Transcript Organic Chemistry

Organic Chemistry
Carbon
• Has 4 valence electrons
• Can have sp3 hybridization where substituted
groups are at 109.5o to one another.
• Other hybridizations are possible.
• Usually shares electrons
• Can easily bond to itself and many other
elements
• Can make straight chains of carbons or
branched chains
• Can form single, double, and triple bonds to
itself and to some selective other atoms
• Can polymerize
Alkanes
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Contain only carbon and hydrogen
Have only single bonds.
Tetrahedral geometry
Characteristic reactions
– Halogenation
• R-H + X2  R-X + HX
• Chlorine >Bromine
• Tertiary>Secondary>Primary
– Combustion
• R-H + O2  CO2 + H2O
– Pyrolysis(cracking)
• Alkane  H2 + smaller alkanes + alkenes
Alkanes
• Nomenclature – ending is ane.
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Meth
Eth
Prop
But
Pent
Hex
Hept
Oct
Non
Dec
Alkyl Groups
Alkenes
• Contain only carbon and hydrogen
• Have one double bond between two carbons.
• The double bond makes alkenes unsaturated with respect to
hydrogen.
• Trigonal planar geometry
• If there are two or three double bonds
– Alkadiene
– Alkatriene
• Characteristic reactions
– Addition
– C=C + Y-Z  C-C
Y Z
Alkenes
Alkenes
• Structural isomers are those which have the
same chemical formula but differ in how the
atoms are attached to one another.
• A cis-isomer has the two substituted groups on
the same side of the double bond.
• A trans-isomer has the two
• substituted groups on
• opposite sides of the double
• bond.
Alkenes
• Characteristic Reactions
– Addition of hydrogen
– Addition of halogens
– Addition of hydrogen halides
– Addition of sulfuric acid
– Addition of water
Alkenes
• Nomenclature – end with ene
– Eth
– Prop
– But
– Pent
– Hex
– Hept
– Oct
– Non
– Dec
Alkynes
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Contain only carbon and hydrogen
Contain one triple bond between carbons
Linear geometry
Characteristic reactions of alkynes
– Addition of hydrogen
– Addition of halogens
– Addition of hydrogen halides
– Addition of water
Alkynes
• Nomenclature – end with yne
Functional Groups
• Hydrocarbons may have functional groups
substituted for hydrogens.
• Such substitutions give carbon the
capacity to form many, varied compounds
with different reactivities from the original
hydrocarbon.
• The possibilities are nearly endless.
Alkyl Halides
• RX
– Give the number of the carbon where
the halide(s) appear.
– Give the name of the halide (chloro,
bromo, iodo)
– Write the name of the longest chain of
carbons.
– C5H10Cl2 dichloropentane (must have
structure to determine the numbers of
carbons that are substituted)
Alcohols
• ROH
– Give the name of the longest chain of carbons
and end with –ol.
– Primary – carbon with OH is connected to one
other carbon
– Secondary – carbon with OH is connected to two
other carbons
– Tertiary – carbon with OH is connected to three
other carbons
– C5H11OH – pentyl alcohol or
pentanol(structure needed to determine
number)
Aldehydes
• RCHO
– Write the name of the longest carbon chain
and add -al for the ending.
– Remember that the functional group here
must be on the last carbon in the molecule.
– C5H10O - pentanal
Ketones
• RCOR`
– Write the name of the longest carbon chain
and end with -one.
– Remember that the functional group, the
carbonyl (C=O) cannot be on the end of the
molecule.
– Example
Carboxylic Acids
• RCOOH
– Write the name of the longest carbon chain
and end with –oic acid.
– Remember that the functional group (COOH)
must be on the end of the molecule.
– These are organic acids and they contain one
ionizable hydrogen.
– Example
Esters
• RCOOR`
• Write the name of the group (R`) and end
it with –yl.
• Then write the name of the R-C group and
end it with –oate.
• Example
Ethers
• ROR`
• Write the name of one of the R groups and
then the name of the other one in
alphabetical order.
• End with –ether.
• Example
Cyclic compounds
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Cycloalkanes
Cycloalkenes
Cycloalkynes
Example
Aromatic Compounds
• These must contain a benzene ring.
• Benzene is C6H6 and may be indicated in
several different ways.
• Positions on the ring may be indicated by
ortho(1,2 positioning), meta(1,3
positioning), and para(1,4 positioning)
prefixes.
• Examples
Amines
• RNH2 – primary amine
• RNR` - secondary amine
H
• RNR` - tertiary amine
R
• These are organic bases.
• They will combine with carboxylic acids to make
amino acids, the building blocks of proteins.
• Examples
Amides
• RCONH2
• Write the name of the carbon chain and
end with amide.
• Examples
Thiols
• RSH
• May be primary, secondary and tertiary.
• Analogs of alcohols so they will do the
same reactions.
• Name the longest carbon chain and
maintain the ending.
• Add the word thiol to it.