Transcript ORGANIC CHEMISTRY

ORGANIC
CHEMISTRY
The scientific study of the structure,
properties, composition, reactions, and
preparation (by synthesis or by other
means) of chemical compounds consisting
of primarily carbon and hydrogen, which
may contain any number of other elements,
including nitrogen, oxygen, halogens as
well as phosphorus and sulfur.
~Wikipedia
What is Organic Chemistry?
Chemistry of the compounds of carbonwith a few exceptions (CO, CO2,
carbonates, hydrogen carbonates
cyanide and HCN)
Many derived from living things and
involved in life processes.
About 8 million organic compounds
known, but more than 3,500 new organic
compounds are being reported every
week.
Functional Groups
Determine the reactivity of organic
compounds
An atom or group of atoms which is
characteristic of a class of organic
compounds and which determines the
properties of the class.
Important in classifying or systemizing
organic compounds
Main Types of Functional Groups
Hydrocarbons
Polar Single Bonds
Carbon-Oxygen Double Bonds
Hydrocarbon Functional Groups
Compounds which contain only carbon
and hydrogen
Three Main Types
Aliphatic- Most hydrocarbons
Alicyclic-Aliphatic compound which
contains rings consisting of only carbon
and hydrogen.
Aromatic-Benzene like in character and
properties
Aliphatic Hydrocarbons
Alkanes
Characterized by having only single bonds
Alkenes
Characterized by having a carbon-carbon double
bond
Alkynes
Characterized by having a carbon-carbon triple
bond
Alkanes
Serve as a backbone for functional groups
Nonpolar so are soluble in other nonpolar solutions
Saturated compounds because they have full number
of hydrogens
Boiling point increase with number of carbons
Straight and Branching chains
Straight chains
All names end in “ane” with prefix according to number of
carbons (meth-1, eth-2, prop-3, but-4, pent-5, hex-6, hept7, oct-8, non-9, dec-10)
To write molecular formulas, use CnH2n+2
To draw structural formulas, write the symbol for carbon as
many times as necessary and then fill in with hydrogens.
Practice Problems #1-3 pg 747 & 749
Branched Chain
Alkyl group substituents, added to straight chain
(use same prefix for number of carbons)
Follow IUPAC rules for naming
Find the longest chain of carbons in the molecule this
will be the parent chain and end in “ane”
Number the carbons in the parent chain, starting at
the end where the most branches are.
Determine substituents names and add numbers for
where they appear on the parent chain.
Use prefixes to indicate the appearance of a group
more than once in the structure.
For drawing structures draw carbons first then
add hydrogens.
Practice problems #4-6 pg 750
Alkenes
Hydrocarbons containing carbon-carbon double
covalent bonds
Unsaturated compounds because they don’t have
full number of hydrogens
To name alkenes by IUPAC system
Find longest chain that has double bond in it, use
prefix from alkanes but add “ene” instead of “ane”
Start numbering the parent chain from the end that
makes the double bond have the lowest number.
Follow other rules for alkanes but add a number at
beginning of parent name to show where double bond
is.
Practice problem #35 pg 768
Alkynes
Hydrocarbons containing carbon-carbon
triple covalent bonds
Unsaturated compounds because they
don’t have full number of hydrogens
To name alkynes by IUPAC system use
same rules as alkenes but use “yne”
ending instead of “ene”.
Isomers
Structural Isomers
Compounds that have the same molecular formula but
different molecular structures
Differ in physical properties (BP & MP) and reactivity
Ex: C4H10 can be butane or 2 methyl propane
Geometric Isomers
Differ only in the geometry of their substituents.
Alkenes are fairly structured due to their double bonds.
Therefore, there are two arrangements of the
substituents, cis and trans, that are noted in naming.
Cis configurations- place the substituents on the same side of
the double bond
Trans configurations-place the substituents on the oppostie sice
of the double bond.
Practice problems #38-39 pg 768
Stereoisomers
Compounds of the same molecular structure
that differ only in the arrangement of the
atoms in space.
Contain a asymmetrical carbon
Compounds are nonsuperimposable mirror
images of each other.
Practice problems #14-15 pg 756
Alicyclic
In some cases, the two ends are attached
to form a ring.
Rings contain 3 to 20 carbons, but most
are 5 or 6 carbons.
Naming for Alicyclic compounds are the
same as alkanes except that you add
cyclo to the front of the parent name.
Aromatic
Unsaturated rings of carbon that have double
bonds so not as many hydrogens as possible.
Benzene is the most simple form that has the
molecular formula C6H6.
Other aromatics either have the benzene as the
parent part of the compound or the benzene is a
substituent on a hydrocarbon chain.
If the benzene is the main part of the compound,
the substituents are then named as usual picking
one of the substituents as position 1.
If the benzene is a substituent is part of a chain
then it is called a phenyl group.
Practice problems #20 and 23 pg 761
Polar Single Bond Functional
Groups
Compounds that only have single bonds
but now include many other atoms in
addition to carbon and hydrogen.
Main Types include…
Halocarbons
Alcohols and Phenols
Ethers
Amines
Halocarbons
Compounds of carbon and hydrogen that also
contain covalently bonded fluorine, chlorine,
bromine or iodine (halogens).
These compounds are also called alkyl halides
due to their common names.
Have higher boiling points than hydrocarbons
Using IUPAC naming rules, all have single bonds
so parent chain name is the same as alkanes.
Then the “ine” is taken off of the halogen and
replaced with “o” and put in front of the parent
name.
A number is then placed in front of the halogen
depending on where attaches to the chain.
Practice problem #3 pg 777 and #22 pg 804
Alcohols and Phenols
Alcohol have a OH group attached to a carbon in a
hydrocarbon chain and Phenols have an OH group
attached to an aromatic hydrocarbon ring (benzene
becomes benzenol).
Boil at higher temps than hydrocarbons and halocarbons
Some are soluble in water (those with 4 or less carbons).
Both IUPAC and common names are used for Alcohols.
Naming with IUPAC system: find the longest chain of
carbons that includes the one attached to the OH, replace
the “e” of the parent name with “ol”.
If there are more than 1 OH substituents the ending
changes to 2-diol, 3-triol, 4-tetrol
Common names have the alkyl group followed by “alcohol”.
It can be a primary, secondary or tertiary alcohol due to the
number of substituents attached to the carbon the OH is
attached to.
Practice problems #10 and 11 a & b
Ethers
Compounds in which oxygen is bonded to
two carbon groups or chains.
Naming is fairly simple… the alkyl groups
attached to either side of the oxygen are
named in alphabetical order and followed
by the word ether.
When both groups are the same on each
side the ether is symmetrical and a di is
put on the front of the name
Practice problems #11 d & c pg 784 #27
pg 804
Amines
A compound that has a nitrogen attached to at
least one hydrocarbon group.
Primary amines only have one group
(R-NH2)
Secondary amines have two groups
(R-NH-R)
Tertiary amines have three groups
(R-N-R)
R
Naming is the same as ethers except you use
the word amine instead of ether at the end
Carbon-Oxygen Double Bond
Functional Groups
Compounds that contain a carbonyl group
which is a carbon that is joined with an
oxygen by a double bond.
Main types include…
Aldehydes
Ketones
Carboxylic Acid
Esters
Amides
Aldehydes
Compound in which the carbon of the
carbonyl group is always joined to at least
one hydrogen.
Those with 3 or less carbons are soluble in
water.
Have higher boiling points…
Using the IUPAC system, find the longest
hydrocarbon chain that contains the
carbonyl group. The “e” ending of the
hydrocarbon is replaced by “al”.
Practice problems #16 a & c pg 794
Ketones
Compound in which the carbon of the carbonyl
group is joined to two other hydrocarbon groups
Using the IUPAC system, find the longest
hydrocarbon chain that contains the carbonyl
group. The “e” ending of the hydrocarbon is
replaced by “one”.
If the carbonyl group of a ketone could occur at
several places on the chain, then its position is
designated by the lowest possible number.
Practice problem #16 b & d pg 794
Carboxylic Acids
Compounds with a carboxyl group, which is a
carbonyl group attached to a hydroxyl group (OH).
Weak acids because they ionize only slightly in
solution to give a carboxylate ion and a hydrogen
ion.
Using the IUPAC system, replace the “e” ending
of the longest continuous carbon chain containing
the carboxyl group with the ending “oic acid”.
Many continuous chain carboxylic acids were first
isolated from fats and are called fatty acids.
Common names are often used more than IUPAC
names. (Table 26.6 on pg 789)
Practice problems #35 pg 805 (use both common
and IUPAC names)
Esters
Compounds that contain a carbonyl group and an
ether link to the carbonyl carbon.
Many esters have pleasant, fruity odors and give
most fruits their lovely odors.
Lower boiling points…
Can be hydrolyzed by the addition of water to
produce a carboxylic acid and an alcohol.
Using the IUPAC system, find the longest chain
that has the carboxyl group and add a “oate” on
the end instead of an “e”.
Add the alkyl group from the other side of the
oxygen to the front of the parent name.
Amides
A compound that has a nitrogen attached
to a carbonyl group.
Primary amides only bond to hydrogens
and the carbonyl group (carbonyl-NH2)
Secondary amides have one hydrogen
and one carbon group bonded to the
nitrogen (carbonyl-NH-R)
Tertiary amides have two carbon groups
bonded to the nitrogen (carbonyl-N-R)
R
Additional substituents…
Isopropyl
Prefix iso is used when there is a methyl group on the carbon second
from the unsubstituted end of the longest chain
Isobutyl
The carbon joining this alkyl group to another group is bonded to one
other carbon, it is a primary carbon
Sec-butyl
The carbon joining this alkyl group to another group is bonded to two
other carbons, it is a secondary carbon.
Tert-butyl
The carbon joining this alkyl group to another group is bonded to three
other carbons, it is a tertiary carbon
Vinyl
When used as an alkl group in giving compounds common names
ethene (without one hydrogen) is called a vinyl
Phenyl
When benzene is used as an alkyl group.