1. 7.3 – Functional Groups Part 1 – Halocarbons & Alcohols

2. Functional Groups
Functional groups are groups of atoms found within molecules that are involved in the chemical reactions characteristic of those molecules.
Hence the name, they are simply groups of atoms that can be attached to a hydrocarbon chain and have a specific FUNCTION
This allows for different characteristics, reactions, etc.
Functional groups can pertain to any molecules, but you will usually hear about them in the context of organic chemistry.
The symbol “R” refers to a hydrogen or hydrocarbon side chain that is attached to a functional group

3. Functional Groups Type Structure Functional group Halocarbon
R-F (Cl, Br, or I)
halogen
Alcohol
R-OH
hydroxyl װ װ

4. Halocarbons
Halocarbons are organic compounds that contain one or more covalently bonded halogens.
The functional group is the halogen atom
Halogens include:
Fluorine
Chlorine
Bromine
Iodine

5. Naming Haloalkanes IUPAC names for halogen substituents are:
Fluorine = fluoro-
Chlorine = chloro-
Bromine = bromo-
Iodine = iodo-
The halo-substituents are numbered and arranged alphabetically, like we did before

6. Nomenclature of Halogens
Number the main (longest) carbon chain so that the halogen will have the lowest number.
Number the position of the halogen.
Alkanes always end in ane.
Use the same prefixes as before to name the main carbon chain.
If there are alkyl groups in addition to halogens attached to the main chain; the halogen’s position and name come first when naming.

7. Types of Halocarbons:
Primary Halocarbons where a halogen is on a carbon attached one other carbon

8. Types of Halocarbons
Secondary Halocarbons: the halogen is on a carbon that is attached to two other carbons

9. Types of Halocarbons
Tertiary Halocarbons: halogen is on a carbon that is attached to three other carbons

10. Other substituents Use the same naming rules
Number position on the parent chain
Put in alphabetical order
2-chlorobutane
3-bromo-2-chlorobutane
Also, 2,2-dibromo-4-methylpentane is a good example of knowing which end to count from

11. Haloalkanes - Examples
An alkane in which halogen atoms replace one or more hydrogens
Used as solvents and anesthetics
CFC’s (chlorofluorocarbons) were used a propellants in aerosols
React with ozone in the upper
atmosphere
Resulted in ozone depletion
over the Antarctic

12. Alcohols
Alcohols are compounds in which one or more hydrogen atoms in an alkane have been replaced by a hydroxyl group. (-OH)
  The name of the alkane chain loses the terminal "e" (from ane)and adds "ol",

13. Nomenclature of Alcohols
Naming and Numbering Alcohols:
The longest chain of carbon atoms containing the –OH group is selected as the parent.
alkane chain is numbered from the end closer to the –OH group.
To show the compound is an alcohol, the suffix –e of the parent alkane is changed to –ol.

14. Nomenclature of Alcohols
Naming and Numbering Alcohols:
A number is used to show the location of the –OH group.
In the numbering of the parent chain, the location of the –OH group takes precedence (given the lowest number)over alkyl groups and halogen substituents
For cyclic alcohols, numbering begins at the carbon bearing the –OH group.

15. Alcohols
Examples of alcohols:
Methanol Ethanol 2 1 1

16. Alcohols

17. Designation of Alcohols
Much like halocarbons, alcohols can be designated as primary, secondary or tertiary based on the extent of carbon substitution
Alcohols
Primary Secondary Tertiary

18. C6H12O6(aq) →2 CH3CH2OH(aq) + CO2(g)
Alcohols - Formation
Fermentation
Fermentation is the production of ethanol from sugars by the action of yeast.
C6H12O6(aq) →2 CH3CH2OH(aq) + CO2(g)
Humans have long taken advantage of this process in making bread, beer, and wine.

19. Alcohol - Formation
In brewing, alcoholic fermentation is the conversion of sugar into carbon dioxide gas (CO2) and ethyl alcohol. This process is carried out by yeast enzymes.
This is in fact a complex series of conversions that bring about the conversion of sugar to CO2 and alcohol.
Yeast is a member of the plant family and in brewing we use the sugar fungi form of yeast. These cell gain energy from the break down of the sugar. The by-product, CO2, bubbles through the liquid and dissipates into the air.
The other by-product alcohol, remains in the liquid which is great for us but not for the yeast, as the yeast dies when the alcohol exceeds its tolerance level.