Organic Compounds
• Organic compounds are molecules that contain carbon.
• Carbon is the base of organic compounds for 3 reasons:
1. Carbon forms stronger covalent bonds than most other non-metals
2. Carbon forms more stable molecules than most other non-metals
3. Carbon can form up to 4 bonds at a time, which gives many possibilities for molecules.
Structure of Organic Compounds• Besides carbon, the most common elements in organic compounds are: H, O, N, S, & halogens.
• Organic compounds are held together with covalent bonds.
• Organic compounds must meet the octet rule (S does not break the octet rule)
Hydrocarbons
• Hydrocarbons are the most simple organic compounds
• Hydrocarbons only contain C & H• All other organic compounds are derivatives of
hydrocarbons• Petrochemicals contain hydrocarbons, including:
propane, butane, and octane• Saturated – a compound is termed “saturated” if it has
the maximum hybridization (sp3) at each carbon!
Therefore: no double or triple bonds
HydrocarbonsC2H6
Alkanes• Single bonded carbons
• Strongest, most stable hydrocarbo
ns
• CnH2n+2
• saturated
C2H4
Alkenes• A double bonded carbon
• Weaker, less
stable hydrocarbons
• CnH2n
• unsaturated
C2H2
Alkynes• A triple
bonded carbon
• Weakest, least stable hydrocarbo
ns
• CnH2n-2
• unsaturated
C6H6
Aromatics
Ring of carbons
with alternating double
and single bonds
C6H12
cycloalkane• ring
• CnH2n
• unsaturated
Simple Organic NomenclaturePrefixes used with organic
compounds1. meth- 6. hex-2. eth- 7. hept-3. prop- 8. oct-4. but- 9. non- 5. pent- 10. dec-
Name the following organic compoundsa. CH4 ___________________
b. C3H8 ___________________
c. C3H6 ___________________
d. C4H10 ___________________
e. C5H8 ___________________
f. C3H4 ___________________
methanepropane
propene
butanepentynepropyne
Suffixes used with organic compounds
-ane = CnH2n+2
-ene = CnH2n
-yne = CnH2n-2
Nomenclature RulesProcedure for naming carbon chains containing branches or substituents (non-straight chain)1) Find the longest continuous carbon chain in the structure-this determines the root name
2) Any carbon not on this continuous chain is a substituent (appendage)3) Number the main chain starting from the end closest to the first substituent4) The substituents are still named according to the number of carbons(the suffix for a substituent is –yl instead of –ane)
-CH3 methyl-CH2CH3 ethyl
5) Place all substituent names before the root name in alphabetical order6) The substituent must be numbered to indicate the point of attachment to the main chain7) Group multiple substituents of the same kind together and label di-, tri-, etc.8) When alphabetizing, the prefixes di-, tri- are ignored9) With a ring compound the number of carbons in the ring determines the root name with a cyclo- prefix10) Halogens are named as substituents with an -o suffix
e.g. fluoro-, chloro-, bromo- or iodo-
Isomers - Compounds with the same molecular formula but different structural arrangement therefore a different name.
A. hexaneB. 2-methylpentane
C. 3-methylpentaneD. 2, 2-dimethylbutane
E. 2,3-dimethylbutane
C6H14
1-Butene
3-Heptyne
Draw & Name the following
C
H
H
H
HC C C
H
H HH
C
H
H
H
HC C C
H
H H
C C C
HHH
H H
C4H8
C7H12
C3H6 or CH3CH=CH2
C4H8 or H2C=CHCH2CH3
CH
H
H
CH
C
H
1-propene
H
H
H
H
H
C C
H
CH
CH
1-Butene
H
Functional Groups
• Functional groups are any atom, group of atoms, or organization of bonds that determine the properties of a molecule.
• Functional groups are the most reactive part of a molecule
• Functional groups directly determine the properties of a molecule
Functional Groupsa. Alcohols: -OH
When carbon is single bounded to an –OH Ex. Propanol
3-pentanol
Add –ol to name
H
H
H
H
C C
H
H
C
H
O••••
H
b. Aldehydes: -C=OH - always on the endExample:
c. Carboxylic Acids: COOHMost common organic acids belong to this group.Example:
pentanal
Add –al to name
Propanoic Acid
Add –oic Acid to name
d. Ketones: -C=O (also called a carbonyl group)
Example:
e. Esters are formed when a carboxylic acid reacts with an alcohol. This reaction is called esterification.
–O-C=OExample:methyl butanoate
Add –oate to name
Smells like pineapple
4 -octanone
Add –one to name
f. Halohydrocarbons: Halogen substituted for a hydrogen
Example:
F
H
Br
F
C C
Cl
F
2-bromo-2-chloro-1,1,1-trifluoroethane.
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Polymers
• Polymers are long carbon chains made of repeating units
• Both natural and synthetic (man-made)
Natural Polymer Examples
•Nucleic Acids• Examples: DNA, RNA
• Carbohydrates• Examples: starches, sugars
• Enzymes (protein catalysts that speed up chemical reactions)
• Example: lactase• Vitamins (naturally in plants & animals)• Insulin (naturally made in your body)
Synthetic Polymer Examples
• Plastics (made from petrochemicals)
• Examples: polystyrene, Styrofoam, polyvinyl chloride (PVC), nylon
• Kevlar (used in ballistic vests and combat helmets)• Pharmaceuticals
• First synthetic pharmaceutical was aspirin