
• Contain 1 double bond
• Naming: carbon prefix + -ene
– A number is used in front to indicate the
location of the double bond
– If a number is not indicated the double bond
comes after the 1st carbon
Example: 2-Pentene
Diene
• Contains 2 double bonds
• Naming: location-carbon prefix-diene
Propadiene
• Example: 1,3-pentadiene
C3H4
ALKYNES
• Contains 1 triple bond
• Naming: carbon prefix + -yne
Example: Ethyne
Ethyne
Propyne
• Saturated Compounds – contains all single
carbon-carbon bonds
• Unsaturated Compounds – contains at least
multiple carbon-carbon bond
Branched Hydrocarbons
• Contain 1 or more branches off the main chain
Methyl group on carbon 4
8
7
6
5
4
3
2
4-methyl-ocatane
1
Naming Branched Hydrocarbons
• Find the longest continuous chain, name it
• To name the branches: number of carbons + “-yl”
– Examples:
• CH3 = methyl
• CH2CH3 = ethyl
• The location of the alkyl (branched group) is
indicated
– If there is more than one of the same branch, use
prefixes (di, tri, tetra, …)
– The carbon chain must be numbered from the end that
will give the lowest numbers for the branches
Example: 2, 2, 3 – trimethyl pentane
SAME…BUT DIFFERENT
• Same – number and type of atoms
• Different – structure and name
Have different physical and chemical properties
2 CARBONS
6 HYDROGENS
1 OXYGEN
ETHANOL
DIMETHYL ETHER
a primary alcohol
C2H5 OH
CH3OCH3
GROUPS
and
COMPOUNDS
• Functional Group: halogen (group 17 element)
• Name: location-halide-carbon chain
• Examples:
1. 2-bromobutane
2. 1,3 - dichloropentane
ALCOHOLS
•
•
•
•
•
Functional Group: -OH
No more than one –OH group can be attached to any one
carbon
The carbon to which the –OH group is attached must have all
single bonds
Alcohols are not bases (do not ionize in water)
Name: hydrocarbon name, replace the final –e with –ol
Examples:
1. Methanol
2. 2-Propanol
Types of Alcohols
• Monohydroxy – contain 1 –OH group
– Primary
– Secondary
– Tertiary
• Dihydroxy (Diol) – contain 2 –OH groups
• Trihydroxy (Triol) – contain 3 –OH groups
Primary Alcohols
•
•
•
Contain 1 –OH group
-OH group is attached to the end of the
chain
Examples:
1. Ethanol
2. Propanol
H
SECONDARY ALCOHOL
•Contain 1 –OH group
R-C-R
O
H
•Carbon that is attached to the –OH group is
attached to 2 other carbon atoms
2-Butanol
4 CARBONS
-OH GROUP ON SECOND
CARBON FROM RIGHT
R
TERTIARY ALCOHOL
R-C-R
O
•Contain 1 –OH group
H
•Carbon attached to the –OH group is attached
to three other carbon atoms
Methyl group
2METHYL,2-BUTANOL
Ethyl group
Methyl group
-OH GROUP ON SECOND
CARBON FROM RIGHT
4 CARBONS in sequence
2 -OH groups are present
1,2 ethanediol
3 -OH groups are present
1,2,3 propanetriol
•Functional Group = -COOH
•Name: Hydrocarbon name, drop the final “e” and
replace it with “–oic” followed by the word “acid”
•Examples:
1. Ethanoic Acid
2. Butanoic Acid
CH3COOH
• Functional Group: -CHO
• Name: drop the final “e” and add “-al”
ethanal
2 carbons
alkane aldehyde
Propanal
CH3CHO
• Functional Group: -CO• Name: Hydrocarbon name, drop the final “e”, add
“one”
Propanone
CH3COCH3
2-Butanone
• Functional group: -O- (chain-O-chain)
• Name:
1. Name each hydrocarbon chain – drop the
ending add “yl”
2. Add “ether” to the end
diethyl ether
Ethyl methyl ether
C2H5OC2H5
• Functional Group: -COOR
• Formed from a dehydration reaction of an alcohol
and an acid
• Fruity odor
• Name:
• Name each hydrocarbon chain
– The part with the –CO gets the “-oate” ending
– The other part gets the “-yl” ending
Ester Examples
• Ethyl Methanoate
HCOOC2H5
• Ethyl Ethanoate
• Functional Group: NH2
• Name the chain, add “amine” to the end
ethanamine
C2H5NH2
• Functional Group: R-CONH2
• Name: Name the chain, add “amide” to the
end
Butanamide
Propanamide
C3H7CONH2
• Functional Groups: -NH2 and –COOH
• Just like an alcohol, but –SH instead of –
OH
Example: Methyl Thiol (CH3SH)
ADDITION
SUBSTITUTION
ESTERIFICATION
SAPONIFICATION
POLYMERIZATION
COMBUSTION
FERMENTATION
• Something takes the place of
something else
• Starts with a saturated
hydrocarbon
C2H 6
Cl2
C2H4 Cl2
H2
• Start with an unsaturated hydrocarbon
• Break the double (or triple) bond
• Add in an atom (or group)
C 2H 4
Cl2
C2H4 Cl2
Concentrated H2SO4
acts as a dehydrating agent
ORGANIC ACID + ALCOHOL
C2H5 COOH
H2SO4
CH3 OH
ESTER +
WATER
C2H5 COOCH3
H 2O
• Reverse of esterification, carried
out in the presence of a base
• See p.169 for an example
FAT
(glycerol ester)
Strong base
(NaOH or KOH)
SOAP
glycerol
(trihydroxy alcohol)
1,2,3 propane triol
C6H12 O6
GLUCOSE
ZYMASE
C2H5 OH
ETHANOL
CO2
CARBON
DIOXIDE
• Hydrocarbon + O2
• Exothermic
Example:
C2H6 + O2
CO2 + H2O
Poly...poly...poly…poly...poly...polymerization
• Chains of small units make up a
MACROMOLECULE
• Examples: Plastics, proteins
Condensation Polymerization
• Bonding of monomers by a dehydration
reaction
– OH groups of adjacent alcohols react, water is
removed, the 2 molecules are connected by the
remaining O
• Examples: Nylon, Protein, Polyester
Addition Polymerization
• Bonding of monomers of unsaturated
compounds by “opening” a multiple bond in
the carbon chain
• Example: polyethylene and many plastics
n C 2H 4
(C2H4)n